An ultra fast quantum well infrared photodetector

Quantum well infrared photodetectors (QWIP) are intrinsically very high speed devices that usually are limited in response speed by the external circuitry. An ultra fast QWIP has been developed that integrates a QWIP mesa with an integrated co-planar waveguide to cable transition. Devices packaged with both K connectors and V connectors have been assembled and tested. At DC the devices demonstrate optical heterodyne efficiency of 90% or greater. Optical heterodyne measurements using CO2 lasers have shown that with a K connector, response is flat ±10% up to 40 GHz and then drops rapidly due to the cable. Using a V connector, heterodyne efficiency of 50% of ideal has been measured at 56 GHz and 25% at 74 GHz.