The Sensor Research Laboratory conducts research in miniature directional sound sensors using MEMS, THz imaging using microbolometer focal plane arrays, silicon-based artificial photoreceptors, and multicolor infrared sensors using quantum well structures. Facilities exist for sensor design, packaging and characterization including I-V measurement, Fourier transform infrared spectroscopy, low temperature photocurrent spectroscopy and quantum cascade laser (QCL) sources operating in THz frequencies.
MEMS Directional Sound Sensor
Miniature directional sound sensor based on operational principle of Ormia ochracea fly’s ears (Miles et al., JASA, 1995). Fly uses vibrations of two coupled bars to sense the direction of sound. Sensors mimicking the fly’s ears are being fabricated using micro-electro-mechanical system (MEMS) technology. |
Fly’s hearing organ
Miles JASA, 1995 |
Mechanical equivalent |
Fabricated MEMS sound sensor |
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Video Rate THz Imaging
The penetration of THz radiation through non-metallic materials provides a unique opportunity for detection of concealed objects. The use of uncooled microbolometer technology for THz imaging is being explored with a QCL terahertz laser as an illuminator.
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Microbolometer camera |
Image of a 3.4 THz quantum
cascade laser beam (1 mW) |
Artificial Photoreceptors
A novel approach to detect light is being explored using a silicon-based sensor that can directly convert incident light into a series of electrical impulses similar to biological vision system. The initial experiments carried our using a circuit containing SCR showed such a pulse stream which is sensitive to the light input can be realized. |
Pulse mode sensor circuit
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Measured response to light
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Quantum Well Infrared Sensors
Infrared detectors based on intersubband transition in quantum wells are emerging as an alternative technology to current detectors based on bulk semiconductors and also provides advantages of material selection and mature processing technology. The quantum well structures provide a unique opportunity to fabricate dual-band sensors using interband (as in bulk) and intersubband transitions.
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Pulse mode sensor circuit |
Measured response to light |
