Ge-based spin-photodiodes have been employed to investigate the spectral dependence of optical spin orientation in germanium, in the range 400-1550 nm. We found the expected maximum in the spin polarization of photocarriers for excitation at the direct gap in Gamma (1550 nm) and a second sizable peak due to photogeneration in the L valleys (530 nm). Data suggest distinct spin depolarization mechanisms for excitation at Gamma and L, with shorter spin relaxation times whether the X point is involved. These devices can be used as integrated photon-helicity detectors over a wide spectral range.
Wide-range optical spin orientation in Ge from near-infrared to visible light
Manzoni C;Cerullo G;
2014
Abstract
Ge-based spin-photodiodes have been employed to investigate the spectral dependence of optical spin orientation in germanium, in the range 400-1550 nm. We found the expected maximum in the spin polarization of photocarriers for excitation at the direct gap in Gamma (1550 nm) and a second sizable peak due to photogeneration in the L valleys (530 nm). Data suggest distinct spin depolarization mechanisms for excitation at Gamma and L, with shorter spin relaxation times whether the X point is involved. These devices can be used as integrated photon-helicity detectors over a wide spectral range.File in questo prodotto:
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