## AC

In alternating current (AC) the movement of electric charges periodically reverses direction.

## ADC

Analog-to-digital converter.

## CM

Current mode, an operation mode of pyroelectric detectors, especially used in types with integrated operational amplifier, like the LME-335.

## CMOS

Complementary metal-oxide-semiconductor: A technology for constructing integrated circuits.

## D*/D-Star

Specific Detectivity: Figure of merit used to characterize performance, equal to the reciprocal of noise equivalent power (NEP), normalized to square root of unit area and unit bandwidth, see figure.

## DC

In direct current (DC), the flow of electric charge is only in one direction.

## JFET

Junction field effect transistor: special low current and voltage noise transistor for impedance transformation.

## MOEMS

Micro-Opto-Electro-Mechanical Systems: A special kind of Micro-Electro-Mechanical Systems (MEMS) merged with Micro-optics.

## NEP

Noise equivalent power: At a given modulation frequency, operating wavelength and effective noise bandwidth, the NEP is the radiant power that produces a signal-to-noise ratio of unity at the output of the optical detector.

Note: Some manufacturers and authors define NEP as the minimum detectable power per square root bandwidth. When defined this way, NEP has the units of watts per (hertz)1/2. Therefore, the term is a misnomer, because the units of power are watts.

## Rc

Current responivity: short-circuit current of pyroelectric element divided by incident radiant power.

## Rv

Voltage responsivity: output signal voltage divided by incident radiant power.

## TC

Temperature coefficient [%/K or ppm/K].

## urn --> Un

Voltage noise normalized at 1Hz bandwidth, also known as noise density.

## VM

Voltage mode, a conventional operation mode of pyroelectric detectors, for example used in LIE-302.