Thermography camera tuned to detect absorption of infrared radiation in a selected spectral bandwidth

摘要

An infrared camera system is provided to detect absorption of infrared radiation in a selected spectral bandwidth. In one example, an infrared camera system includes a lens adapted to receive infrared radiation from a survey scene comprising one or more gasses. The infrared camera system also includes a focal plane array comprising a plurality of quantum well infrared photo detectors (QWIPs). The QWIPs are tuned to detect a limited spectral bandwidth of the infrared radiation corresponding to at least a portion of an infrared absorption band of the one or more gasses. The infrared camera system also includes an optical band pass filter positioned substantially between the lens and the focal plane array. The optical band pass filter is adapted to filter the infrared radiation to a wavelength range substantially corresponding to the limited spectral bandwidth of the QWIPs before the infrared radiation is received by the focal plane array.

主权项

1. A device comprising:
a focal plane array comprising a plurality of infrared photo detectors, wherein each infrared photo detector comprises: a plurality of quantum well layers configured to generate a desired photocurrent in response to infrared radiation; and a plurality of barrier layers alternating with the quantum well layers, wherein an amount of doping of the quantum well layers, a spacing of quantum wells in the quantum well layers, and thicknesses of the quantum well layers and the barrier layers are selected to tune the focal plane array to have a limited spectral bandwidth with a peak response within a wavelength range of 10.3 μm to 10.8 μm and a full width half maximum spectral bandwidth of less than 0.7 μm in response to the infrared radiation, and wherein the less than 0.7 μm spectral bandwidth of the focal plane array is selected to reduce signal noise substantially outside the wavelength range of 10.3 μm to 10.8 μm associated with operation of the focal plane array and/or an optical band pass filter.