Long-Wavelength Quantum Dot Intersubband Optoelectronic Devices
Final progress rept. 1 Jul 1998-30 Jun 2001
MICHIGAN UNIV ANN ARBOR DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
Pagination or Media Count:
While interband transitions in quantum dots have been extensively investigated for long wavelength 1.3 and 1.55 micrometers optical communications, intersubband transitions between the electronic levels formed in the conduction band of the quantum dot have not been widely researched. Since the intersubband energy spacing lies in the mid-infrared 3-20 micrometers range, these transitions can be used for fabricating mid-infrared sources and detectors, which are in great need for applications such as space based infrared imaging, thermal imaging, night vision, thermography for electrical and mechanical fault detection, FTIR spectroscopy and environmental and chemical process monitoring. In this project, intersubband transitions in self-organized InGaAsOaAs quantum dots were investigated and mid-infrared sources and detectors were fabricated. Spontaneous and stimulated emission centered at 13 micrometers, was observed for the first time. We have also fabricated normal incidence quantum dot detectors with very low dark current, high detectivity, and peak responsivity with a photoconductive gain with the highest operating temperature 150K for any normal incidence vertical quantum dot detector.
- Electrooptical and Optoelectronic Devices
- Quantum Theory and Relativity