NOISE MEASUREMENT OF III-V COMPOUND DETECTORS FOR 2 μm LIDAR/DIAL REMOTE SENSING APPLICATIONS

Noise of a photodetector plays a vital role in determining the minimum detectable signal for lidar and DIAL receivers. A low noise trans-impedance amplifier circuit has been employed to examine the noise of III-V compound infrared detectors. These infrared detectors include InGaAs PIN diodes and newly developed InGaAsSb avalanche photodiodes (APDs) with separate absorption and multiplication (SAM) structure. The noise of these detectors are compared with well-established Si APDs. These measured noises are utilized to compute the figures-of-merit, such as noise-equivalent-power (NEP) and detectivity (D*) of these devices and are presented in this paper.