Laser Glossary

Laser Fundamentals

Laser

  • Meaning: Light Amplification by Stimulated Emission of Radiation

  • Example: A device that generates a coherent beam of light through stimulated emission

Active Medium

  • Meaning: The material in a laser that emits light when excited

  • Example: CO2 gas in a CO2 laser, or neodymium-doped crystal in an Nd:YAG laser

Optical Cavity

  • Meaning: The space between mirrors where laser light is amplified

  • Example: The tube containing gas in a CO2 laser

Pump Source

  • Meaning: Energy source that excites the active medium

  • Example: Electrical discharge in a gas laser, or flashlamp in a solid-state laser

 

Laser Types

CO2 Laser

  • Meaning: A gas laser using carbon dioxide as the active medium

  • Example: Commonly used for cutting and engraving non-metallic materials

Fiber Laser

  • Meaning: Laser where the active medium is an optical fiber doped with rare-earth elements

  • Example: Ytterbium-doped fiber laser used for metal cutting and welding

Diode Laser

  • Meaning: Semiconductor laser that directly converts electrical energy into light

  • Example: Used in laser pointers and as pump sources for other lasers

Nd:YAG Laser

  • Meaning: Solid-state laser using neodymium-doped yttrium aluminum garnet crystal

  • Example: Used in materials processing and medical applications

 

Laser Properties

Wavelength

  • Meaning: The distance between successive crests of the laser wave

  • Example: 10.6 μm for a CO2 laser, 1064 nm for an Nd:YAG laser

Power

  • Meaning: The rate at which energy is emitted by the laser

  • Example: 100 W continuous wave laser for cutting thin materials

Pulse Duration

  • Meaning: The length of time for a single laser pulse

  • Example: Nanosecond pulses for laser marking, femtosecond pulses for ultra-precise machining

Beam Quality

  • Meaning: A measure of how well a laser beam can be focused

  • Example: M² (M-squared) value, with M²=1 being ideal

 

Laser Optics

Focal Length

  • Meaning: Distance from a lens to its focal point

  • Example: 50 mm focal length lens for focusing a laser beam

Beam Divergence

  • Meaning: The angle at which the laser beam spreads

  • Example: 1 mrad divergence for a well-collimated laser beam

Beam Expander

  • Meaning: Optical system that increases the diameter of a laser beam

  • Example: Used to reduce beam divergence or increase spot size

 

Laser Processing

Cutting

  • Meaning: Using a laser to separate materials

  • Example: Cutting sheet metal with a fiber laser

Engraving

  • Meaning: Using a laser to create marks or designs on a surface

  • Example: Engraving logos on products with a CO2 laser

Welding

  • Meaning: Joining materials using a laser beam

  • Example: Welding car body parts in automotive manufacturing

Marking

  • Meaning: Creating permanent marks on materials with a laser

  • Example: Marking serial numbers on electronic components

Laser Trimming

  • Meaning: Laser trimming is a precision process using a laser beam to remove small amounts of material from a component, typically fine-tuning electrical or mechanical properties.

  • Examples: Trimming of excessive material from radial shaft seals outer and inner diameters.

Laser Micro-structuring

  • Meaning: Laser micro-structuring is a technique that uses laser beams to create precise, microscale patterns or structures on material surfaces, often to impart specific functional properties.

  • Examples: Creating micro-textures on metal surfaces to reduce friction and improve tribological properties

 

Laser Safety

Laser Safety Officer (LSO)

  • Meaning: Person responsible for overseeing laser safety in a facility

  • Example: An LSO implementing safety protocols in a manufacturing plant

Personal Protective Equipment (PPE)

  • Meaning: Safety gear worn to protect against laser hazards

  • Example: Laser safety goggles with appropriate optical density for the laser wavelength

Nominal Hazard Zone (NHZ)

  • Meaning: Area where laser radiation exceeds the maximum permissible exposure

  • Example: Defining the NHZ around a laser cutting machine

 

Laser Safety Classes

Class 1

  • Meaning: Lasers that are safe under reasonably foreseeable conditions of operation

  • Example: Laser printers, CD players

Class 1M

  • Meaning: Lasers that are safe for the naked eye, but may be hazardous if viewed with optical instruments

  • Example: Some laser diodes used in fiber optic communication systems

Class 2

  • Meaning: Visible lasers (400-700 nm) that are safe for accidental viewing but potentially hazardous for deliberate staring

  • Example: Laser pointers, barcode scanners

Class 2M

  • Meaning: Visible lasers that are safe for accidental viewing but may be hazardous if viewed with optical instruments

  • Example: Some laser light show projectors

Class 3R

  • Meaning: Lasers that are potentially hazardous under some direct viewing conditions, but with a lower risk than Class 3B

  • Example: Some laser measuring tools, laser gun sights

Class 3B

  • Meaning: Lasers that are hazardous for direct beam viewing and specular reflections, but generally not for diffuse reflections

  • Example: Many research lasers, some laser light shows

Class 4

  • Meaning: High-power lasers that are hazardous for direct viewing, specular and diffuse reflections, and can cause fires

  • Example: Surgical lasers, industrial cutting lasers

Nominal Hazard Zone (NHZ)

  • Meaning: The space within which the level of direct, reflected, or scattered radiation may exceed the applicable MPE

  • Example: The area around a Class 4 laser where protective measures are required

Maximum Permissible Exposure (MPE)

  • Meaning: The highest level of laser radiation to which a person may be exposed without hazardous effects or biological changes

  • Example: For visible lasers, 25.4 W/m² for 0.25 seconds of exposure

Optical Density (OD)

  • Meaning: A measure of the attenuation provided by laser protective eyewear

  • Example: OD 5 eyewear blocks 99.999% of incident laser light

 

Laser Machine Components

Laser Source

  • Meaning: The device that generates the laser beam

  • Example: CO2 laser tube, fiber laser module, or diode laser

Beam Delivery System

  • Meaning: Components that guide the laser beam from the source to the workpiece

  • Example: Mirrors, lenses, fiber optics

Motion System

  • Meaning: Mechanical components that move the laser beam or workpiece

  • Example: Gantry, linear stages, rotary axes

Control System

  • Meaning: Electronics and software that manage machine operations

  • Example: CNC controller, user interface, motion control software

 

Laser Machine Installation Terminology

Footprint

  • Meaning: The floor space required for the laser machine

  • Example: A 4' x 8' area needed for a medium-sized laser cutter

Utilities

  • Meaning: Services required to operate the laser machine

  • Example: Electrical power, compressed air, water cooling, exhaust ventilation

Laser Safety Enclosure

  • Meaning: A protective housing that contains the laser radiation

  • Example: Class 1 enclosure that prevents laser exposure during operation

Beam Path

  • Meaning: The route the laser beam travels from source to workpiece

  • Example: A series of mirrors and lenses that direct the beam to the cutting head

 

Safety and Compliance

Laser Safety Officer (LSO)

  • Meaning: Person responsible for overseeing laser safety in a facility

  • Example: An LSO implementing safety protocols and training programs

Nominal Hazard Zone (NHZ)

  • Meaning: Area where laser radiation exceeds the maximum permissible exposure

  • Example: Defining the NHZ around a high-power laser cutting machine

Interlocks

  • Meaning: Safety devices that prevent accidental exposure to laser radiation

  • Example: Sensors that shut off the laser when access panels are opened