InGaAs diodes

Various eomplete photodiode modules are commereially available. They use Si PIN photodiodes at an internally generated reverse voltage in the range of 30 V, Si avalanche photodiodes at a voltage of 50 to 150 V, or fast InGaAs diodes. 

Wienke, D., Vandenbroek, W., Meissen, W., Buydens, L., Feldhoff, R., Kantimm, T., Huthfehre, T., Quick, L., Winter, F. Cammann, K. (1995) Comparison of an adaptive resonance theory-based neural network (ART- 2A) against other classifiers for rapid sorting of post consumer plastics by remote near-infrared spectroscopic sensing using an InGaAs diode array. Analytica ChimicaActa 317, 1-16. 

NIR spectrometers based on InGaAs diode array have been realized and successfully used for the determination of nitrogen (protein origin) and water content in citrus leaves. Measurement in the 900-1800 nm spectral interval revealed a broad spectral band, with a maximum situated at 1425 nm. This band for fresh whole leaf differs significantly from one for dried powdered leaf due to the abimdant water masking the nitrogen features in the NIR spectrum. 

Wienke, D., et al.. Comparison of an Adaptive Resonance Theory Based on Neural Network (ART-2a) against other Classifiers for Rapid Sorting of Post Consumer Plastics by Remote Near Infrared Spectroscopic Sensing Using an InGaAs Diode Array. AnaZ. Chim. Acta, 1995. 317 1-16. 

V semiconductor material (e.g. InGaAs semiconductor). Very high purity Ga and In are required for the manufacture of semiconductor grade GaAs substrate material and in the deposition of the III—V alloy epilayer structures on these substrates, for example for the manufacture of laser diodes. 

Silicon photodiodes exhibit maximum sensitivity at about 800 nm and they can be used in the whole visible range however their sensitivity drops by several times at the blue region. Special structures can be made with enhanced blue sensitivity (so-called blue or UV diodes). Germanium photodiodes are capable to detect radiation from 600 nm up to 1700 nm. In telecommunication applications InGaAs elements are widely used. 

Figure 24.8 Experimental schematic of the multiplexed diode-laser sensor system used to measure CO, CO2, CH4, and H2O absorption by sampling hot combustion gases 1 ECDL 1.49-1.58 pm 2 optical isolator 3 — fiber coupler 4 — 1x2 fiber splitter 5 — etalon 6 — InGaAs detector 7 — DEB 1.65 pm 8 — 2 x 1 fiber combiner 9 optical fiber 10 fiber pitch 11 — concave mirror 12 — multipass...

Figure 24.14 The left panel is a plan of the testing area near the LENS (reflected shock) tunnel 1 — 8 test section 2 — TDL probe 3 — 4 nozzle M = 8-16 4 — 8" reflected shock tube 5 — fiber optic and signal line conduit 6 — data acquisition and 7 — TDL system optical table. The right panel is a schematic diagram of the setup used to record water-vapor absorption in high-enthalpy flows 1 — InGaAs detectors 2 — tunable diode laser Ai = 1400.74 nm 3 — ring interferometer 4 — tunable diode laser A2 = 1395.69 nm and 5 — HoO reference cell...

Semiconductor (60%) Si, SiGe, GaAs, InGaAs, InP ICs, transistors, solar cells, diodes, etc. Czochralsiki (Cz), Bridgman one melting... 

---