PIN diode

PIN diode: Acronym for positive-intrinsic-negative diode. A photodiode with a large, neutrally doped intrinsic region sandwiched between p-doped and n-doped semiconducting regions.

Note: A PIN diode exhibits an increase in its electrical conductivity as a function of the intensity, wavelength, and modulation rate of the incident radiation. Synonym PIN photodiode.

Source: from Federal Standard 1037C