DEFINITION OF LASER TERMS

           For the benefit of those who are new LASER Enthusiasts or hobbyists, I believe it will be helpful to have a guide to some of the more common terminology used in this "hobby". Well, here it is for all it's worth.

Accumulation of Tolerances: This is an engineering term that describes how manufacturing tolerances; i.e.: how much one manufactured part differs from other, identical parts, can add or subtract to how well parts fit together or perform as an assembled unit. It is best to illustrate this with a simple example: Suppose you were manufacturing a simple plane bearing; i.e.: one that does not use ball bearings. In order to have a precision bearing that will not wear prematurely, or rattle as a shaft spins inside it, the shaft must fit precisely into the bearing, while still allowing a thin film of lubricant to leech into and remain between the surfaces. A few thousandths of an inch here, means that the bearing will fail. Suppose for the sake of argument that the tolerance for the shaft diameter are ±0.001", and the tolerance for the bearing inside diameter is also ±0.001". In such a case, the two extremes based on the "perfect" fit would be ±0.002". If you try to put together the two parts and the shaft diameter is +0.001" larger than the "ideal", and the bearing diameter is  –0.001" less than the "ideal", the shaft will not fit inside the bearing. If, on the other hand, the shaft diameter is –0.001" smaller than the "ideal", and the bearing diameter is  +0.001" larger than the "ideal", the shaft will be too loose in the bearing, and it will oscillate and eventually fail.

Everything that is made by Man has such tolerances - LASERS included. If you have a diode that puts out 800mw at 1,000mA, the next one you measure might give you 780mw for the same amount of current. The next diode you measure might give you 810mw for the same amount of current. And so it goes for the driver boards as well. So there is an unavoidable variance in manufactured components, and the engineer's job is to minimize those variances as much as possible.

Active LASER Medium: (aka: gain medium, lasing medium) - simply defined, this is the crystals, glass, gas, or semiconductor medium that is "pumped" or "excited" by external stimuli such as a flash tube in a Helium-Neon (HeNe) gas LASER. (see: article on Wikipedia)

AIO: Acronym for "All In One". This term usually refers to a scanner / printer / fax / phone / copier that is built into the same unit. One or more of the functions can be missing from the list. Usually, 3 of the 5 qualifies a unit as an "AIO".

Apparent Power/Brightness: The intensity of light as it appears to the human eye. The eye is most sensitive to wavelengths (colors) in the center of the visible spectrum. Hence, green light will appear brighter than any other color of light of the same power or magnitude.

Beam Diameter: (also see: FAQs and Divergence) The distance between diametrically opposed points in the cross section of a circular beam where the intensity is reduced by a factor of 1/e (0.368) of the peak level (for safety standards). The value is normally chosen at 1/e2 (0.135) of the peak level for manufacturing specifications.

Beam Divergence: (also see: FAQs and Divergence) Angle of beam spread measured in radians or meliorations. For small angles where the cord is approximately equal to the arc, the beam divergence can be closely approximated by the ratio of the cord length (beam diameter) divided by the distance (range) from the LASER aperture. The longer the distance a LASER beam travels, the more it spreads, or diverges.

Buck / Boost: Constant Current Drivers work by varying the output voltage into a load (diode in this case) so that the current flow at the diode remains at a fixed value. This is a simple explanation of what the circuit does:

     If the supplied input (battery) voltage is BELOW the voltage required to achieve the desired current flow at the load (diode), the circuit BOOSTS the output voltage (typically with the use of an inductor / transformer circuit) so that the voltage output is greater than the input voltage – it does this by drawing MORE current from the battery than it supplies to the load; effectively trading increased current draw from the battery to gain the voltage required to maintain a fixed current flow to the diode.

     If the supplied input  (battery) voltage is ABOVE the voltage required to achieve the desired current flow at the load (diode), the circuit BUCKS the output voltage (typically with the use of an inductor / transformer circuit) – it does this by drawing LESS current from the battery than it supplies to the load; effectively trading decreased current draw from the battery to reduce the voltage required to maintain a fixed current flow to the diode.

      Since our proprietary driver incorporates such a circuit, battery configurations are more flexible than with other drivers. For example, the Cobalt 2000 / SF requires a minimum of two # 18650 batteries, but can handle up to 6 (six) of these batteries in series (using extension tubes). Using more batteries does NOT increase the output power, but dramatically increases the life of the batteries before they have to be recharged.

Boost Driver: A boost driver maintains constant current to the LASER diode by drawing more current from the battery when the battery voltage decreases (battery becoming discharged). The circuitry uses a micro-inductor coil as a transformer of sorts; not unlike the spark plug coil in your car. The driver continues to increase the current draw on the battery as the input (battery) voltage decreases, in order to keep the drive current to the diode constant. The driver continues to do this until the input voltage drops below the minimum input voltage of the driver, at which point the driver shuts off. When the battery recovers a bit of charge, the driver may start operating again. With Li-ion batteries, the recovery time is very fast, so the LASER may start blinking very fast when the batteries are approaching end of charge. The rate of "blinking" slows as the battery is discharged to a level where it can no longer "recover" to the point of satisfying the minimum voltage requirement of the driver, at which point the LASER will no longer operate.

Capacitor: A capacitor (formerly known as condenser) is a passive electronic component consisting of a pair of conductors separated by a dielectric (insulator). When there is a potential difference (voltage) across the conductors, a static electric field develops in the dielectric that stores energy and produces a mechanical force between the conductors. (see article on Wikipedia).

Center-Mass Hold: A military / police term that describes the aiming of a pistol or rifle to the "center mass" of the target. In the military, CMH is the standard practice. Although "head shots" are almost always effective, they are harder to achieve because a head presents 1/3 the of the target area than the upper torso. CMH shots are just as effective with the new weapons, and easier to achieve at any appreciable distance. However, CMH shots are less effective if the target is wearing a "bullet-proof" vest, or the weapon being used is not capable of penetrating personal armor at the distance.

Chinklish: A word I coined to describe this: Not to hold dyode by han with the wyer, danger have stactic run into device make laser work no, and if luck have no destroy, but no so goo working after. Connect pos (+) lead to pad left side under front in small hole under resister. Have (-) lead an neut wire to rite pad side down. Hold swich moment for tes. Careful be not  see red light more than 3s it is eye harmfull too.

That is Chinklish from an actual instruction sheet. Your guess is as good as mine.

Coherence: A term describing light as waves which are in phase in both time and space. Monochrome (single color frequency) and low divergence (beam spread angle is very narrow) are two properties of coherent light.

Collet: A chuck or holding device. In this context, a "collet" works differently than collets used in power tools as defined by Wikipedia. In the case of flashlight to LASER conversions, a typical "collet" is two pieces designed to hold a part (such as an LED module or circuit board0 in place.

Collimated: Collimated light is light whose rays are nearly parallel, and therefore will spread slowly as it propagates. The word is related to "colinear" and implies light that does not disperse with distance (ideally), or that will disperse minimally (in reality).

Constant Wave (CW): The output of a LASER that is operated in a continuous (pulse duration >0.25s) rather than a pulsed mode.

Crenellated: Something with battlements or crenels, or with squared notches (Yourdictionary); a parapet (i.e. a short wall), in which portions have been cut out at intervals to allow the discharge of arrows or other missiles (Wikipedia). In the sense used on this Web site, it means a bezel or ring with cutouts mounted on a flashlight for use as a defensive weapon.

CRITSTEP™: An abbreviation or acronym for "CRITical STEP". This was an option for our former LASER Kits. Adding this option to a kit purchase saved the kit builder from performing critical or delicate tasks such as micro-soldering of SMT components, or making adjustments where special equipment (such as Digital Multimeters) that the kit builder might not own is required. We have eliminated the need to select CRITSTEP™ options in all our new kits.

Dielectric: is an electrical insulator that may be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric polarization. Because of dielectric polarization, positive charges are displaced toward the field and negative charges shift in the opposite direction. (see article on Wikipedia)

DAA: Dead After Assembly. (also see: DOA)

Diode: A device through which current can pass freely only in one direction. The diode is arguably one of the most important components in a LASER. Oftentimes the lifetime of a LASER is based on the quality of the diode.

DirectBlue – A new (early 2010) LASER technology that permits direct generation and emission of 445 nm (true blue0 LASER radiation without the use of complex optics required by DPSS LASERS (see below). This technology permits the cost-effective manufacture of extremely efficient, high-power LASER diodes. These diodes also make possible the manufacture of insanely powerful portable (hand held) LASERS with outputs of 1,500 mw.

Divergence: (also see: Beam Diameter and  FAQs) Like all electromagnetic beams, LASERS are subject to divergence, which is measured in milliradians (mrad) or degrees. The divergence number is a measure of the spreading of the beam with distance from the aperture. For many applications, a lower-divergence beam is preferable. Poor beam quality notwithstanding, the divergence of a LASER beam is proportional to its wavelength and inversely proportional to the diameter of the beam at its narrowest point. For example, an ultraviolet LASER that emits at a wavelength of 308 nm will have a lower divergence than an infrared LASER at 808 nm, if both have the same minimum beam diameter. The divergence of good-quality LASER beams is modeled using the mathematics of Gaussian beams.

DIY: Abbreviation for "Do It Yourself".

DMM or VOM: – Digital Multimeter – also known as a volt/ohm meter or VOM, is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current, capacitance and resistance. (See article on Wikipedia).

Almost any serious electronic hobbyist owns a DMM of one sort or another. Our requires the use of a DMM to complete critical steps in the assembly process. Since many LASER Enthusiasts aren't necessarily Electronic hobbyists, we added the CRITSTEP™ option to our Kit LASERS, so that steps requiring the use of such equipment is already done.

DOA: Dead On Arrival (also see: DAA)

DPSS: Acronym for Diode-Pumped Solid-State – (see DPSS LASER in FAQs)

Dummy Load: Ais a device used in place of a LASER diode to aid in adjusting the diode driver. It is substituted for the diode while adjusting the driver, so that the output current can be adjusted before the diode is connected. This ensures that the diode is not inadvertently harmed by too much current being supplied by a mis-adjusted driver.

Duty Cycle:  the duty cycle is the fraction of time that a system (or device) is in an "active" (or "on / energized) state. Duty cycle is the proportion of time during which a component, device, or system is operated. Expressed mathematically, the Duty Cycle of a system or system component is expressed as D = τ / T  where τ is the duration that the function is active high (normally when the signal is greater than zero); and T is the period of the function. (see: article on Wikipedia)

Emery Board: (a type of disposable nail file) is a piece of cardboard that has a type of fine sandpaper glued to it, making them it abrasive and flexible. Emery boards are primarily used for fingernail and toenail care. They are used by manicurists to shape and smooth the nail during manicure and pedicure sessions. Emery boards are inexpensive and disposable, making them a sanitary alternative to metal nail files.

ESD (Electro-Static Discharge): ESD is the sudden and momentary electric current that flows between two objects at different electrical potentials caused by direct contact or induced by an electrostatic field. The term is usually used in the electronics and other industries to describe momentary unwanted currents that may cause damage to electronic equipment. ESD is a serious issue in solid state electronics, such as integrated circuits. Integrated circuits are made from semiconductor materials such as silicon and insulating materials such as silicon dioxide. Either of these materials can suffer permanent damage when subjected to high voltages; as a result there are now a number of antistatic devices that help prevent static build up. (see article on Wikipedia)

Failsafe Interlock: An interlock where the failure of a single mechanical or electrical component of the interlock will cause the system to go into, or remain in a safe mode.

Frequency: The number of light waves passing a fixed point in a given unit of time, or the number of complete vibrations in that period of time. The higher the number of waves passing a fixed point, the higher the frequency.

FRU: Military Acronym for "Field Replaceable Unit" - This term usually refers to a piece of equipment which is self-contained and / or cannot be easily broken down into component parts or easily repaired in the field. FRUs make it simple for a minimally-trained or even untrained operator to repair a piece of complex equipment in minimal time.

Gain Medium: (see: Active LASER Medium)

Handy-Andy™: A brand of toy tools (ages 2-3) that used to be popular – most probably before you were born. Santa Claus brought me a complete set for Christmas when I was about 3 (yes, I still remember), and even as TOYS, they sucked. Radio Shack tools – especially their "soldering irons" – max-out the Handy-Andy Suck-o-Meter.

Heat Sink: A substance or device used to dissipate or absorb unwanted heat energy. Hand-held LASERS of appreciable power use brass or aluminum housings – usually ferruled to increase surface area – as heat sinks.

H_eN_e: Chemical abbreviation for Helium / Neon. This combination of gases is used to produce Red LASERS.

Hilt: The handle of a sword or saber. Common synonym in the LASER Community for "Host" (see below. Also see: Pill).

Host: The enclosure, chassis, modified flashlight or custom "hilt" that houses the LASER components and power source (see above. Also see: Pill).

Infrared (IR): Infrared radiation (IR radiation) is electromagnetic radiation with a wavelength between 0.7 and 300 micrometres, which equates to a frequency range between approximately 1 and 430 THz. Its wavelength is longer (and the frequency lower) than that of visible light, but the wavelength is shorter (and the frequency higher) than that of TeraHertz radiation microwaves. Bright sunlight provides an irradiance of just over 1 kilowatt (1,000 Watts) per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet (UV) radiation.

KIA: Acronym for "Killed In Action"

KIT: {Definition of the word "kit"}

Wikipedia defines it best: "An electronic kit is a package of electrical components used to build an electronic device. Generally, kits are composed of electronic components, a circuit diagram (schematic), assembly instructions and often a printed circuit board (PCB). People primarily purchase electronic kits to have fun and learn how things work."

Free Dictionary: "A set of parts or materials to be assembled: a model airplane kit."
Merriam Webster Dictionary: "a set of parts to be assembled or worked up <a model-airplane kit> "
YourDictionary.com:  "a set containing a number of parts to be assembled: a model airplane kit".
Answers.com: "A set of parts or materials to be assembled: a model airplane kit".

KTP: Potassium Titanyl Phosphate. A crystal used to change the wavelength of a ND:YVO4 LASER from 1064nm (infrared) to 532nm (green)

LASER: An acronym for Light Amplification by Stimulated Emission of Radiation. A LASER is a cavity, with mirrors at the ends, filled with material such as crystal, glass, liquid, gas, or dye. A device which produces an intense beam of light with the unique properties of coherence, collimator, and monochrome.

LASER Class: The Food & Drug Administration (FDA) regulates, as the name implies, foods and drugs. However, they also regulate all radiation emitting products, which include LASERS. The subgroup of the FDA in charge of regulating radiation emitting products is the Center for Devices of Radiological Health (CDRH). They have divided LASERS into several classes based on output power. See: LASER Class Chart.

LASER Diode: A laser diode is a LASER where the active medium is a semiconductor similar to that found in a light-emitting diodes (LEDs). The most common and practical type of laser diode is formed from a p-n junction and powered by a DC electric current such as a battery.

LASER Diode Module: A complete LASER package including the circuitry, a LASER diode, and all optical components assembled into a protective housing usually called a "Pill". The only additional requirement to power the LASER diode module is an appropriately matched power supply or battery.

Awesome LASERS Pills use our Proprietary LASER Diode and Patent Pending Driver boards in a ceramic-epoxy encapsulated Pill. This makes the LASER waterproof and shockproof – practically indestructible.

Lasing Medium: (see: Active LASER Medium).

LASER Power Meter (LPM): A meter employing a sensor "head" or thermocouple used to measure the actual output power of a LASER.

Longitudinal or Axial Mode: Determines the wavelength bandwidth produced by a given LASER system controlled by the distance between the two mirrors of the LASER cavity. Individual longitudinal modes are produced by standing waves within a LASER cavity.

M2: A measurement of LASER quality. M2 is a single number that describes the beam's quality in comparison to a theoretically perfect Gaussian beam, and that can be used to predict a real, non-Gaussian beam's behavior in an optics system.


Milliampere (mA): A unit of current equal to one thousandth (10^-3) of an ampere. The current draw of a LASER is often measured in milliamperes (mA) or amps (A). (also see: MilliWatt or mw)

Milliradian (mrad): A unit of angular distance equal to one thousandth (10^-3) of a radian. It is used to measure LASER beam divergence.

Milliwatt (mw): A unit of power equal to one thousandth (10^-3) of a watt. It is used to measure the output power of most low to mid-power LASERS. Generally LASERS that exceed 999mw are measured in watts. For example, a 1,000mw LASER would have a power output specification of 1Watt. (also see Milliampere or mA)

Mode: A term used to describe how the power of a LASER beam is geometrically distributed across the cross section of the beam. Also used to describe the operating mode of a LASER, such as continuous or pulsed.

Modulation: The ability to superimpose an external signal on the output beam of the LASER as a control.

Monochrome: Light consisting of a single color frequency. In physics, monochromatic refers to electromagnetic radiation of a single frequency. In the physical sense, no source of electromagnetic radiation is purely monochromatic, since that would require a wave of infinite duration as a consequence of the Fourier transform's localization property (cf. spectral coherence).

MPE: Acronym for Maximum Permissible Exposure. This is expressed as a formula: i.e. 200mw/CM² Note that for LASERS of any type – but particularly the high-power blue LASERS – the MPE is very low, and the MSD (see below) can be hundreds of meters.

MSD: Acronym for Minimum Safe Distance. This is expressed simply as a unit of distance; miles,. kilometers, yards, meters, feet, etc. It is a statement that exposure to a radiation source (or light source) is safe at the stated distance or greater. With very low divergence angles, LASERS can cause eye damage at very long distances. Also see NOHD

MTTF or MTBF: Mean Time To / Between Failure. This is an approximation of the average lifetime expected out of a LASER diode.

Nanometer: A metric unit a length equal to one billionth of a meter. It is used to measure the wavelength of most LASERS. For example, some common red LASERS include 635nm, 650nm, and 660nm. Common green LASERS are 532nm and 557nm. Common blue LASERS are 405nm, 408nm, 445nm, 457nm and 473nm. A much larger wavelength, such as 1064nm, would be an infrared LASER.

ND:YVO4 LASER: Acronym for Neodymium: Yttrium Vanadium Quadroxide (O4). A synthetic crystal used as a LASER medium to produce 1064nm light.

Necrotizing / Necrosis: To cause death of living tissue / tissue death.  Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma (see article on Wikipedia). The photo shown here is the result of a Brown Recluse Spider bite. However, burns from a 445nm high-power LASER are indistinguishable; the results are identical. The tissue simply dies because the cellular structure has been disrupted by both the instantaneous heat from the LASER, and the near-ultraviolet radiation which causes cell (DNA) mutation (if not cellular death).

Ultraviolet radiation (such as from the sun) has been linked to many forms of skin cancer. The light frequency at 445nm is very close to the UV wavelength, and a burn from a LASER means that the skin was exposed to many thousands of times the UV radiation levels required for a very serious "sunburn".

NOHD: Acronym for NO Hazard Distance – The distance at which a particular LASER poses no hazard of injury to an observer directly viewing the beam. Also see MSD.

Operating Current: The range of specified current required to operate a LASER. LASER operating current is measured in Amps (A) or milliamperes (mA). A milliampere is 1/1,000^th of 1 Ampere.

Operating Voltage: The range of specified input voltage required to operate a LASER. LASER operating voltage is measured in volts (V).

Output Power: The energy per second measured in watts emitted from the LASER in the form of coherent light. LASER output power is measured in watts (W) or milliwatts (mw). A milliwatt is 1/1,000^th of 1 Watt.
 

Photonic:  Having to do with photons (light).

Picatinny Rail:    The Picatinny rail - MIL-STD-1913 rail or STANAG 2324 rail or a "Tactical Rail" is a bracket used on some firearms in order to provide a standardized mounting platform. A similar system is the Weaver rail mount. The name comes from the Picatinny Arsenal in New Jersey, USA where it was developed. The rail comprises a series of ridges with a T-shaped cross-section interspersed with flat "spacing slots". Scopes are mounted either by sliding them on from one end or the other; by means of a "rail-grabber" which is clamped to the rail with bolts, thumbscrews or levers; or onto the slots between the raised sections. (see article on Wikipedia).

Pill: This is a slang term used to describe the LASER diode heat-sink and driver board enclosure which is usually one or two pieces. The "pill" usually contains all the operating (or at least all the electronic) components of the LASER. The "pill" is mounted in a "hilt" or "host", which is the body of the LASER (usually a pen or flashlight style).

This photo shows a Pill from the Cobalt Series 2000 / UF and SF Model LASER Kits (tensioning spring is removed). The arrow points to a unique, hand engraved Pill serial number registered to the owner.

Polarization: Restriction of the vibrations of the electromagnetic field to a single plane, rather than the innumerable planes rotating about the vector axis. Various forms of polarization include, random, linear, vertical, horizontal, elliptical, and circular.

Pot: Abbreviation for "Potentiometer" – (colloquially known as a "pot") is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used (one side and the wiper), it acts as a variable resistor or rheostat. Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. The 'pot' on a typical LASER driver circuit board – which is usually SMT-Technology, is quite small; tiny, in fact.

Protective Housing: A protective housing is a device designed to prevent access to radiant power or energy.

Pumping: Addition of energy (thermal, electrical, or optical) into the atomic population of the LASER medium, necessary to produce a state of population inversion.

Shunt: A mechanical, electrically conductive connection across contacts. To see an example, read my article (see photos) on modification of a Spyder III G1 LASER to enable remote on / off control. In the case of LASER Diodes, what is referred to s a "shunt" is a small length of copper with two holes in it, soldered to the pins of the Diode to equalize static charges and prevent damage to the Diode from ESD.

SmartSwitch™: SmartSwitch™ is a trademark of Wicked LASERS that describes a safety feature incorporated into their most powerful Blue LASER, the Spyder III Arctic. As a safety feature, the LASER must be "unlocked" after turning the power on with the Tail Cap button. The user must "tap" the button 3 times quickly, then immediately "tap" the button again twice, this time holding it for 1/2 second. This "unlocks" the LASER, and puts it into low power "pulse" (50% duty cycle) mode. Subsequent long or short "taps" of the SmartSwitch™ cycle the operating mode to low power continuous, high power pulse, and high power continuous. Holding the SmartSwitch™ depressed for 3 seconds "locks" the LASER, and the "tap code" must be repeated to again operate the LASER. Turning the LASER off with the Tail Cap switch will also reset the LASER to "locked' mode the next time the Tail Cap power switch is pressed to turn the LASER "on".

SMT: Surface Mount Technology  is a method for constructing electronic circuits in which the components (SMC, or Surface Mounted Components) are mounted directly onto the surface of printed circuit boards. (see: excellent article on Wikipedia).

Stability: The ability of a LASER system to resist changes in its operating characteristics. Temperature, electrical, dimensional, and power stability are included.

TALI: Threat Assessment Laser Illuminator. A LASER that is used for long-range illumination of a target, typically at ranges where flashlights, floodlights, or flares would be useless or impractical. A LASER Illuminator can be useful to illuminate the inside of a car, or a room through a window. A flashlight or floodlight would cause so much glare from the surrounding environment that it would be difficult to see inside the car or room. A LASER shone into the closed space, will diffuse against the surroundings and allow you to see inside, without illuminating the outside of the vehicle or premises.   

TALW:  Tactical Assault Laser Weapon. A LASER that is so powerful, that when skillfully used, becomes a weapon in its own right. A 2,000mw LASER will cause instant and permanent blindness at close range, and serious and debilitating eye injury at longer distances. High-power LASERS can also permanently damage Infrared Surveillance equipment such as I-R scopes and Starlight scopes. Shone directly into a sniper's rifle scope or a spotter's binoculars, these LASERS can disable the shooter / spotter, and under the right conditions can cause debilitating eye injuries that would prevent them from sniping / shooting ever again. The military uses for these LASERS have the potential to save many American lives when used on the battlefield in Iraq and Afghanistan.

TEMoo: The lowest order mode possible with a bell-shaped (Gaussian) distribution of light across the LASER beam. See FAQs or complete article on Wikipedia.

Thermocouple: a junction between two dissimilar metals that produces a voltage related to a temperature difference (see Wikipedia).

Tin / Tinning: To use a soldering iron or soldering pencil to coat the surface of a printed circuit board or the strands of a wire with solder. For electronics projects, use ONLY "60/40" Rosin Core solder. Use of Acid Flux or "plumbing" solder for electronics projects will dissolve the connections in a matter of weeks. When used in reference to soldering guns or pencils, 'tinning' means to coat the surface of the soldering tip with a layer of solder in order to facilitate quick heat transfer from the iron / pencil to the pieces being soldered. If a soldering tip cannot be so coated, it is worse than useless for soldering.

Visible Radiation (light): Electromagnetic radiation which can be detected by the human eye. It is commonly used to describe wavelengths which lie in the range between 400nm and 750nm. The peak of the human spectral response is about 555nm.

Volt (V): The unit of potential difference and electromotive force. Generally used to measure the input voltage of a LASER power supply.

VOM: Volt / Ohm Meter (see DMM)

Wavelength: The length of the light wave, usually measured from crest to crest, which determines its color. Common units of measurement are the micrometer (micron), the nanometer, and (earlier) the Angstrom unit.

ZBLAN: ZBLAN glass is the most stable fluoride glass known and is most commonly used to make into optical fiber. Recent advances by ZBLAN fiber manufacturers have demonstrated significant increases in mechanical properties (>100 kpsi or 700 MPa for 125 µm fiber) and attenuation as low as 3 dB/km at 2.6 µm. ZBLAN optical fibers are used in different applications such as spectroscopy and sensing, laser power delivery and fiber LASERS and amplifiers.