AAT	atomic axial tensor
APT	atomic polar tensor
CD	circular dichroism
DC	direct current (non-oscillating signal)
DFT	density functional theory
FF	force field
FT	Fourier transform
IR	infrared
InSb	indium antimonide
MCT	mercury cadmium telluride
MVCD	magnetic vibrational circular dichroism
ORD	optical rotatory dispersion
PEM	photo elastic modulator
PMT	photo multiplier tube
QCL	quantum cascade laser
QM	quantum mechanical
S/N	signal to noise ratio
UV	ultraviolet
VCD	vibrational circular dichroism