Quantum Well Infrared Photodetectors (QWIP)

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Quantum Well Infrared PhotodetectorsUnderstanding climate changes and the parameters influencing the climate is very important. Infrared imaging is an important technology for gathering useful information however, prior to 1990, no photodetector arrays had been fabricated that would operate at infrared wavelengths necessary for detecting these changes in ecosystems. In a unique collaboration between the Goddard Space Flight Center, and ATT/Bell Labs the first quantum well photodetector array capable of operating in the far infrared was developed and incorporated into a camera system that successfully performed airborne imaging. Dr. Sarath Gunapala of the Jet Propulsion Laboratory (JPL), while working with Dr. Barry Levine at Bell Labs, helped developed the QWIP technology that could be used in imaging systems. 

Bell Labs decided that this novel technology did not fit their commercial directions. However, technical visionaries at NASA JPL saw its potential for producing enhanced space-based imaging systems and acquired the technology as well as several technical people including Dr. Gunapala. At JPL he and his colleagues have perfected the QWIP technology and have produced cameras that are capable of operating at infrared wavelengths that were not previously possible with existing technology. Use of this technology is enabling NASA to enhance substantially its earth? observation capability. The QWIP technology is a complicated solid-state detector that involves sandwiching gallium arsenide chips between silicon wafers and connected them with indium connectors. The technology can be designed to operate at longer infrared wavelengths and can be produced at lower costs making it is superior to any existing technology. A new company, QWIP Technologies, was formed to obtain a license from JPL to produce focal plane cameras using the QWIP technology. 

OmniCorder, a biomedical company, recognized the potential of using QWIP technology for medical purposes. They obtained an exclusive, worldwide license from NASA to use the technology for biological applications, including breast cancer detection. Recent medical research studies have shown that cancer cells exude nitric oxide. This causes changes in blood flow and concomitantly the temperature in tissue surrounding cancer. The OmniCorder BioScan System, which incorporates the QWIP technology, is able to reliably detect these minute temperature changes. The system, which has received FDA approval, uses no ionizing radiation and permits a hazard-free non-invasive assessment of abnormal tissue.