OSHA Laser Safety Terms- Questions and
Answers| Latest Update
Optical Fiber A filament of quartz or other optical material capable of transmitting light
along its length by multiple internal reflection and emitting it at the end.
Optical Pumping The excitation of the lasing medium by the application of light rather
than electrical discharge.
Optical Radiation Ultraviolet, visible, and infrared radiation (0.35-1.4 µm) that falls in the
region of transmittance of the human eye.
Output Power The energy per second measured in watts emitted from the laser in the form
of coherent light.
Power The rate of energy delivery expressed in watts (Joules per second). Thus: 1 Watt =
1 Joule x 1 §
Protective Housing A protective housing is a device designed to prevent access to radiant
power or energy.
Pulse A discontinuous burst of laser, light or energy, as opposed to a continuous beam. A
true pulse achieves higher peak powers than that attainable in a CW output.
, Pulse Duration The "on" time of a pulsed laser, it may be measured in terms of
milliseconds, microseconds, or nanoseconds as defined by half-peak-power points on the leading
and trailing edges of the pulse.
Pulsed Laser Laser which delivers energy in the form of a single or train of pulses.
Pump To excite the lasing medium.
Pumped Medium Energized laser medium.
Pumping Addition of energy (thermal, electrical, or optical) into the atomic population of
the laser medium, necessary to produce a state of population inversion.
Radiant Energy (Q) Energy in the form of electromagnetic waves usually expressed in
units of Joules (watt-seconds).
Radiant Exposure (H) The total energy per unit area incident upon a given surface. It is
used to express exposure to pulsed laser radiation in units of J/cm2.
Reflection The return of radiant energy (incident light) by a surface, with no change in
wavelength.
Refraction The change of direction of propagation of any wave, such as an
electromagnetic wave, when it passes from one medium to another in which the wave velocity is
Answers| Latest Update
Optical Fiber A filament of quartz or other optical material capable of transmitting light
along its length by multiple internal reflection and emitting it at the end.
Optical Pumping The excitation of the lasing medium by the application of light rather
than electrical discharge.
Optical Radiation Ultraviolet, visible, and infrared radiation (0.35-1.4 µm) that falls in the
region of transmittance of the human eye.
Output Power The energy per second measured in watts emitted from the laser in the form
of coherent light.
Power The rate of energy delivery expressed in watts (Joules per second). Thus: 1 Watt =
1 Joule x 1 §
Protective Housing A protective housing is a device designed to prevent access to radiant
power or energy.
Pulse A discontinuous burst of laser, light or energy, as opposed to a continuous beam. A
true pulse achieves higher peak powers than that attainable in a CW output.
, Pulse Duration The "on" time of a pulsed laser, it may be measured in terms of
milliseconds, microseconds, or nanoseconds as defined by half-peak-power points on the leading
and trailing edges of the pulse.
Pulsed Laser Laser which delivers energy in the form of a single or train of pulses.
Pump To excite the lasing medium.
Pumped Medium Energized laser medium.
Pumping Addition of energy (thermal, electrical, or optical) into the atomic population of
the laser medium, necessary to produce a state of population inversion.
Radiant Energy (Q) Energy in the form of electromagnetic waves usually expressed in
units of Joules (watt-seconds).
Radiant Exposure (H) The total energy per unit area incident upon a given surface. It is
used to express exposure to pulsed laser radiation in units of J/cm2.
Reflection The return of radiant energy (incident light) by a surface, with no change in
wavelength.
Refraction The change of direction of propagation of any wave, such as an
electromagnetic wave, when it passes from one medium to another in which the wave velocity is
