InGaAsArrays

InGaAsArrays are two-dimensional photodetector arrays constructed from indium gallium arsenide (InxGa1−xAs) and optimized for near-infrared imaging and sensing. By adjusting the indium content, the spectral response can be tuned, with lattice-matched In0.53Ga0.47As grown on indium phosphide (InP) substrates forming the common platform for detectors in the 1.0 to 1.7 micrometer range. These arrays typically implement p–n or p–i–n photodiodes integrated with readout circuitry to form focal plane arrays.

Manufacturing methods include metal-organic chemical vapor deposition (MOCVD) and liquid-phase epitaxy (LPE) for the active InGaAs layers, often combined with surface passivation and antireflection coatings. The arrays come in linear and two-dimensional formats, with pixel pitches commonly in the 15–25 micrometer range and array sizes from a few hundred to several thousand pixels (for example 256×256 or 512×512).

Spectrally, InGaAs detectors cover about 0.9–1.7 micrometers, enabling telecom-grade operation around 1.3 and 1.55 micrometers; some variants extend toward 2 micrometers with modified compositions or substrates. Performance depends on temperature, bias, and device design; dark current and noise increase with temperature, so cooling with thermoelectric coolers is typical for high-sensitivity applications. Responsivity and quantum efficiency are high within the designed band.

Applications include infrared imaging for defense and security, industrial monitoring, scientific instrumentation, and optical communications receivers. InGaAs arrays are favored for their mature fabrication on InP, compatibility with fiber-optic systems, and robust performance in the near-infrared.