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Physical Sciences and Mathematics Commons

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Physics

University of Massachusetts Boston

Series

2001

Laser transitions

Articles 1 - 1 of 1

Full-Text Articles in Physical Sciences and Mathematics

Sige/Si Thz Laser Based On Transitions Between Inverted Mass Light-Hole And Heavy-Hole Subbands, L. Friedman, Greg Sun, Richard A. Soref Jan 2001

Sige/Si Thz Laser Based On Transitions Between Inverted Mass Light-Hole And Heavy-Hole Subbands, L. Friedman, Greg Sun, Richard A. Soref

Physics Faculty Publications

We have investigated a SiGe/Si quantum-well laser based on transitions between the light-hole and heavy-hole subbands. The lasing occurs in the region of k space where the dispersion of ground-state light-hole subband is so nonparabolic that its effective mass is inverted. This kind of lasing mechanism makes total population inversion between the two subbands unnecessary. The laser structure can be electrically pumped through tunneling in a quantum cascade scheme. Optical gain as high as 172/cm at the wavelength of 50 μm can be achieved at the temperature of liquid nitrogen, even when the population of the upper laser subband is …