Technical Center: Laser Glossary of Terms
Waves are in phase with each other when all the troughs and peaks coincide and are "locked" together. The result is a reinforced wave in increased amplitude (brightness).
Use of the laser beam to heat tissue below vaporization temperatures with the principal objective being to stop bleeding and coagulate tissue.
An instrument which measures luminous intensity.
In quantum theory, the elemental unit of light, having both wave and particle behavior. It has motion, but no mass or charge. The photon energy (E) is proportional to the EM wave frequency (v) by the relationship: E=hv; where h is Planck's constant (6.63 x10-34 Joule-sec).
Chemical substances or medications which increase the sensitivity of the skin or eye to irradiation by optical radiation, usually to UV.
A period of time equal to 10-12 seconds.
A layer of cells at the back of the retina containing pigment granules, i.e., a cloud of charged particles surrounding a laser impact.
Shield The ability of plasma to stop transmission of laser light.
An electro-optical crystal used as a Q-switch.
Ideally, a source with infinitesimal dimensions. Practically, a source of radiation whose dimensions are small compared with the viewing distance.
Beam movement and divergence, due to instability within the laser or other optical distortion.
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.
A state in which a substance has been energized, or excited, so that more atoms or molecules are in a higher excited state than in a lower resting state. This is a necessary prerequisite for laser action.
The rate of energy delivery expressed in watts (joules per second). Thus: 1 Watt = 1 Joule/1 Sec.
An accessory used to measure laser beam power.
A protective housing is a device designed to prevent access to radiant power or energy.
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.
The "on" time of a pulsed laser. It may be measured in terms of millisecond, microsecond, or nanosecond as defined by half-peak-power points on the leading and trailing edges of the pulse.
Operation of a laser when the beam is intermittently on in fractions of a second.
Pulse Repetition Frequency (PRF)
The number of pulses produced per second by a laser.
Laser which delivers energy in the form of a single or train of pulses.
To excite the lasing medium. (See Optical Pumping or Pumping.)
Energized laser medium.
Addition of energy (thermal, electrical, or optical) into the atomic population of the laser medium, necessary to produce a state of population inversion.