AOI
Angle Of Incidence, see figure.
ARC
Anti-reflection coating is a single or multi layer coating without filter function to improve transmittance of windows or filters.
Cut-on/Cut-off
This is a possible form of specification of the NBP, it is the wavelength at 5 % or 50 % of peak transmission on both flanks (left side Cut-on, right side Cut-off).
CWL
Center wavelength is the center of the pass band of a band pass filter, see figure.
FOV
Here: Field of view of IR detector. It is mostly limited by the detector's aperture hole, see figure.
FSR
Free spectral range: the spacing in optical frequency or wavelength between two successive reflected or transmitted optical intensity maxima or minima of an interferometer.
FWHM
Full width half measure: Another vocable for HPBW.
HPBW
Half power Bandwidth: Bandwidth at 50 % of peak transmittance, see figure.
IR
Infrared: radiation with a wavelength between (0.78 and 1,000) µm.
LWP
Long Wave Pass is a filter with cut-on wavelength but no specification of cut-off. All wavelength longer than cut-on are able to pass, all wavelengths below are blocked. Opposite from SWP (Short Wave Pass), see figure.
MIR
Mid Infrared, radiation with a wavelength between (3 and 50) µm.
NBP
Narrow Band Pass is a band pass filter with a bandwidth of < 10 % of the center wavelength, see figure.
NIR
Near Infrared: Radiation with a wavelength between (0.78 and 3) µm.
UV
Ultraviolet (radiation), see figure.
VIS
Human visible radiation with a wavelength between (0.38 and 0.78) µm.
WBP
Wide Band Pass is a band pass filter with a bandwidth of > 10 % of the center wavelength, see figure.
