Mid-Infrared Alₓ In₁₋ₓ Sb Light-Emitting Diodes and Photodiodes for Hydrocarbon Sensing

The properties ofAlₓ In₁₋ₓ Sblight-emitting diodes (LEDs) and photodetectors have been investigated to establish their suitability for methane sensing. Using these components it is possible to achieve good signal-to-noise values at both the characteristic absorption wavelength and also at4~μ m, an attractive wavelength for use as a reference channel. A limit of sensitivity of approximately 400 ppm, with an integration time of 10 s and a path length of 5 cm, was estimated for methane detection