Resonant-cavity-enhanced photodetectors and LEDs in the mid-infrared

In this paper we outline the use of resonant-cavity enhancement for increasing the exterior coupling efficiency of photodetectors and light-emitting diodes (LEDs) in the mid-infrared (MIR) spectral region. This method is potentially very important in the MIR because encapsulation is not presently feasible due to the lack of suitable materials. Among other potential applications, resonant-cavity-enhanced (RCE) photodetectors and LEDs could be particularly suitable for greenhouse gas detection because of their ‘pre-tunable’ spectrally narrowed resonantly enhanced peaks. We also present the optical characterization of an InAs RCE photodetector aimed at the detection of methane gas View the MathML source, and an InAs/InAs0.91Sb0.09 resonant-cavity LED (RCLED) aimed at carbon dioxide gas View the MathML source. The high peak responsivity of the RCE photodetector was View the MathML source at View the MathML source, and the RCLED peaked at View the MathML source. These are among the longest operating wavelengths for III–V RCE photodetectors and RCLEDs reported in the literature.