This page provides easy-to-understand explanations of common laser marking terms.
A to C
|A/O Q switch||An acousto-optic method Q-switch that changes the refractive index of light by introducing ultrasonic waves.|
|Alignment beam||Alignment beams are auxiliary laser beams used to display the position of the primary marking beam and perform position adjustments. Since the primary marking beam is invisible, alignment beams are useful for visually confirming alignment.|
|Aperture||A device that refines the center of a laser beam by only allowing a specific diameter of laser light to pass through.|
AR is an abbreviation for Anti Reflection.
An AR coating is applied to the laser lens to prevent reflections from occurring on the lens' surface, thus improving the transmittance of the laser beam.
|Attenuator||An optical component or shutter that is used to adjust the intensity or power of the laser.|
|Beam diameter||Generally speaking, this refers to the diameter of a laser beam. Normally, this is used to specify the value of a beam center at half its peak value.|
|Beam divergence||An angular measurement of a beam diameter's growth as it leaves the oscillator.|
|Beam profile||A cross-sectional graph of a laser beam's power distribution.|
|Beam profiler||Instrument to measure the distribution of intensity for laser beam.|
|Chiller||A device that chills water and keeps it at a fixed temperature.
This is used as a secondary cooling device for water-cooled YAG lasers.
|CO2 laser||A laser that uses carbon dioxide as a medium and oscillates at a typical wavelength of 10.6 microns.|
|Complete air cooling||
An air-cooling method that uses radiator fins, fans, and Peltier elements to cool down laser equipment.
A system that uses a Peltier element to conduct heat away from and cool the laser oscillator. Uses air and does not require cooling water.
|Continuous wave||Oscillating a seamless, continuous laser beam (CW).|
D to F
Light with a wavelength shorter than 200 nm. Difficult to propagate outside of a vacuum.
ArF (193 nm) and F2 (157 nm) excimer lasers fall under the category of vacuum ultra-violet light.
|DPSS||An abbreviation for Diode Pumping Solid State. Synonymous with LD pumped solid state laser.|
|E/O Q switch||An electro-optic method Q-switch that changes the refractive index by introducing voltage.|
|End pumping||A method where excitation light is irradiated and energized from the rear of the laser medium. Because the center of the crystal is excited, the excitation efficiency is good, and a high quality laser beam is created.|
|Energy output||The amount energy over time (generally measured in Watts).|
|Feedback light||Laser light that bounces off a target surface and returns to the laser oscillator.|
|Fiber laser||A system that uses fiber for the resonator and creates an overlapping structure with fiber cladding that has been doped with Yb ions or other elements, after which it pumps laser diode excitation light inside.|
|First pulse suppression||Suppresses the initial giant pulse that is emitted with a Q-SW laser.|
|Flash lamp pumping||A system that uses a lamp as the excitation source of a solid-state laser.|
|Focusing lens||A lens (or combination of lenses) that collects and focuses light onto a target surface.|
A correcting lens that condenses a laser beam onto a planar surface to ensure a constant scanning speed anywhere in the marking field.
|Fundamental wave||The wavelength of a laser beam when oscillated from the laser medium. For example, YAG lasers have a fundamental wavelength of 1064 nm.|
|Galvanometer mirror||The mirror attached to the Galvonometer scanner.|
|Galvanometer scanner||A stepping motor used to control the mirrors that scan the laser beam across the marking field. Its can accurately control the angle of stop rotation.|
Laser systems that arc and discharge high voltage through a gas mixture sealed inside of a tube, changing the gas to plasma.
CO2 (carbon dioxide) and He-Ne (helium-neon) are commonly used. CO2 lasers are used for marking and processing, while helium-neon lasers are used as light sources in opto-electronics.
The optimal laser will differ depending on the desired processing application.
A pulse that possesses high-energy amplified via Q-switch.
A phenomenon where excess energy accumulation in the laser medium is released all at once, resulting in deep carved sections.
|Green laser||A laser that oscillates green light with a wavelength in the vicinity of 532 nm.|
H to I
As a laser's wavelength becomes shorter, its energy and absorption rate generally get higher. For example, a copper plate (Cu) only absorbs 10% of fundamental (1064 nm) laser light. However, the absorption rate of UV light is 50-60%.
|High reflective mirror||A mirror that reflects all light within the resonator.|
|Infrared light||Non-visible light that has a wavelength longer than 780 nm.|
|Inner marking||Transmitting a laser beam through a transparent object such as glass to perform marking or processing on the inside of the transparent object.|
|Ion exchange||The removal of ions and impurities generated from the water used to cool certain laser markers. This process maintains system cleanliness.|
Abbreviated form of Light Amplification by Stimulated Emission of Radiation. Lasers have the following qualities:
|Laser diode||Lasers created using semiconductor materials.|
The source material that produces a laser. Laser mediums include solids, liquids and gases because different sources will produce different beam characteristics.
|Laser oscillator||Equipment that amplifies and oscillates a laser beam through stimulated emission from an excited state.|
Processing performed using a laser.
|Laser trimming||A working process where resistor materials are trimmed to regulated resistance values.|
|LD||An excitation method that uses a Laser Diode for the light source that excites the laser medium.|
|LD pumping||Using a Laser Diode excitation light source to pump light into a laser producing medium.|
|Longitudinal mode||A state where laser beams of many frequencies are oscillated depending on the distance between resonator mirrors.|
M to O
|M2 (M square)||Specifies the quality, specifically the intensity distribution of the laser beam in the horizontal direction.
M2=1 is said to be the ideal single mode.
|Multi mode||A mode where the cross-section of light rays emitted from a laser oscillator appears as multiple peak points.|
|Optical isolator||A device that possesses the ability to pass light in a single direction only. Used to block return light from a laser.|
The mirror that passes an emitted laser beam that has been amplified within the resonator.
|Peak power||The divided value of pulse energy and pulse width. W (watts).|
|Polarization plate||An optical element that produces fixed-direction polarized light.|
|Power||Amount of energy over time, in W (watts) units.|
|Power meter||A device that measures the output of laser light.
Used to manage laser power attenuation conditions.
|Protective goggles||Safety goggles that are used to protect your eyes from laser beams.
Appropriate goggles are selected according to wavelength.
|Pulse energy||The amount of energy allotted to a single pulse from a pulse laser oscillator.
In J (joules) units
Oscillation involving a laser light that is produced in flashes. Pulse oscillation controls laser output by changing the oscillation frequency, making it possible to increase the amount of energy per single pulse. The values that express laser output are average output, peak output, and pulse energy. Their units are W (watts) and J (joules). Compared to the output value of a continuously oscillating laser, the peak output value for a pulse laser is high. However, average output is a number value that has added the oscillation frequency to the product of pulse width and peak output, making the average output power low. Even when the average output is a few W (watts), the peak energy of a pulse laser is +10 kW (kilowatts). This gives pulse lasers energy to mark and process metals.
|Pulse Stretcher||The structure or member that stretches the pulse width of a laser beam.|
|Pulse width||The irradiation time allotted to a single pulse from a pulse laser oscillator.|
|Pulsed wave||Oscillation of laser light at a fixed frequency. Opposite of Continuous Wave.|
|Pumping||Adding external energy to the atoms within the laser medium and changing from a low and stable state of energy to a high state of energy.
This high state of energy is called an excited state.
|Purified water||Water that has been chemically and physically treated to remove dissolved substances. Purified water is used for water-cooled laser markers because it is used as an insulator.|
Q to S
|Q switch||An optical component that places an absorber between the laser medium and output coupler and controls laser oscillation, creating high energy.|
|Resonator||The area between the high reflective mirror and output coupler that is used to create a laser beam. Also called the cavity.|
|Scanning||Scanning laser beams using a Galvanometer motor or other such device.|
|Second harmonic generation (SHG)||Two times the frequency of a laser fundamental wave or 1/2 the fundamental wavelength. For a YAG laser 1/2 of 1064 nm indicates a wavelength of 532 nm (Green laser).|
|Seed laser||The original light source.|
In short, a laser made using semiconductor material. The activation layer between the p-n junctions generates light when p-side holes combine with n-side electrons.
The semiconductor's crystal (activation layer) amplifies the light and is structured to prevent it from leaking out. Semiconductor lasers are generally used for communications, optical disks, and laser excitation sources.
The structure is very similar to a diode’s. The only difference is the use of GaAs as the host, in which the energy takes the form of light instead of heat, and changes the diode into an LED (light-emitting diode).
|Short pulse laser||Specifies a laser that oscillates at a pulse width of a picosecond or less.
* A picosecond is 1 trillionth of a second (10-12 seconds), and is expressed in PS units.
|Shutter||A light shielding plate used to block the laser beam.|
A method where excitation light is irradiated and energized from the side of the laser medium.
A method of excitation by emitting excitation light from the area surrounding the side of the laser crystal. In this method, it is difficult to transfer heat to the center and heat cannot be transferred evenly to the whole medium.
A laser beam that has been collected to a single point in its cross section and has the characteristics of transverse mode points.
|Solid state laser||A laser oscillator that creates a laser beam by irradiating the laser medium with a lamp, laser diode or other such light source.|
|Spatial mode||A mode where the optical axis of the resonator is in a vertical direction. The cross-section of laser beam power distribution is expressed in single points in single mode, and appears as multiple-peak points in multi-mode.|
A phenomenon where excited atoms are hit with light, inducing photon generation and causing a chain reaction resulting in light emission.
T to Z
|Third harmonic generation (THG)||Three times the frequency of a laser fundamental wave or 1/3 the fundamental wavelength. For a YAG laser 1/3 of 1064 nm indicates a wavelength of 355 nm (UV laser).|
|Threshold||The limit value of a response occurring after energy has been added to a substance. Also known as "Threshold Value".|
|Transverse mode||Can capture the power distribution of light rays emitted from the laser oscillator in cross-section.|
|Ultra-violet light||Non-visible light that has a wavelength shorter than 380 nm. Due to this wavelength being an effective disinfectant, it is used in food and medical related fields.|
Light that is visible to the human eye, measuring in wavelength from 380 nm to 780 nm.
|Wave length||The cyclical length of waves (wave motion) that are transmitted through the air.|
|YAG||Yttrium Aluminum Garnet (Y3Al5O12). One type of solid-state laser medium.
It is often used as an industrial laser and supports marking on metals and plastics.
|YAG laser||A laser that has been oscillated by exciting a YAG crystal doped with an Nd ion using a laser diode or lamp.|
|YVO4||An abbreviation of Yttrium Vanadate (YVO4), a type of medium used for solid-state lasers. Often used with the end pumping method.
Oscillates a fundamental wavelength (1064 nm) laser.
|YVO4 laser||A laser created by exciting an Yttrium Vanadate based YVO4 crystal doped with an Nd ion using an LD or lamp.|
|Znse||Zinc Selenide. Used in CO2 laser lenses because it is an optical crystal that transmits far-infrared rays.|