Sensors and Electron Devices Directorate Research Areas

Quantum Well Infrared Technology

Advisor: Choi, Kwong-Kit (kwongkit.choi@us.army.mil 301-394-0495)
Keywords: Nanosensors; Voltage tunable sensors; Photonic crystal ICs; Spectrometers; Focal plane arrays

Based on the mature III-V material capability, quantum well infrared technology has been developed rapidly. Large format long wavelength focal plane arrays up to 1024 x 1024 pixels have been demonstrated in our laboratory. Even larger format FPAs with advanced detection functionality are being developed. Research opportunities range from basic physics to array production and demonstration. In particular, we are developing fabrication processes to produce FPAs with 2048 x 2048 pixels, which will be integrated with advanced features such as voltage tunable two-color detection, adaptive multicolor detection, and polarization-sensitive detection. To achieve these capabilities, fundamental physics, such as hot-electron dynamics, electron transfer in QWs, QW band structures, and near-field electromagnetic phenomena, are currently being studied.

Besides these near- and mid-term projects, long-term research projects are also of interest. In the nanosensor project, research is conducted to fabricate nanoscaled sensors and to study their optoelectronic properties. The objective is to produce the smallest functioning infrared sensor for molecular electronics. In the photonic crystal QWIP integrated circuit project, photonic bandgap structures are fabricated into the QWIP materials. The embedded QWIP detectors are used for the study of the wave guiding and scattering effects of photonic crystals. The objectives are to integrate the ICs with quantum cascade lasers for free space transceiver applications and for chemical sensing applications. Research opportunities in these areas include nanofabrication, low-dimensional physics, electromagnetic phenomena in photonic crystals, and device fabrication and demonstration.

References
Choi KK, et al: Proceedings of SPIE 6542: 65420S, 2007
Choi KK, et al: Proceedings of SPIE 7082: 708208, 2008