reflection. A mirrorlike reflection at the
wavelength(s) of the incident radiation.
(sr). The unit of measure for a solid angle. There
are 4 Π steradians in a sphere.
equipment. Devices or
enclosures procured specifically for, or modified for, laser test,
calibration, maintenance or other support not part of the laser primary
3.1.54 Transmittance or transmissivity
(τ). The ratio of total transmitted radiant power
to total incident radiant power.
Ultraviolet radiation. Electromagnetic
radiation with wavelengths between soft x-rays and visible radiation. This
region is often broken down into three spectral bands by wavelength: UV-A
(315-400 rim), UV-B (280-315 nm), and UV-C (200-280 rim).
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 400 nm and 700 nm. [Note:
The CIE visible radiation band extends from 400 to 760 nm differing from this
ANSI 2136.1 definition].
Watt (W). The unit of power or radiant flux
equal to one joule-persecond. It is used principally with CW lasers.
3.1.58 Wavelength (λ
). The distance between two points in a periodic
wave which have the same phase is termed one wavelength. The velocity of light
(3 x 10° cm/see) divided by frequency (in Hz) equals wavelength (in