PointerLaser Review: May 2011

Tuesday 31 May 2011

Military Lasers & Law Enforcement

In use by many governments all over the world, military lasers are often used to dazzle the enemy on the battlefield. Military lasers have a range of uses. One key application is to confuse and suppress enemy insurgents through shining exotic ultra high-powered army lasers.

Warn Lasers offer ultra high-powered solutions for RECON, CSAR, Urban-Warfare as used by special weapons and tactical response teams. Our lasers are used by military forces around the world as divergent capable dazzlers, target painting and distraction devices among other uses.

Army & Military Lasers have become an indispensable part of the arsenal used to combat bad guys on the battlefield, on the street or wherever they may slither and hide.

Its no mystery that many military organizations throughout the globe incorporate the use of various laser devices into their entourage of weapon systems. It seems the value and versatility of high power lasers has worked its way beyond contemporary science and astronomy, we now see laser pointers and other powerful laser devices at the forefront of the modern day battle field. There are many clear combat advantages military laser pointers provide to today's foot soldier. Whether mounting the laser diode as a laser sight, or a high power laser pointer for pointing out enemy locations, or even underwater reconnaissance, there is no more useful tool than a military laser pointer.

It makes good sense to provide funding to military personnel for standard issue military lasers, not only as a weapon, but also as a life saving device. Many times a high power laser pointer is the only "homing beacon" a platoon or squadron can rely on to be retrieved during a gunfight or a failed operation. A high power laser beam is clearly visible through daylight and the night sky, and the most popular military laser pointer in production produces a powerful green laser beam at a light frequency of 532nm. This is because the military finds the greatest use in the brightest laser color possible to the human eye, the green laser beam. Many military lasers are so powerful that they can actual light a fuse, temporarily blind an enemy, burn, and ignite, making them great for protection and intimidation.

There is, however, a bit of controversy surrounding the availability of military laser pointers on the open market through online shopping sources. The debate is that extremely powerful laser pens, which can be considered dangerous, are too easy to purchase and use despite clear health and safety hazards that they create for un-trained users. The problem is that many people were taking advantage of military grade technology from the comfort of their own home, receiving wonderfully packaged powerful laser pointers to their front doors. To some, this may seem harmless, but the media has created a shroud of fear surrounding the concept of laser pointers, most especially, high power military lasers. When news hit the nation that a laser pointer had been used to blind a pilot on his descent to land his filled aircraft on an international air strip, immediate action was demanded by the public from both the FDA and Home Land Security. The unfortunate truth was that the laser pointer that was actually used was a low power 5mw green laser pen, not your average high power military laser pointer. Despite this knowledge, leaps and bounds were made extremely quickly to keep powerful military lasers out of the homes of your average civilian.

But laser hobbyists around the world have not backed down at all, in fact, laser sales worldwide have steadily increased year to year since the wide scale release of the green laser pointer at the dawn of the millennium. More powerful military laser pointers are being sold today than ever before. But there is some difference surrounding the laser pointer scenario currently. It seems that your average laser pointer enthusiast has gotten smarter and is now taking standard safety precautions when using their powerful lasers. Simple things really, such as not aiming the laser at any person, animal, vehicle, or building. Things that really anyone with a little common sense should be able to grasp, but when you are holding a powerful laser pointer capable of blazing a beam of light over 65 miles, its easy to get carried away. The military will continue to use laser pointers, and laser providers around the globe will continue to provide military laser pointers to laser users as long as the desire for more power exists.

Practical Laser Uses

Our average Warn Laser customer is a laser hobbyist who wants a laser to use for entertainment. Don't be mistaken though, Warn Lasers have many legitimate practical uses including some of the following:

Military and Law Enforcement: Lasers are used by US forces in Iraq to paint (identify) targets and intimidate the enemy. Military professionals prefer Warn Lasers to typical laser dazzlers for its sheer power and performance in a size that is similar to a ballpoint pen case.

Astronomy: Because warn lasers are strong enough to see a beam of light, they are ideal for pointing out star constellations. The next time someone tries to show you Orion's belt or Zeus in the stars, hand them the Warn Laser and make them trace it out. They can even be velcro mounted to a telescope to help you aim better.

Search and Rescue: They are a highly visible flare that can be used over and over again; here they represent the power to save a life.

Outdoor Work Sites: Warn lasers can also be useful at outdoor work sites. Construction managers use lasers to align pipes, walls, signs or any piece of construction material. Write with light and guide others with precision.

PC Shops: Shops that require fiber optical maintenance tools, will appreciate the additional power to find fiber interruptions and line breaks in fiber optic technologies with lasers.

Arts and Entertainment: Used on CSI: NY, in laser shows and to illuminate artwork, Warn Lasers command attention and ignite imaginations.

Physics Labs: Students take notice when a teacher uses a laser with power far beyond anything they can buy in an office supply store.

Medical: Since 1967, healthcare professionals have used lasers to reduce pain and speed healing. [WARNING: Warn Lasers are not FDA approved for medical use in the US].

Other Uses: From dispersing birds and other animal intruders to identifying fiber optic circuits, uses for Warn Lasers products are limited only by your imagination.

Medical Applications

532nm wavelength lasers have been used in medical research and development since the late 1960's. Medical lasers are in use worldwide and have contributed to countless successful surgeries and procedures. While Warn Lasers products are not directly designed for medical use, the 532nm wavelength is a very important part of the medical community and offers a wide range of applications.

Class IIIb lasers have long been licensed for medical use. Several medical professionals, including a chiropractor, who for various reasons prefer to remain anonymous, have been experimenting successfully with our lasers in the US. Read their testimonials below.

Relief of Chronic Pain and Swelling
"One patient of mine suffered a severe fracture of the left ankle five years ago. Surgical stabilization was required, using metal plates and screws. Ever since, this patient has suffered chronic pain, swelling, and the inability to walk properly. I used a 5mW laser on the ankle. One week later, he told me with amazement that his ankle pain was markedly diminished as well as the swelling (which was clearly visible). He even walked with less hesitation. I now use the 55mW on the ankle and it continues to respond favorably. The same can be said (again using your 55mW laser) for a 68-year-old female patient with tennis-ball-sized-swelling of an ankle, the result of altered venous drainage due to an old fracture of the tibia. The swelling was reduced to half after just one therapy laser session."

The Treatment
"I contact the edematous tissue (area of swelling) directly with the laser head and move the laser over the affected area at a speed of approximately 1 inch/second. For example, treating the ankle edema (swelling) would take approximately one and a half minutes."

Lasers in Medicine
First used in 1967, medical use of lasers is now common for increasing the speed, quality and tensile strength of tissue repair; relieving pain and inflammation; improving function of damaged neurological tissue and they are often used as an alternative to needles for acupuncture.

Why It Works
"There are several external stimuli that speed up the production of ATP (see sidebar), which is used in cellular/tissue respiration. In addition to lasers, these include ultrasound and electrical stimulation. Having used red lasers since the early 1980s, I now believe that I am getting better results with the green (532 nm) laser purchased from Warn Lasers.

I believe there are two factors making the green light superior: 1) the green beam is more energetic, producing additional heat, which is known to be beneficial. 2) The color green itself has a positive life-enhancing effect, associated with photosynthesis and lush environments. Like photosynthesis, the correct wavelengths and power of light at certain intensities for an appropriate period of time can increase ATP production.

The cell membrane could also be affected to improve permeability and second messenger activities that improve secretion and mobility. An appropriate dose of laser light can improve speed and quality of acute and chronic wound healing, soft tissue healing, pain relief and nerve regeneration, and also improve the immune system.

Applications include treatment of venous ulcers, diabetic ulcers, osteoarthritis, tendonitis, post herpetic neuralgia (PHN, shingles) and postoperative pain. Your laser really is a remarkable tool! I have been a practicing chiropractor since 1977 and have used just about every therapeutic "bell and whistle" invented. This medical lasers (532nm) beats them all in terms of pain and swelling reduction."

Sports Injuries
The most popular medical use of lasers is for treating sports injuries. Many of the world's elite athletes use laser therapy to speed their recovery because:
1. There is more published clinical and physiological evidence supporting the use of laser and LED photobiomodulation for soft tissue injuries and joint conditions than any electrotherapy modality as traditionally used by physicians and physiotherapists.
2. It's considered the safest "electrotherapy" available by research experts.
3. It's quick and simple to apply.
4. It can be used immediately after injury, over pins, plates and bony prominences.

Adenosine Triphosphate (ATP)
"I contact the edematous tissue (area of swelling) directly with the laser head and move the medical laser over the affected area at a speed of approximately 1 inch/second. For example, treating the ankle edema (swelling) would take approximately one and a half minutes."

Acupuncture Substitute
The same Chiropractor told us: "I also perform traditional needle acupuncture and have tried using the green laser for stimulation of acupuncture points. The Warn Lasers product is tolerated by patients better and is just, if not more, effective."

A Plea to the Medical Laser Community
Unfortunately, this laser is not FDA approved for medical use in the US. Physicians in many other countries are not so restrained. This type of treatment may be of particular interest to the Chinese medical community, which uses procedures such as acupuncture anesthesia for surgery and other procedures that are considered "alternative medicine" in the US, and are accepted only reluctantly.

Q-Switched Lasers

lasers which emit optical pulses, relying on the method of Q switching. Q-switching , also known as giant pulse formation, is a technique by which a laser can be made to produce a pulsed output beam. A Q-switched laser is a laser to which the technique of active or passive Q switching is applied, so that it emits energetic pulses . Typical applications of such lasers are material processing (e.g. cutting, drilling, laser marking ), pumping nonlinear frequency conversion devices, range finding , and remote sensing. That's because Q-Switched lasers provide high energy, high peak power pulses at high repetition rates. As Q - switching combines both short and long pulses. So it can also be used as medical area. For example, laser surgery such as tattoo removal, pigmented lesions and hair removal applications.

Now we have Q-switched diode-pumped green lasers, it's using rapid, high pulsed Q- Switched technology. More than a decade ago, Q-Switched Alexandrite laser was introduced operating at a wavelength of 755nm. These lasers have become highly proficient tools for the skin care professionals and dermatologist. In recent years, Q-switched lasers are also used at measurement purposes by measuring the time it takes for the pulse to get to some target and the reflected light arriving.

The operation of a normal Q-switched laser is like this. In the resonator, blocking one of the mirrors with a modulator ( the Q-switch ). The energy gets no way to go but build up and cumulate until the modulator switched on. Then a few spontaneous photons quickly stimulate the laser to emit all the stored energy in a giant, Q-switched pulse. The duration of pulse is depends on resonator's length, output coupling , the repetition rate and the pump power, etc.

UV Lasers/Ultraviolet Lasers (violet laser )

A violet laser has a wavelength bordering those of ultra-violet. Because the definition of ultra-violet is not clearly established, some people might call this a violet laser while others call it an ultra-violet laser.Actually,the wavelengths of violet light is 405nm. Yet other people call then Blu-ray lasers or HD-DVD lasers depending on the source and/or optical output of the diode. Usually a HD-DVD diode is incorrectly called a Blu-ray diode because it has became a commonly accepted term for the diodes of this color.

Ultraviolet laser products have many usage in scientific research, manufacturing, biotechnology and medical area. As we all know, the wavelength of Ultraviolet has characters of sterilization and disinfectant as lasers in the UV range have very destructive capabilities. The technology used in emitting Ultraviolet laser in laser pointers is very like micro-machining applications which often used in the manufacturing of printed circuit boards and consumer electronics.

Except the usage we talked at previous paragraph , UV lasers are also be used at OEM applications and other projects that require micro-precision machining. For example, in cosmetic dentistry UV lasers mainly used to facilitate chemical bonding and bleaching of organic enamels and other procedures. And also UV lasers are capable of performing experiments in atomic and molecular spectroscopy and chemical dynamics. Wavelengths emitted by UV lasers is shorter than blue lasers. So it's capable of producing 20 times as dense as the current Blu-ray lasers. In Japan, computer hardware manufacturers put UV lasers and ultraviolet diode emitters into computer data storage disk technology to increasing data storage capabilities drastically.

Now human beings spread Ultraviolet laser technology to a new generation of application in nanotechnology, material sciences, biology, chemistry, plasma physics and a myriad of other usages. Therefore, UV lasers become more and more important in humanal improvement.

Yellow Lasers - the color of the sun

Have you seen the yellow laser beam? It's amber. The wavelengths of yellow light is 589nm ~ 594nm. Because of its beautiful effect, yellow light laser pointer is produced. Yellow lasers are produced using the similar principles as green lasers which is pumping IR laser diodes into crystal and optical arrays to achieve a broader range of special lasing.

Yellow pointers appeared in laser market very currently. That means the technology about portable laser pointer format updates frequently. With the time goes, new technologies and innovations become more and more mature. Now laser enthusiasts don't need to pay lots to enjoy ambers and yellows beam. ( the color of the sun ) The amazing yellow wavelength is example how laser pointers can bring the nature to your life. And it's also your new choice of spectrums into your collection.

The birth of yellow laser beams and its industry are milestones to the achievement of laser history. As lasing technology improve, colorful laser beams are easy to get and affordable. Later,yellow lasers will migrate from diode pumped crystal arrays. I hope new lasing technology can make laser beams higher stability, increase output and longer laser diode life. Solid state diode can negate the need for MCA/ MOA configurations. No doubt yellow laser pointers will improve and time will tell how it can become to stand by along the key chain laser pointers.

Measuring Laser Power

It is often important to determine laser power output levels, and the optimal way to do this is by using accurately calibrated laser power meters. There are a number of laser power meters available commercially, but if you can’t justify the cost for one, you might consider building your own, via methods described in the repair FAQ page. If you only need to determine which of two lasers (of the same wavelength) is most powerful, or whether a laser power modification has made any changes, you can get some idea by using a silicon solar cell hooked to a volt meter. The meter readings will only be comparative, and will give no indication of the actual laser power, but even this might be better than knowing nothing at all. Any kind or size of silicon photovoltaic cell should do for this purpose. Just cover its entire surface with some opaque material, leaving only a small opening for the laser beam to shine through. Hook a voltmeter to the leads from the solar cell, put on your laser goggles, and fire away. Here are some links related to power meters and measurement:

http://www.coherent.com/Lasers/index.cfm?fuseaction=show.page&id=250&loc=830
http://www.repairfaq.org/sam/laserioi.htm#ioilpm3

When instrumentation is not available, some idea of a laser’s output power may be gleaned by doing simple tests, such as popping balloons, lighting matches, or cutting electrical tape and comparing the results with those produced by lasers of known power levels. When reporting the results of such simple tests, it does little good to state that a laser will pop a balloon at a given distance without clearly specifying the voltage powering the laser, the distance from the laser’s lens to the focal point of the laser beam, the exact characteristics of the target, and so on.

In order for laser users to gain understanding about such things as power levels, it is important that those who post reports on various laser forums carefully document their experiments and results. Here are some suggestions of how to inexpensively do this:

A -- Accurate volt meters are readily available and fairly inexpensive. Always tell the total voltage powering a laser module, because the laser’s output power can be greatly affected by the voltage of its power supply. An ammeter is also useful in order to measure the current being drawn by the module. When using laser modules powered by batteries, it is good to record the battery voltage both before and after the experiment has been conducted.
B -- Accurate thermometers are readily available and inexpensive. Always tell the approximate temperature of the environment in which the laser is being used. Laser diodes put out less power as their temperature increases, so it is important to have some idea of what the ambient temperature is, in order to make accurate comparisons.
C -- In lasers with beams that have been focused, instead of collimated, always tell the distance of the beam’s focal point from the end of the laser’s lens. There are a number of ways to quickly determine this distance.

If the focal point is very close to the laser, one can often see this point by viewing the beam in a darkened area, particularly if the air contains some smoke or moisture. Viewing the beam as it passes through a block of clear plastic is an even better way to find the focal point. Plus, by passing the laser beam through clear plastic, its approximate size and shape can be seen - whether it is round or flat or oval - and is a helpful way to visually teach laser principals. The plastic block used should be extremely clear (preferably acrylic) with flat, highly polished ends and sides, and at least several centimeters in length and thickness.

Another simple, and less expensive, way to find the focal point is to view the beam through a very thin sheet of translucent white plastic. The little plastic rulers given away at trade shows and other places are excellent for this purpose because such rulers are only about a millimeter in thickness and have a scale printed on one side. In order to use them, simply mount the laser in a stationary position, and place the ruler (with the scale facing away from the laser) into the laser beam, preferably near the end of the laser. As the beam passes through the translucent plastic, it will create a bright spot who’s diameter can be measured by using the scale printed on the ruler. As the ruler is moved away from the laser, the diameter of the beam will be seen to increase, decrease, or remain unchanged (in the case of a collimated beam). If the beam is found to be decreasing in diameter as the ruler is moved further from the laser, it will at some point decrease to its smallest diameter and then begin increasing in diameter again as the ruler is moved even further away. The point at which the beam is smallest in diameter is the laser’s focal point, and also the point of highest temperature anywhere along the length of the beam. It is at this point where lasers will be most able to pop balloons, light matches, etc.

It should be obvious to all that it is imperative that quality laser goggles be worn when doing such measurements because the only way to accurately read the scale is to have your eyes very near the beam itself. Remember the earlier warning that laser goggles are not designed to look directly into a laser beam, so do not risk your vision by doing so. Note also that what is read on the ruler’s scale is not the actual diameter of the laser beam. In reality the beam is much smaller, but because it becomes diffused as it passes through the plastic sheet, it appears quite large. Also note that because of diffusion, the thicker the plastic, the larger in diameter the beam will appear to be. If it becomes necessary to adjust the focal point of a laser module, remember that the further the lens is from the laser, the closer to the laser the beam’s focal point will be, and vise versa.

D -- Always describe as completely as possible the nature of the target used in the experiment or demonstration. When using things like balloons as targets, remember that the greatest heating effects occur in colors which are contrasting to the color of the laser. For instance, when demonstrating a red laser, a teacher might find it impossible to pop a red balloon, whereas a green balloon might be popped easily. This is because the red balloon transmits most of the red light, while the green balloon tends to absorb it, thus heating quickly and popping. The reverse is also true: A green laser will more readily pop red balloons than green ones. Both color lasers might be able to easily pop black balloons because the black color readily absorbs both frequencies of light. Balloons of any color can be made easier to pop by darkening a small portion of their surface with a black Sharpie marker, or something similar. It is also well to note that the areas near the ends of a balloon have somewhat thicker rubber than the sides. Although this thick area is darker and passes less light, its thickness also requires more heat to pop the balloon. Even though the sides of a balloon are thinner and more transparent than the ends, it is normally requires less energy to pop a balloon by firing at its side.

When describing the effects of balloon-popping demonstrations and experiments, it is very important to tell what size a balloon is, its color, where the laser struck its surface, and (when possible) what brand balloon is used. That way other people can more accurately replicate the experiment, and/or compare one laser to another. The same care in documenting holds true when doing demonstrations of lighting matches, burning paper, cutting electrical tape, etc. It’s a waste of time to say that a given laser will light a match, without first specifying the color and brand of the match, the color and power level of the laser, the distance of the focal point, etc. It is also important to specify how the laser or module is mounted during the experiment. Often a given demonstration of power cannot be accomplished unless the laser is held very still by being secured to a tripod or other stationary object.

Our Perception Of Light

God said, “Let there be light, and there was light” (Genesis 1:3); and then Maiman and others came along and made some of it coherent and created a whole new universe of uses for light. Maiman’s first laser emitted red light, but since that time lasers have been developed which emit a variety of colors. The average human eye is most sensitive to green wavelengths around 555 nm, and colors appear less bright as they move toward the infrared or ultraviolet wavelengths. Because of this spectral sensitivity, the beams emitted by green lasers normally appear more visible than those emitted by other lasers, and can usually be seen for long distances, even in a very clean and low humidity atmosphere. This can be a blessing or a curse. In many uses, such as some described later, the brilliance of a green beam can obscure the visibility of objects and lights in the vicinity. In situations where this is a problem, unless there is some overriding reason to use a green laser, it is better to use a laser of another, less visible, color. Here are some links to better understanding of the physiology of vision and the spectral sensitivity of the human eye:

http://photo.net/photo/edscott/vis00010.htm
http://www.glenbrook.k12.il.us/gbssci/Phys/Class/light/u12l2b.html
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html
http://www.rwc.uc.edu/koehler/biophys/6d.html

Lasers Overview

Everyone using lasers needs to understand that lasers are dangerous, irrespective of their power levels. In general, low power, Class I, II, and IIa lasers, with output power levels less than 1 mW (a milliwatt is a unit of power equal to 1/1000th of a watt), pose very little hazard, albeit there is a possibility of eye damage if the laser is shined into the eye too long. The millions of bar code scanners in use around the globe are proof, however, that low power lasers pose little hazard. Medium power, Class IIIa lasers, from 1 mW to 5 mW, can cause permanent eye damage from only seconds of direct beam exposure, but in general they too pose little danger, according to most ophthalmologists. But lasers always carry an element of danger: A scientist tells of a painful incident while checking for dust on the lens of a 4.5 mW laser. As he was looking down the barrel of the laser with a otoscope, he accidentally hit the laser’s power button. He recalls that it felt like someone put a fist in his eye and for the next twenty minutes or so all he could see (out of that eye) was red.

Sometime later, after an exhaustive eye exam, it was shown that he had no permanent damage, but this anecdote illustrates why it is so important never to shine any laser toward people’s faces, or toward surfaces which can reflect beams toward their faces. Dangerous or not, common courtesy and respect should always guide laser users to be mindful of the safety and feelings of others, or, paraphrasing an ancient Biblical admonition, “treat others in the same way you would like them to treat you.” For more on the debate of low-power laser dangers, here are some websites well worth visiting:

http://bjo.bmj.com/cgi/content/full/83/10/1164
http://vision.about.com/gi/dynamic/offsite.htm?zi=1/XJ&sdn=vision&cdn=health&tm=9&gps=184_1055_827_571&f=00&su=p284.21.140.ip_p284.2.420.ip_&tt=2&bt=0&bts=0&zu=http%3A//www.uni-duesseldorf.de/WWW/MedFak/LaserMedizin/hering/laserpointer/laserpointer_engl.html
http://www.mayoclinic.org/news2005-rst/2800.html
http://www.eschoolnews.com/news/showStory.cfm?ArticleID=929
http://laser.physics.sunysb.edu/~wise/wise187/2005/reports/deb/report.html

Medium power, Class IIIb lasers, which output from 5 mW to 500 mW, such as the OEM laser modules sold by Warn Laser, should be considered extremely dangerous and be given the same respect - and handled in the same manner - as a loaded firearm. They are designed to be the heart of laser systems used for research, education, rescue, and police and military purposes, and must never be aimed at people, animals, occupied buildings, cars, boats, or airplanes. Not only do they have the potential to do damage to unprotected skin and eyes, our more powerful modules have been known to accidentally ignite flammable objects. Even momentary specula or diffuse reflections from such powerful laser modules can do permanent retinal damage in some people, and prolonged exposure may cause cataracts and other eye disorders.

Because of this potential danger, we strongly encourage everyone working with lasers to protect themselves and their co-workers with proper laser eyewear. Eyesight is too precious to lose!!! We sell professional grade laser goggles and safety glasses, and to encourage use, we sell them at our cost. While this policy generally means that our goggles are the least expensive available, there are many sources for quality laser eye protection, including numerous internet sites, and even online auctions like eBay. Whatever brand eye protection you decide to use, make sure that it is a high quality product which meets appropriate military and industrial specs for the frequency laser you are using. It does little good to wear laser goggles or laser safety glasses which only attenuate green laser light if you are using a red or infrared laser!! And remember to use laser goggles only for their designed purpose. Using them as welding goggles, or for viewing solar eclipses and other intense light sources, may cost you your vision.

Before using any laser goggles, inspect them for scratches in the coating which could allow a harmful amount of light to enter your eyes; and when cleaning them, always follow the manufacturer’s cleaning instructions carefully. When using laser goggles, never look directly into a laser beam. Laser eyewear is not designed to totally block any given frequency of light, just reduce reflected light intensity to a relatively safe level. Also, never try substituting sunglasses or similar eyewear for real laser goggles. The attenuation provided, even by dark sunglasses, does little to reduce laser beam intensity. Even polarized sunglasses are not a safe substitute. Laser light is polarized, and thus can be greatly reduced in intensity with a polarizing filter. However, unless orientation of the light in the laser beam - direct or reflected - is exactly perpendicular to the polarization of the glasses, there won’t be enough attenuation to provide adequate protection. Trying to maintain the necessary orientation while moving and doing laser experiments is virtually impossible. Your eyes and the eyes of your friends and co-workers are worth far more than the cost of quality laser eyewear, so don’t be stingy or you might spend the rest of your life regretting it. In commenting on the importance of using quality safety equipment, the book “RAPPELLING,” by Tom Martin, perhaps says it best: “If you are too poor - or too cheap - to go first class, then don’t go at all.” If you are going to work with lasers, always wear quality laser eye protection - that’s the Warn Laser philosophy!

Warning: Powerful lasers must always be used and stored in the same manner as firearms. They must never be allowed into the hands of children or irresponsible or inebriated adults. When using any laser, always treat the people around you in the same way you would like to be treated.

Modifying Lasers

Modifying (or moding) lasers is a way to sometimes increase their output power - if this has not been optimized by the manufacturer. Generally, moding a laser module requires opening up its housing and messing with its guts. Sometimes a bit of power improvement can be had, but often in the process of making the laser modifications, something will go wrong and the diode will be damaged or destroyed. Laser diodes are one of the most sensitive and delicate of electronic components, and merely touching one improperly can cause it to burn out (thanks to static electricity on one’s hands). Normally, opening the housing of a laser module will void any warranty it might have, so it’s wise to consult the module’s manufacturer before doing so.

Before attempting modifications on any laser module, make sure the power supply is removed or disconnected, and that any safety interlocks are properly in place. Pocket lasers do not contain high voltage power supplies or capacitors, but many lasers do, so make sure all capacitors are fully discharged before doing any mods. Until all power is disconnected and all capacitors discharged, be sure and wear proper laser eyewear.
There are several things for improving power, such as lens cleaning, which can be safely done to any laser without voiding the warranty. One of the most important things is anointing all accessible electrical contacts with oxide inhibiting grease (De-Ox), like that used by electricians when installing aluminum wire. In a laser which is powered by batteries, smearing a tiny bit on the battery contacts, and on the ends of each battery, can go a long way toward coaxing more power out of the laser. Pocket lasers generally have some manner of screw-in cap to hold the batteries in place, so be sure and lightly grease the threads on this cap. Only a microscopically thin film of oxide inhibitor is needed, so don’t smear large wads of it around to foul up other internal components. The use of De-Ox is not just for aluminum wiring or pocket lasers. It’s a great way to improve reliability in flashlights and other battery-powered devices. The stuff is fairly expensive, 1 ounce usually costing $5 U.S. dollars, but 1 ounce should be enough to treat at least 10,000 lasers or flashlights.

Lasers In Medicine

The use of lasers in medicine is now widespread. They are primarily being used for surgical procedures on eyes, blood vessels, and other body parts. Less powerful lasers are being used for noninvasive therapeutic purposes, such as stimulating healing of muscles and reducing pain and swelling in joints. Medical lasers are expensive because they generally produce great amounts of power and they must meet rigid government specifications. There are, however, some medical uses for less powerful lasers. Reports from WarnLaser customers tell about using lasers to treat osteoarthritic joint pain, muscle soreness, and other conditions. A gentleman told of irradiating a sore arthritic finger joint for about one minute with a 150 mW Pulsar. Weeks later he still had no pain in that joint. A fellow reported using a Pulsar to irradiate the sore muscles in his foot. Although the pain still remained afterwards, he reported that it was dramatically lessened. At Warn Laser we are not doctors, and our laser modules are absolutely not being marketed as medical devices. Still, such reports from our customers are intriguing, and well worth publishing.

In general, the longer the wavelength of light, the deeper it will penetrate into living tissue. The red light of a Pulsar, being of fairly great wavelength, and of similar color to blood and tissue, can penetrate deeply and possibly stimulate certain useful chemical and electrical changes. There have been reports of using green lasers for therapeutic purposes, but because of the contrasting color of blood and tissue, there is no way that green light can penetrate as deeply as red light. It must be understood that anecdotal reports from our customers does not, in any way, mean that our lasers have medical value. The positive effects which have been observed could easily be explained by the soothing heat generated by the lasers. Also, the power of positive thinking - the placebo response - could explain every report that we have received. To really know the truth of the matter, well controlled, double-blind medical studies would have to be conducted. However, that being said, the possibility of such medical values should not be dismissed.

When using lasers for therapeutic purposes, remember that used improperly, they can do great harm. A laser beam hitting flesh for even a short period of time can cause severe burns, particularly in people with black or dark colored skin. Green lasers pose a greater danger than red lasers, in this respect. If it is deemed necessary to use a laser for therapeutic purposes, it is important to keep the laser moving so that excessive heat will not be built up in any localized area of flesh; the only exception being when a laser is used for germicidal purposes. Also, because of the unknown factors in prolonged laser exposure, the same body parts should not be irradiated frequently.

Another interesting medical use for pocket lasers (of substantial power level) is that of a “pocket fluoroscope.” In emergencies, a red laser may be able to be used to inspect bone damage or look for objects embedded in the hands and feet or other thin body parts. The way this is done is to go into a dark area and press the laser against the skin on the back side of the area to be examined, such as on the palm of the hand, or on the bottom of the foot, near the toes. Lasers of substantial power may be able to provide enough illumination to produce visible shadows of broken bones, shrapnel, splinters, etc., through a centimeter or more of tissue. Like real fluoroscopy, it takes a bit of experience to know what you’re seeing. Only red lasers will work for this purpose because the light from green or blue lasers will be almost totally absorbed within the flesh being examined. Very powerful flashlights could also be used for this purpose, but may not show as much detail because of the width of the flashlight’s beam. As in most medical uses, it is important to keep the laser moving, so as to not cause burns. This is one of the few situations when it is acceptable to operate a laser without wearing laser goggles - and must be done using extreme caution. One careless move and you might be looking down the barrel of an active laser - perhaps for the last time out of that particular eye!

Although relatively impractical, in field emergencies where antiseptics are not available, a pocket laser might be able to be used to sterilize small dressings, medical instruments, and even small areas of flesh, such as shallow puncture wounds from animal bites, nails, etc. Full destruction of bacteria would be a miracle, but a 40% kill rate might be expected after irradiating an area for one minute with a 100 mW red laser. In an emergency situation, any degree of sterilization might be better than nothing - so long as no harm is done in the process. In one experiment, bacteria were more effectively killed by a red laser than an infrared one, so most probably; at any given power level, green lasers would be more effective germicidal tools than red ones. For eye health, such procedures should never be undertaken without the benefit of proper laser eyewear. The following links may be of value to those researching the medical uses of lasers:

http://cooperativemedicine.com/laser_library/Arthritis%20-%20Osteoarthritis.pdf
http://www.cesil.com/0598/engiav05.htm
http://users.med.auth.gr/~karanik/english/vet/laser1.htm
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12627274&dopt=Abstract

Measurements With Lasers

Lasers can be of great value in night rescue or military operations, when fording of shallow streams and rivers becomes necessary. If the water is relatively clear, lasers enable a quick assessment of comparative depths at various places in the body of water. In nighttime operations, night vision equipment, even Generation 3 goggles, are of little help when there is a need to determine where to cross a creek or shallow river. This is because present night vision equipment can see only the surface of the water, and not what is beneath it.

The laser depth measurement method, although crude and inaccurate, can be helpful in determining where the shallowest water is and what underwater obstructions might be present.

The technique works best if the water is clear or only slightly murky, although it can work in very shallow muddy water. The beauty of the technique is that it can be used before reaching the stream or river. For instance, looking down from a ridge, it may be possible to quickly scan the waterway in the valley below and determine where would be the logical place to ford. It is important that the laser used for depth finding have a collimated beam, and it is preferable that it be a powerful red laser, such as the Pulsar or Red Spyder II. Green lasers can be used, but the brightness of the beam (before it hits the water) can make it difficult to see subtle changes in water depth. Often, it will be helpful to use binoculars or night vision goggles when depth finding, particularly if you are far from the body of water. In combination with night vision equipment, low powered laser pointers can also be used for depth finding, but they do not provide nearly as much useful information as the higher power lasers.

This depth measurement method works because as the laser beam travels down through the water, the beam is diffused by particulate matter in the water. Each microscopic particle reflects light back toward the surface and so a luminescent glow develops around the beam. In most situations, the further down into the water the beam travels, the greater in diameter this luminescent glow becomes. By moving the beam around, it is often possible to ascertain where the water is most shallow, or where holes and rocks are.. It takes much experience to be able to quickly and accurately determine depth using this technique because the size of the luminescent circle will be different from one body of water to another, primarily because of differences in water clarity. How well it works depends on how far the laser is from the water, the angle at which the beam enters the water, water clarity, and a number of other factors. It is certainly not a good way to determine where to ford, but it is sometimes the most practical way.

Fishermen and other outdoorsmen can use this technique to determine the best areas for night fishing, or to locate underwater obstructions such as logs, rocks, sunken boats, etc.

Because many aquatic species are attracted to bright light, a laser might be used to attract fish to a given area, or to determine what manner of life lives beneath the surface. It should be noted, however, that some species of fish are scared off by the bright beam of a laser, as are certain creature which live above the water.

If water is relatively clear, a laser can also be used as a tool to illuminate underwater terrain and make it visible to those looking into the water from above. This method is not as good as placing a powerful light under water, but it can be done from a distance, and without getting into the water. In some situations, particularly when using low powered lasers, night vision goggles will enable a better view of the underwater terrain.

In covert ops, if night vision equipment is available, an infrared pocket laser can be used for depth measurement. The laser is used as previously described, and the beam and resultant illumination viewed with night vision goggles. Should an infrared laser and night vision equipment not be available for the covert operation, use a red laser rather than a green one. The red beam will be far less visible than a green beam and the operation less likely to be detected by the enemy.

When using lasers for depth finding, laser goggles obviously can’t be used, so extreme caution must be taken not to direct the beam into anyone’s eyes.

Poor Man’s Radar

At night, if night vision isn’t available, one can often use a laser to get an idea of what the terrain far ahead looks like. By waving the laser back and forth, trees, vehicles, utility poles, buildings, small hills, and other objects are made visible in a crude but colorful way. This technique is no substitute for high-grade night vision, but it’s certainly better and safer than “being in the dark” about what lies ahead. This technique is best done with a low powered laser pointer, so that no danger will be posed to people, animals, or aircraft in the distance - or your own eyes. The reason to consider your own eyes is because when flashing a laser around in the dark, you will eventually hit a highly reflective object and have the beam reflected back at you. This is one those situations in which wearing laser goggles is not wise because moving around in the dark, with your vision impaired by light-limiting eyewear, is not a smart thing to do. When using high powered lasers, such as those sold by Warn Laser, the beam intensity should be attenuated down to a safe level, as previously described. Any color laser can be used for this crude “radar” technique, but red is probably best because the dot (where the beam impacts against an object) is less obscured by the brightness of the beam itself. Plus, in covert operations, a red beam is much less likely to be spotted by the enemy than a green beam - unless, of course, the enemy is equipped with night vision.

Laser History

To project a stream of powerful energy has long been a dream of man. In “The War of the Worlds,“ early science fiction writer, H.G. Wells, wrote of a laser-like weapon used by the Martians against humans. In newspaper reports as early as 1924, there were stories of electrical genius, Nikola Tesla, inventing a “death ray” which could destroy airplanes at distances of 250 miles. Although Tesla had immense intellectual capacity, and his research into alternating current is one of the pillars of modern technology, there appears to be no hard evidence that he created any kind of directed energy weapon (DEW). He certainly worked with light in some of his research, but he was not the inventor of what we call the laser.

That honor most likely goes to Dr. T.H. Maiman at the Hughes Aircraft Company who, in 1960, placed a ruby rod inside of a coiled flashtube and produced a red burst of coherent light, at a wavelength of 694 nm (nanometers), which was powerful enough to burn a hole through a Gillette razor blade. Sir Isaac Newton once said: “If I have seen further than [others] it is by standing upon the shoulders of Giants.“ Preceding Maiman’s monumental achievement was centuries of research and thinking by many great minds, not the least of which was Albert Einstein. The name “LASER” can be attributed to Gordon Gould while he was working on his doctorate at Columbia University. It is an acronym for “Light Amplification by Stimulated Emission of Radiation” and refers to an optical source that emits photons in a coherent beam. Here are some links to excellent resources on the history and technology of lasers:

http://en.wikipedia.org/wiki/Directed-energy_weapon#The_beam_being_absorbed_by_obscuration_in_the_air
http://en.wikipedia.org/wiki/Laser
http://ksks.essortment.com/historyoflaser_rsny.htm
http://inventors.about.com/od/lstartinventions/a/laser.htm

Maiman’s laser used a ruby rod which was ground to the appropriate length and had one end fully silvered and the other end 99% silvered, thereby creating a resonant optical cavity. It

was considered a solid state laser. Later, other scientists found way to stimulate the emission of coherent photons from gas, and a whole new breed of lasers emerged. The most widely used gas lasers are those containing a mixture of helium and neon (HeNe lasers). As even more research into lasers was done, scientists discovered how to stimulate coherent photon emission by a mixture of chemicals, and the chemical laser was born. As semiconductor technology evolved, discoveries were made which led to the most widely used type of laser - the diode laser - which is so prevalent today in many types of electronic devices, including DVD burners, which contain diodes with outputs of several hundred milliwatts. The laser modules manufactured by WarnLaser use the diode type of laser.