Wednesday, November 6, 2013

Final Topical Review Paper


LASER: Its Prevalence and Prominence[1]

Glenda Goh Zhi Yan (glenda.goh.2013@economics.smu.edu.sg), Year 1 student, Bachelor of Science (Economics), Singapore Management University.

Executive Summary
Light Amplification by Stimulated Emission of Radiation (LASER) is a device that is capable of generating an intense beam of coherent monochromatic light that can travel over large distances in a specific direction without dispersing (Dasgupta, 2002). Laser light is produced through the process of stimulated emission, where photons are released from excited atoms or molecules and undergo pumping such that energy is introduced into the laser cavity to produce an electromagnetic field. Electromagnetic waves reflect back and forth between the mirrors inside the laser cavity, stimulating further emission of photons with the same phase and frequency that eventually results in an abrupt burst of coherent radiation when the atoms are discharged in a rapid chain reaction (Rouse, 2005).
The prevalence of laser in our contemporary society is characterized by its widespread presence across various industries while its prominence is seen in its increasing importance as a tool harnessed within these different sectors. The context for the prevalence and prominence of laser could be rooted in the discovery of its unique properties that has allowed it to reach exceptional precision and power (Bhawalkar, n.d.), making it immensely valuable and unparalleled in its uses. In addition, the change in consumer taste and preference with the evolving world dynamics has also created an unprecedented growth in the demand for laser.
In this paper, this author will explore the historical rise of laser, its current developments and the resultant implications of laser that includes the risks involved in utilizing this technology. The discussion also encompasses the future considerations in employing laser technology as a solution to the problems faced by mankind or as a tool to enhance the quality of life, where the paper will aim to deal with the management of risks and fears highlighted and predict the potential areas of advancements in the uses of laser that provides for the eventual sustainability of this technology.

1.        Introduction
Laser has assumed a ubiquitous role in modern civilization, dictating our present and shaping our future with its vast applications in the many sectors that make up today’s diverse society. Growing demands coupled with advancements in science and technology has culminated in the extensive development of lasers since the invention of its predecessor, maser, in the 1950s. Currently, there are more than 10,000 different types of lasers, each carrying a different promise in improving the quality of life for mankind. In light of present trends that point towards the popularity of laser as a solution to the many challenges we face and its expansion into more industries than we thought possible, there is a need to learn more about this technology. Moreover, the likelihood of wielding this technology in the future is also highly probable as new uses of laser are being constantly discovered and capitalized on with the cutting edge technology that we now possess. Notably, the extraordinary properties exclusive to laser has given it an advantage over other innovations and made it both a precise and powerful weapon to have, with the increasing cost competitiveness adding viability to its value (Clark, n.d.). As the true potential of laser has yet to be maximized, it is apt to predict that this superior technology is here to stay, making this research extremely relevant. Although applications of laser are abound, what we have generated thus far is merely the tip of the iceberg and mankind has yet to see the best and most of this intriguing technology. However, owing to the innumerable types and uses of this versatile technology, it is wise to narrow down on the main areas that laser has been applied to. Hence, this author will be focusing her discussion on a few key areas to highlight the pivotal role of lasers in leading significant improvements made within these main sectors: medical, military and communications. The reason for choosing different sectors is to cover a diverse range of industries in order to better appreciate the prevalence of laser while the impetus behind the specific selection of major promising sectors is to demonstrate the prominent role that laser has played in leading to breakthroughs that have allowed the aforementioned industries to explore new frontiers.
This paper aims to explore the history of laser since its inception in the 20th century, tracing its evolution from a mere concept to the actualization of this innovation and finally, its rise in prominence and prevalence. Next, the paper examines the current situation that we are in, highlighting the contemporary developments in laser that have helped solve problems and even improved the quality of life for mankind. It also illuminates the way laser technology has revolutionized life on Earth, transforming the future of our health, our national security and our interaction with others. The paper also deals with the possible consequences and complications that can arise from the improper use of laser. This leads to the discussion of future considerations to manage these problems and address fears that man might bear towards this technology. In addition, the paper will underline the future of laser and predict the potential areas of growth that aims to evaluate the sustainability of this technology, in hope to bring to light the relevance and value of laser in the future. Essentially, will laser still be as prevalent and prominent in the future as it is now?

2.        Historical Perspectives
The birth of laser dates back to approximately a hundred years ago in 1917 when Albert Einstein conceptualized the process of “Stimulated Emission”, a fundamental principle that is later found to be behind the construction of the first laser. This theory proposes that the interaction between high-energy atomic molecules and a lower energy electromagnetic wave will lead to a transfer of energy between them that in turn, stimulates the creation of a photon with the same energy and frequency as the subsequent photons emitted. The resultant light is an intense and coherent beam, otherwise known as laser light (“Stimulated emission”, n.d.). Prior to the introduction of laser, the knowledge of stimulated emission based on Einstein’s predictions, first motivated the invention of MASER (Microwave Amplification by the Stimulated Emission of Radiation) in the early 1950s (Halliday & Resnick, 1986, as cited in “What is a maser?”, n.d.). Maser is a device that is capable of generating powerful beams of radiation at short wavelengths by producing coherent electromagnetic waves through amplification from stimulated emission. Pioneered by notable scientists like Charles Townes, the first maser, ammonia maser, was created in 1954. Demonstrations of the first maser at the Columbia University reflected its capability of producing around 10 nanowatts of power, radiating at a wavelength of slightly more than 1 centimeter (Rose, 2010). However, maser carried a limitation that crippled its progress. The wavelength of the light produced through this device was restricted to the microwave region of the electromagnetic spectrum, which meant that maser could only operate at microwave frequencies (“This Month in Physics History: Einstein predicts stimulated emission”, 2005). Moreover, masers required high magnetic fields and difficult cooling schemes to work, reducing its feasibility (Palmer, 2012). This drove the creation of laser that had shorter wavelengths and was able to generate more energy than its predecessor. In 1960, Theodore H. Maiman spearheaded the construction of the first laser, the ruby laser. It is termed as such because the ruby laser is made up of a ruby crystal. The chromium atoms forming the crystal give ruby its vibrant red colour and result in the light emitted from the laser to be of a similarly distinct deep red colour. As shown in Figure 1 below, the ruby laser contains a quartz flash tube, a cylindrical rod made up of ruby crystals and two mirrors at each end, one completely reflective and the other partially reflective. The flash tube is a high-intensity lamp spiraled around the ruby rod, where high-voltage electricity within the flash tube causes it to generate an intense burst of light that excites the atoms in the ruby crystal such that some of these atoms produce particles of light (photons) when they reach a high energy level. Through the process of stimulated emission, photons from one atom stimulate the emission of photons from other atoms and the light intensity is amplified. The mirrors placed at either end of the ruby rod reflect the photons back and forth, further stimulating the emission of photons and continuing the process of amplification. Eventually, the beam of light that leaves through the partially silvered mirror at one end of the ruby rod is known as laser light (“The first ruby laser”, n.d.).



Figure 1. Components of the first ruby laser
Reproduced from The First Ruby Laser. (n.d.)

The initial signs of laser’s growth to prominence can be traced back to early 1963 when Barron’s magazine estimated that the annual sales for the commercial laser market was likely to hit $1 million after lasers began appearing in the commercial market in 1961. This number is later seen to grow extensively as industry analysts predict that the global laser market will grow about 11 percent in 2010, with total revenue soaring to $5.9 billion (“History of the laser”, n.d.). Looking forward from historical perspectives, it is expected that the global market for lasers will grow further, reaching $8.8 billion in 2014 (“Recovery and new opportunities spur 9% growth in laser market”, n.d.). Although laser sales were punctuated by recession especially during the global economic recession of 2008/2009, the laser market has managed to recover its losses and record a steady upward growth by 2010. According to Overton, Anderson, Belforte and Hausken (2011), although the worldwide revenue earned from the laser market dropped by a shocking 23.5 percent from the $6.54 billion recorded in 2008, its recovery has been faster and more extensive than the predicted growth rate of 11 percent by 2010. In fact, laser sales increased by a sharp 27.3 percent from 2009 to 2010, neutralizing the 27 percent downturn witnessed during the recession and the demand for laser has been observed to be growing ever since.

3.        Current Situation
Since its invention, laser has evolved substantially, with modifications made and new variations introduced since the first working ruby laser paved the way for a growing laser market. Lasers are now perceived to be invaluable tools across a multitude of applications as a consequence of their extreme versatility, easily becoming one of the most significant innovations developed in the 20th century (“Lasers in our lives, 50 years of impact”, n.d.). The inception of laser technology with the introduction of the first laser can be described as “a solution looking for a problem” and this problem soon found grounds across a diverse range of sectors, including medicine, military and communications. Notably, a laser’s distinctive qualities such as its unique production of a narrow and intense beam of light that is able to travel in a specific direction without dispersing; has differentiated it from ordinary light and increased its value to the emerging demands and growing needs of the modern society (Garwin and Lincoln, 2003). As a result, laser has been successfully harnessed as an answer to challenges in the aforementioned sectors. Quoting Garwin and Lincoln (2003), “Today, lasers are everywhere: from research laboratories at the cutting edge of quantum physics to medical clinics, supermarket checkouts and the telephone network”. This is especially true as we enter a technological age, where turning to advanced tools for help to solve problems or improve the quality of life is becoming almost instinctive and this precisely explains the current situation where laser is seen to be both prevalent and prominent. Hence, this paper aims to examine the different types of laser used in the present day as means to solving problems faced in the three key sectors or as a revolutionary technology employed in these industries to improve the quality of mankind. The implications of laser on the health and safety of mankind will also be included in the discussion of the current situation within the laser market.
(i) Laser as it is today
In this paper, I will explore some of the current developments in laser that have been used to cater to the demands and needs of the identified industries in order to provide a better insight into the present situation within the laser market.
a)     Medicine

Laser medicine refers to the use of a variety of laser types in the process of a medical diagnosis, therapy or treatment (“Lasers in Medicine”, n.d.). Each laser operates within a very narrow wavelength range and emits a strong beam of coherent light that is capable of focusing on a very small point, enabling lasers to have a high power density aimed at a specific area (Harris, 2011). These special properties have given lasers an edge over sunlight or other light sources at targeting medical applications, which explains both the use of lasers in many areas of medical diagnosis and treatments (its prevalence), as well as the significant rise in the number of medical procedures carried out (its prominence) using this superior technology (“Advancements in Laser Technology Drives the Global Medical Laser Systems Market, According to a New Report by Global Industry Analysts, Inc.”, 2013).

Advancements in laser technology have generated a plethora of applications within the medical field, where some of the current developments include the use of laser in areas such as ophthalmology, oncology, cardiology, dermatology, dentistry, cosmetic surgery, diagnostics, gynecology, gastroenterology, and urology (“Advancements in Laser Technology Drives the Global Medical Laser Systems Market, According to a New Report by Global Industry Analysts, Inc.”, 2013). This report will serve to provide insights into the use of medical lasers in some of these areas highlighted.

1. Ophthalmology

Ophthalmology is the branch of medicine that is concerned with the study and treatment of disorders and diseases of the eye. Ophthalmology currently utilizes an imaging technique named Optical Coherence Tomography (OCT) that is able to give high-resolution, cross-sectional, and three-dimensional images of biological tissue in real time by making use of the coherent light emitted from a laser. This technology has allowed ophthalmologists to see a cross section of the cornea to diagnose retinal disease and glaucoma, demonstrating the importance of laser in medical applications. Beyond the use of OCT to diagnose problems related to our eyes, there has been much enthusiasm about its potential in other areas of medicine. According to Fujimoto, a co-inventor of this technology from the Massachusetts Institute of Technology (MIT), one of the major areas that is emerging for OCT is fiber optic imaging of arteries, where the harnessing of OCT as an imaging tool for observing heart vessels will create a breakthrough in the medical field as it gives cardiologists the unprecedented ability to see what they are doing (Harris, 2011).

The application of laser in ophthalmology is not merely limited to the diagnosis of possible complications in our eyes but also extends to the treatment of these complications. Laser-Assisted In Situ Keratomileusis (LASIK) is an example of how laser has been employed to treat refractive errors, improve vision and reduce or eliminate the need for spectacles or contact lenses. This procedure makes use of a highly specialized laser, the excimer laser, to alter the shape of the cornea, which is the transparent front covering of the eye that is responsible for the refraction of light and accounts for approximately two-thirds of the eye’s total optical power (Randleman, n.d.). LASIK involves the use of an instrument called a microkeratome to create a thin and circular flap in the cornea. The surgeon then proceeds to pull back the hinged flap to remove the underlying corneal tissue with the use of an excimer laser that generates a cool ultraviolet light beam to precisely ablate tissue from the cornea to reshape it. The flap is then repositioned and laid back into place, covering the area where the corneal tissue was removed. When the cornea is reshaped in the right way, it is able to better focus light into the eye and onto the retina, providing clearer vision and correcting refractive errors such as myopia and astigmatism (“LASIK technology to boost eye refractive surgeries in Kenya”, 2013). LASIK has been proven to be safe and effective for majority of the patients, with many advantages such as its ability to accurately correct most levels of myopia (nearsightedness), hyperopia (farsightedness) and astigmatism, with a fast procedure that usually lasts only 5 to 10 minutes and is generally painless. Moreover, since a computer guides the laser, the results are precise and accurate, with most patients requiring only a single treatment to achieve the desired outcome (Randleman, n.d.). As of 2010, over 20 million people worldwide have undergone LASIK surgery, making it one of the most common surgeries performed today, a phenomenon that would not have been possible without laser technology (“LASIK & Laser Eye Surgery”, 2013). The extensive use of laser in medicine and surgery is no wonder laser has grown to become a technology both prominent and prevalent in the medical field as it is harnessed both as a solution to the various health complications we have and as a tool to improve the quality of life for mankind.

2. Oncology

Oncology is the branch of medicine that deals with cancer through the study and treatment of tumours. Lasers play a major role in the early detection of cancer. The infrared (IR) laser, for example, is capitalized on for its potential in infrared spectroscopy, which deals with the infrared region of the electromagnetic spectrum. This is light with longer wavelength and lower frequency than visible light. IR lasers will thus be useful since cancer and healthy tissue may have different transmissions within the infrared range. Currently, researchers are exploring the application of IR laser in measuring melanomas and detecting skin cancer, where early diagnosis is vital to the survival rates of patients. The IR laser is tested in Israel during its annual free public melanoma screenings and it was proven to have enabled physicians to differentiate between benign marks and actual melanoma in patients suspected to have skin cancer (Harris, 2011).

Apart from its uses in the diagnosis of cancer, lasers are also increasingly used in the treatment of different types of cancer. This is because lasers are less damaging to the human body compared to X-ray therapies and surgeries. Lasers are highly effective in curing illnesses related to gynecology, ear, nose, throat, tongue, palate and cheeks, being curative in the early stages of cancer and valuable in reducing tumours to facilitate surgical procedures during the later stages of cancer. Currently, a new type of cancer treatment known as photodynamic therapy (POT) is introduced into the study of oncology that combines laser with light-sensitive dye or hematoporphyrin derivative (HPD). HPD comes from cow’s blood and is injected into the body of patients such that the substance settles in the malignant tissues. A red light from the argon pumped dye laser is then focused onto the area and proceeds to activate HPD, where the energized substance will then release a highly reactive chemical that destroys the cancer cells. Reports have shown that POT is 80 to 90 percent successful in resulting in the total or almost total regression of tumours, remaining effective even if other forms of therapy are exhausted and have failed. This technique is highly selective for a diseased tissue and leaves healthy cells relatively untouched, reducing the risk of utilizing this laser technology. Indeed, the use of lasers to remove cancerous growths or tumours in the body has heralded an era of knifeless and bloodless surgery in some cases, illustrating the importance of laser in the medical sector as a tool harnessed to provide solutions to the health problems that mankind faces (“Laser and its applications”, n.d.).

b)     Military

Currently, laser is also used for military purposes, where its applications in establishing defense and security are far-reaching and covers land, water and air protection. This exemplifies the prevalence and prominence of laser in the modern context where advanced technology is consistently being put to use to either address challenges or increase the quality of life. This paper will examine some of the uses of laser to enhance water and air prowess for the military to provide its people with greater safety and surveillance.

1.     Water: Underwater laser

Lasers are currently used for underwater transmission of signals. Previously, submarines have to depend on sonar to locate enemy vessels and to steer clear of objects underwater, which has severe limitations since marine animals like whales and dolphins can send false signals that leads to the sonar system being inaccurate in alerting the navy. Moreover, the sonar system cannot provide a well-defined picture since the sonar beam is scattered and spread out underwater, with the salt in seawater further causing the sonar beam to bend and create a wrong illusion that the target is appearing when it is not in reality. One other key consequence of using sonar is that it exposes the position of the craft to the enemy, hindering the navy’s ability to remain concealed when conducting their operations. In light of these problems, a superior technology needs to be introduced and this comes in the form of laser technology. Lasers are currently employed for effective ranging (the process of determining the distance between one position to another position) and detection of underwater objects or potential enemy targets. This is achieved with the use of a frequency doubled Nd:YAG laser, an argon ion gas laser or a Raman shifted xenon chloride laser. A schematic diagram of an underwater ranging and viewing system is shown in Figure 2 below. It consists of a laser transmitter, which sends high power laser pulses of about 10-nanosecond duration to the target at the rate of 30 to 50 per second through a beam splitter. After going through a diffuser, laser light that is reflected by the beam splitter is made to fall on the photodiode in the ranging and display circuit to start the time interval counter. The reflected light from the target is collected by telescopic optics after an interference filter eliminates stray radiation. A range gating circuit helps to avoid unwanted echoes. The reflected pulse from the target is intensified by the image intensifier and the output is sent to the image orthicon, which generates an image of the object. In this way, both the range and the image of the target are obtained. With high power release of several megawatts, underwater ranging is possible up to 500 meters in clear water. This allows the military to navigate underwater more effectively (“Laser and its applications”, n.d.). 

Figure 2. Schematic diagram of underwater ranging
Reproduced from Laser and Its Applications. (n.d.)

Other military uses of laser include underwater communication between submarines, where lasers are employed to build a guidance system with absolute privacy for torpedoes (self-propelled underwater missiles) and other unmanned underwater vehicles so that they are able to navigate without direct or continuous human control. Recent underwater laser communication has been established via satellite, from ground-to-satellite and then to underwater stations (“Laser and its applications”, n.d.).

1.     Air: Air Reconnaissance

Lasers are also used as secretive illuminators for high precision aerial reconnaissance especially in the night. Previously, this was achieved using a camera equipped with magnetic flares or powerful strobe lights but the power supplies were simply too cumbersome. Lasers, with their useful properties of having a narrow and intense beam of light, are thus sought after as an alternative to earlier technologies. A helium-neon laser or a gallium arsenide semiconductor laser is employed to provide air reconnaissance. The schematic diagram of the laser camera is shown in Figure 3. According to the diagram, light from a laser beam travels downwards through a six-sided prism scanner towards the surface of the Earth, where the prism will scan through a selected angle that is right angle to the direction of the flight of the aircraft. Another beam of light passes through a Pockels cell modulator and when it emerges from the modulator, the beam strikes the prism scanner and is then reflected and recorded on the film. The laser beams reflected from the target area are picked up by a Schmidt lens, which projects the light onto a photodetector. The video output of the photodetector corresponds to the reflectivity of the observed terrain and thus, drives the modulator. The returned beam then modulates the original beam. The images generated are similar to those captured under daylight conditions. Hence, this allows the military to photograph the movements of their enemy targets even at night under high secrecy during the flight of the aircraft. Currently, this laser system has been tested and proven to be a success by the United States Air Force Tactical Air Reconnaissance Centre, demonstrating the importance of laser technology even as a tool to aid in the operations of the military (“Laser and its applications”, n.d.). 

Figure 3. Schematic diagram of a laser camera
Reproduced from Laser and Its Applications. (n.d.)

a)     Communications

The current use of laser as means to transmit signals and send data has revolutionized the way we communicate, replacing conventional methods that make use of radio frequencies. The finite nature of the radio spectrum coupled with the insatiable appetite for these radio waves has made laser an even more useful technology in a world that increasingly demands faster and higher quality communication. The military is one major contributor to this phenomenon, especially with the introduction of unmanned aerial vehicles that requires the ability to transmit live, streaming videos to military bases around the globe. Moreover, this demand is postulated to increase with the proliferation of higher resolution sensors that feed on more bandwidth. In addition, overcrowded radio airwaves are susceptible to interference or illegal operations by opponents to jam signals and intercept messages. On the other hand, laser communications do not make use of the radio spectrum, which eliminates the problems and limitations of using radio waves (Magnuson, 2013). A particular aspect of laser transmission that makes it preferable to the ordinary radio waves is the strict secrecy enabled by the narrow beam width of laser light. A high level of secrecy is preserved between two points because no unwanted reception outside the narrow rays emitted from the laser is able to pass through and hence, an interception-proof communication network can be brought to fruition (“Laser and its applications”, n.d.). This is especially useful in the area of communication for military purposes since adversaries have to first detect the narrow laser beam and then place an object in front of the ray in order to disrupt the transmission. Furthermore, to intercept the data sent, a receiver has to be positioned in the path of the laser beam, all of which are difficult to do especially without detection (Magnuson, 2013).  Moreover, a laser communication system is immune from jamming and from interference by spurious radio noise, which makes it an even more effective technology in facilitating communication (“Laser and its applications”, n.d.).

Laser communication can also be harnessed for space purposes. While radio-based space communications are used typically, current advancements in laser technology can revolutionize the way we send and receive signals, video, images and other data since lasers are able to transmit data at a speed 10 to 100 times more efficiently than radio frequencies while consuming conspicuously lesser power. In addition, the shorter wavelength of lasers ensures that energy is not unnecessarily dispersed as the light travels through space. A conventional Ka-band (A component of the K band within the microwave band under the electromagnetic spectrum) signal from Mars, for example, is dispersed excessively such that the diameter of the energy when Earth receives it is of a magnitude greater than the Earth’s diameter. A signal sent by a laser however, disperses over a smaller area (the distance across a small part of America) and thus, wastes less energy. Moreover, shorter wavelengths allow for significantly more bandwidth compared to radio frequencies, where radio waves have to fight over a limited and finite bandwidth. Currently, invisible and near-infrared lasers are tested for the purpose of sending data to and from the satellite and the NASA team is working towards developing a stable, efficient and cost-effective optical laser communication technology (“Technology Demonstration Missions: Laser Communications Relay Demonstration (LCRD)”, 2013).

(ii) Laser and its implications
While laser has brought about a string of benefits for mankind, it would be over-ambitious to assume that it is without its shortcomings. Laser technology has multiple risks attached to it, and can potentially cause complications despite it being deemed as a relatively safe instrument to wield (“Risks from lasers”, n.d.). This paper will analyze some of the impacts of laser on health and safety to provide a more holistic understanding of not merely the benefits but also the possible dangers and consequences of utilizing this tool. This knowledge is especially important in light of the growing prevalence and prominence of laser in an advanced and technologically reliant society as the one we currently reside in, as it ensures that we reduce the chances of having asymmetrical and imperfect information of the technologies that we make use of.

1.     Impact of laser on health (Risk of laser in surgery)

Lasers used for the purpose of surgery can have negative impacts on our health. This is because all medical procedures including laser treatments expose patients to varying degrees of risk and complications. While we can minimize the extent of the risks involved, it is nearly impossible to completely eliminate the dangers attached to medical operations. Hence, it is prudent that patients are informed about the potential hazards before undergoing laser surgery. Similarly, medical practitioners should attain a good knowledge of the implications of laser and its causes to better manage and prevent these complications from occurring (“Risks from lasers”, n.d.). Hence, this paper will examine the risks involved in laser surgery to demonstrate the impact of laser on our health.

a)     Risks of laser eye surgery

According to the Royal College of Ophthalmologists, severe complications as a result of laser eye surgery are rare with negative side effects arising in less than 5% of patients undergoing this treatment and chances of extreme implications such as blindness occurring being almost completely absent (“What are the risks of laser eye surgery?”, n.d.). However, this does not nullify the existence of risks and complications involved. Some of these risks include the possibility of impaired night vision after the laser eye surgery, which makes it difficult for the patient to see under dark conditions. As a result, glares, haloes or double visions may occur that can cause sight to be uncomfortable for these affected patients. This is because the surgery can reduce the patient’s vision under dim light even though a positive visual result is recorded under standard testing conditions after the laser eye surgery is completed (“LASIK eye surgery: Risks”, 2011).

Apart from that, corneal flap complications can arise as a consequence of laser eye surgery. These problems surface in the process of removing or folding back the flap during the surgery (“LASIK eye surgery: Risks”, 2011). A slipped corneal flap, which is a flap that becomes detached from the rest of the cornea, is a common complication that occurs after the surgery. While the chances of corneal flap dislocations are reported to be highest immediately after the surgery, late dislodging of the corneal flap is not unusual and can occur 1 to 7 years after the surgery (“LASIK complications”, n.d.). In-growing cells is another laser surgery risk that occurs when trapped debris causes cells to grow underneath the corneal flap (“What are the risks of laser eye surgery?”, n.d.). Epithelium, the outermost corneal tissue layer, ends up growing abnormally under the flap (“LASIK eye surgery: Risks”, 2011) in a symptom called epithelial in-growth (“LASIK complications”, n.d.), which can develop into a sight-threatening complication that leads to the patient having to risk the probability of visual impairment (“Epithelial Ingrowth”, n.d.). 

Laser eye surgery also hinders with tear production and thus, patients might face with exceptionally dry eyes during the post-surgery period (“LASIK eye surgery: Risks”, 2011). Dry eyes are accompanied by stinging or burning sensations that are painful and can affect the quality of vision, with the bad news being that this negative side effect is among one of the most common risks of laser eye surgery (“What are the risks of laser eye surgery?”, n.d.).  Moreover, in extreme cases, severely dry eyes can occur and cause permanent chronic pain or even blindness especially when it is left untreated (“LASIK complications”, n.d.). Thus, it is vital that patients get sufficient information about the risks of using such a technology especially if they are prone to conditions like dry eyes that can worsen after the surgery is conducted (“What are the risks of laser eye surgery?”, n.d.).

b)     Risks of laser skin surgery

Aggressive advertising has culminated in a century centered on the pursuit of beauty and youth. The advent of cosmetic laser technology has fueled this obsession with smoother, fairer, younger and more radiant skin. However, many are unaware of the resultant complications that can arise as a result of such dermatologic laser surgery. My paper explores some of these risks to bring to light the potential negative implications of using laser.

One of the epidermal complications that can arise as a result of dermatologic laser surgery is postoperative blistering, which is the formation of blisters or vesiculation due to epidermal thermal damage. This negative side effect can develop from all laser systems used in laser skin surgery and is typically witnessed from the use of Q-switched laser irradiation for tattoo removal. Some reasons for the development of this complication include the use of too much laser fluence (a stream of laser particles) or the unintentional absorption of laser energy due to the increased presence of an epidermal chromophore (an atom or a group of atoms responsible for the colour of a compound) such as melanin in a tan. (Brown, 2012).

One of the dermal complications that occur following laser skin surgery is scarring. This is among one of the most feared negative implications due to its long-lasting and near-permanent nature. Scarring results from direct laser-induced thermal damage or from complications such as postoperative infection that leads to excess damage to the collagen comprising the dermis. Cutaneous laser resurfacing has the highest risk of causing scarring due to the deliberate destruction of dermal tissue and the increased risk of infection occurring in the de-epithelialised skin. Moreover, since every individual’s skin has different levels of receptiveness towards such laser treatments, it is difficult for a surgeon to predict the implications of laser skin surgery and thus, the risk of such complications are still existent despite being operated on by the best and most well-trained surgeons (Brown, 2012).

2.     Impact of laser on safety (Risk of laser on aviation safety)

Laser light can be harnessed for multiple purposes across a diverse range of sectors as described in the above section on the current uses of laser. In this segment, however, the paper will explore a different side of laser light as it serves to highlight the potential risks attached to utilizing laser technology, with the focus placed on safety considerations in the area of aviation.

Lasers are aimed at airspace for various reasons that differ from entertainment in the form of laser pointers or outdoor shows, to research in fields like astronomy. Lasers are even used to shine at aircrafts to warn pilots that they are straying into unauthorized air spaces. For the purpose of this research paper, I will narrow down on the risks associated with the use of lasers that affect aviation safety. Laser light can be hazardous when it is directed at aircrafts. In United States, it has been reported that the number of incidents of lasers being directed at its aircraft has exceeded 2,800 since 2004, raising concerns towards the misuse of lasers aimed into airspace as they create dangerous flight conditions for pilots, endangering the lives of those on board the plane (“Laser safety”, 2013). This happens when the sudden and unexpected burst of bright visible light causes distraction to the pilot and result in them feeling unsettled. Moreover, as the brightness of the light intensifies, it can interfere with a pilot’s vision due to the glare from the laser light that makes it arduous to see out the windscreen. A pilot’s night vision might be shrouded and this can disrupt the smooth proceedings of a flight operation. Laser light can even lead to temporary flash blindness for the pilot that incapacitates a pilot’s ability to see clearly and stimulates the appearance of afterimages that leaves temporary spots in the pilot’s vision. These negative side effects can lead to severe consequences if the pilot is unable to recover his sight on time as it jeopardizes the safety of the crew and passengers on board the plane especially during critical phases such as takeoff, landing and emergency maneuvers. While such cases are rare, the danger of lasers causing eye damage is not entirely mitigated. High power laser light is capable of leading to permanent eye injury. This injury varies in its severity depending on the precision and intensity of the laser light shone on the aircraft. In extreme cases, such eye damages as a result of the bright light emitted from a laser can induce a state of complete and permanent loss of vision (“Lasers and aviation safety”, 2013).

Bearing in mind the implications stemming from the various applications of laser, it is prudent that users of laser are aware of the risks involved so that they can form more informed decisions before wielding this technology. This is especially important since laser is becoming increasingly prevalent and prominent as proven in this paper, which leads to the consequences being amplified and the urgency to manage these risks and fears being elevated. Thus, this leads to the need for the subsequent section on the future considerations of laser technology.

4.        Future Considerations
This section of the paper explores the future considerations pertaining to the use of laser technology. It will examine how risks and fears perceived can be better managed through the introduction of counteractive measures, and predict the future of laser technology to assess the sustainability of laser as a prevalent and prominent tool.
(i) Management of risks and fears
In light of the various risks brought about by the applications of laser as discussed above, it is beneficial to introduce the possible measures that can be taken to manage these risks so as to allay fears that some might bear towards the use of this technology.
a)    Management of fears towards the risks of laser in surgery

Risks and fears towards the use of laser in surgery can be managed by following a set of guidelines. This includes a comprehensive understanding of the dangers involved especially in the case of a laser eye surgery that serves the purpose of correcting an individual’s vision, which is considered an optional surgery since it does not pose a grave threat to the patient’s health and well being (“LASIK eye surgery: How you prepare”, 2011). As addressed above, patients with dry eyes and other eye conditions such as keratoconus (a cornea condition) or health problems such as HIV or other immunodeficiency conditions should particularly factor in the possibility of an increased risk when undergoing the treatment and the chances of laser aggravating their existing problems in the case of dry eyes (“LASIK eye surgery: Risks”, 2011). This similarly applies to laser skin surgery since laser treatment might not be suitable for sensitive skin and inflamed or broken skin. Thus, it is important to undergo laser operations only after detailed consultations under a registered practitioner so that the patient’s suitability is fully evaluated and advised before the commencement of the treatment (“Laser treatment”, 2012).

Post-surgery measures can also be undertaken to reduce the risk of complications arising and speed up the healing process. For laser eye surgeries, risks of negative implications can be lowered if patients regularly attend post-surgery examinations that monitor the recovery of the operated eye and ensures the optical health of the patient. Patients also need to follow through with post-surgery care by adhering to the regimen of eye drops, protective eyewear especially under glaring lights and other procedures recommended by the physician to better manage the risks of negative side-effects occurring (“After laser eye surgery – Post LASIK care”, n.d.).

b)    Management of fears towards the risks of laser on aviation safety

Similarly, there is a range of measures that can be taken to reduce the potential risks of laser on the safety of aviation. This includes enforcement, where police officers are mobilized on aerial vehicles like helicopters to patrol and identify culprits that are misusing laser to aim into airspace and disrupt the smooth proceedings of aircrafts. Hazard reduction measures can also be employed to manage the risks of laser accordingly. Examples of such methods include the termination of laser beams on structures like buildings or trees during outdoor laser shows for entertainment as mentioned in the section above. This would prevent the laser beam from trespassing protected airspace and interfere with aviation safety. Another hazard-reduction measure that aims to minimize risks is through the development and compliance of policies for outdoor laser operations like that of National Aeronautics and Space Administration’s (NASA) “Use Policy for Outdoor Lasers” and American National Standards Institute (ANSI) standard “Safe Use of Lasers Outdoors”. Regulatory measures such as the implementation of bans that restrict the use or sale of lasers can aid in the management of risk of laser light being shone inappropriately on aircrafts. Countries can follow the footsteps of Australia who imposed legal regulations on the purchase, storage and utilization of laser pointers in 2008. Pilots and crew can also undergo training to receive knowledge on the procedures towards quicker recovery in the event of laser illumination. Articles with the likes of “Laser Illuminations: The Last Line of Defense – The Pilot!” have also been published in aviation magazines to provide more information on the management of risks associated with laser beams. Lastly, active hazard-reduction measures can be considered when dealing with the negative implications of laser on aviation safety. These measures introduce protective eyewear such as laser safety goggles to shield pilot from the bright light emitted from a laser. Advancements in technology have allowed for the creation of smart goggles that are capable of detecting laser light and stimulate a blockage or dimming system according to the wavelength and intensity of the laser beam. Glare shields that work like windscreen filters can also be used to minimize any incoming laser light. These methods can serve to reduce the consequences of laser incidents and thus, effectively manage the risks of laser on aviation safety (“Lasers and aviation safety”, 2013).

(ii) Laser in the future
The advent of lasers in the 1950s has allowed for Man’s dream of possessing this useful and powerful technology to materialize and its development since then has seen laser being incorporated within our daily lives, as an important and transformational tool of both prevalence and prominence (Noticewala, 2011). From surgery and medical diagnostics to laser equipments for warfare and defence, lasers are employed in virtually every facet of our lives (“Laser Innovation: Why The Next 50 Years Look Even Brighter”, n.d.). However, future developments of laser are still unknown, with the continued sustainability of laser’s pervasiveness and preeminence being an open question to many. Hence, this paper aims to study the situation of laser in the future. Moving away from historical perspectives and the current situation, this section serves to provide a shift in focus towards the potential areas of growth in the market of laser, which has been forecasted to carry great promise in all the identified industries that will be covered in detail below. This is especially so as the laser’s capability is now improving in leaps and bounds with the use of science and technology to manipulate the almost infinite combinations of pulse durations, pulse shapes, wavelengths and power levels of laser that will exponentially increase the potential applications of laser (“Laser Innovation: Why The Next 50 Years Look Even Brighter”, n.d.).

a)    Medicine

According to researchers, laser technology will be harnessed to create new alternatives to conventional biomedical practices. For instance, lasers are extremely beneficial as tools to aid in medical diagnosis because their useful properties allow for non-invasive probing of tissue (Noticewala, 2011). In the diagnosis of cancer, a biopsy is typically needed to confirm the nature of the lump detected so as to ascertain if the growth is cancerous. However, such conventional methods are usually time-consuming and so, lasers are employed instead to develop faster and better diagnostic techniques to identify cancerous cells. A laser-based sensor is developed for future applications to aid in tumour detection by making use of a transmitting fiber to transfer laser light to a microscanner mirror positioned at the end of the endoscope, which deflects the laser beam and illuminate the identified tissue. An 8-millimeter-diameter micro-electro-mechanical system (MEMS) microscope head is fixed into the laser-based sensor, where it will serve to magnify tissue cells measuring merely 10-20 micrometers that are too small to be seen by the human eye. In this way, this laser-based sensor can be used for future cancer diagnosis, potentially eliminating the need to undergo biopsy (“Lasers deliver a bright future for diagnostics”, 2010). The recent creation of a handheld laser scanner also carries great potential in improving the future medical scene as it aims to enhance the efficiency of breast cancer diagnosis. The laser scanner produces a spectral “fingerprint” of patients to evaluate if the breast tumours developed need more intensive treatments. This device generates comprehensive breakdowns of the amount of hemoglobin, water and fat content, tissue density and oxygen consumption by the tumour to allow medical practitioners to attain more precise information on the effects of chemotherapy on cancer cells, and thus determine the necessary treatments more accurately. This is a function exclusive to the use of laser that the traditional mammogram is unable to replicate. Taking into consideration the gray areas in the contemporary use of the mammogram for breast cancer detection, this new laser equipment aims to minimize the flaws associated with present technologies to improve the quality of diagnosis procedures. This laser scanning method, for example, can improve detection of breast cancer in younger women whose breast tissue are denser and are hence, less sensitive to the mechanisms of a mammogram. While the innovation is still under evaluation, it has definitely brought hope to the advancement of medical diagnosis that is pivotal as the first step to the treatment of potential health problems faced by mankind in the future (“Lasers deliver a bright future for diagnostics”, 2010).

Apart from the uses of laser in medical diagnosis, lasers also carry the potential in serving as the future of addiction therapy. Researchers are looking into harnessing laser light as solutions to stamp out addictive behaviours. Addictions to drugs such as cocaine are becoming one of the major health concerns especially in countries like America, where approximately 1.2 million people are affected by cocaine addictions and annual emergency room visits as a result of cocaine usage are as high as 482,188. A cocaine addiction occurs when victims consume the drug compulsively and end up losing the ability to function without it, resulting in the constant abuse of this drug. It has been reported that approximately 80 percent of the people who attempt to kick off the habit end up experiencing a relapse within a short duration of six months, demonstrating the ineffectiveness of present therapies in getting rid of cocaine addiction. This is where laser can be employed to curb the addiction, possibly in the future. Experiments are currently being conducted to measure the impact that laser has on the brain activity of lab rats that were addicted to cocaine. Since cocaine has been found to cause low levels of activity in the prefrontal cortex, clouding one’s ability for behavioural flexibility and decision-making, laser light is aimed at this region of the brain to test its effectiveness in reducing addictions. The results of these experiments reveal that laser can activate the nerve cells in the prefrontal cortex, where this newfound ability is proven to greatly reduce addictive behaviours, providing mankind with a breakthrough in the use of lasers for future applications in the medical sector (Nordqvist, 2013).

b)    Military

The prominence of laser in the future is not merely exemplified by the potential applications of laser technology in the medical sector but is also proven by its expected use to improve military prowess in years to come. In America, for example, the navy is expected to deploy lasers in ships by the year 2014. This will give its military powerful cutting-edge weaponry, as the ship-mounted laser is believed to be able to decimate small boats in the water and unmanned aerial vehicles with the infrared energy emitted. The effectiveness of this laser equipment has been tested and an unmanned drone was seen to burst into flames after the laser was aimed at it. The laser’s ability to ignite and burn targets without the hassle of having to replace the magazine like that in typical firearms can be very useful in future military applications especially as America can now use this superior technology to attack the drones utilized by Iran to surround and harass the Navy’s ships. These lasers have a hundred percent success rate in exterminating targets and possess several additional advantages such as a relatively low cost of operating it ($1 per laser shot) and the flexibility of the laser to have non-threatening functions alongside its lethal capacities, which enables it to be used as means to send warning signals to other vessels alongside its main purpose. Laser weapons are described as the future of national defence and warfare, and similar laser weapons are constantly being developed such as the FEL (free electron laser) that is tested to be capable of burning and destroying feet of raw steel, with a power range that is adjustable according to weather conditions. This provides the military with an even more flexible weapon. While these laser-based innovations are not released in the market yet, it is safe to conclude that laser is here to stay (Fishel, 2013).

5.        Conclusion
In conclusion, this paper serves to demonstrate the progress of laser technology from its initial inception as a mere concept to its current state of prevalence and prominence. The birth of the first ruby laser in 1960 has snowballed into the multiple applications of laser across different industries such as medicine and surgery, military and communications. Present day uses of laser include laser in oncology, lasers for air reconnaissance and lasers to improve the efficiency and speed of communication, all of which have served to revolutionize the way we live as lasers offer viable and valuable solutions to the challenges we face in our daily chores and have been employed to improve the quality of life for mankind. Nevertheless, it is apt to recognize the limitations of using this technology. Laser carries risks that can endanger our health and safety, which would thus require counteractive measures to manage these negative implications and minimize the adverse impacts of laser. With the availability of a diverse range of methods to manage these risks, the future of laser technology is enhanced especially as new and more cutting-edge lasers are increasingly being materialized with advancements in science and technology that has ensured the sustainability of laser’s prevalence and prominence even in the future.

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[1] This paper is reviewed by Clara Chu and Zhuang Lingzhen.

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