© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Ultrafast spin relaxation in quantum-confined structures for all-optical switching

Osamu Wada, Atsushi Tackeuchi, Yuji Nishikawa, Tetsuya Nishimura

Published Jul 7, 1998• 2 citations

Abstract

Electron-spin relaxation has been investigated in a variety of quantum confined structures including GaAs-based quantum wells and quantum wires as well as InP-based quantum wells, and it has been shown to exhibit ultrafast relaxation in the picosecond, and even in the femtosecond, range. This ultrafast relaxation has been used together with the exciton absorption nonlinearity as an novel principle of all-optical switching device which can avoid the speed limit due to the slow carrier lifetime in conventional switching devices. Experiments on GaAs-based quantum-well spin switches have shown 4-ps gate switch operation. Also, experimental analyses have shown the feasibility of these devices at a high contrast ratio (13 dB) and high repetition rate (40 GHz). The application of this device to a demultiplexer has been proposed.

DOI: 10.1117/12.316711

Related papers

Coherent all-optical polarization switching in quantum wells

Eric J. Gansen, K. Jarašiūnas, Scot A. Hawkins +2 more

A coherent all-optical nonlinear polarization switch based on exciton-exciton correlations is demonstrated in a multiple-quantum-well semiconductor structure. A contrast ratio of 8:1 and a relaxation time of less than a picosecond are reported at 80 K using only 10 wells. The results are compared to a similar switch, which makes use of electron spin.

Nonlinear Optics: Materials, Fundamentals, and Applications. Technical Digest. Postconference Edition. TOPS Vol.46 (IEEE Cat. No.00CH37174)•Nov 8, 2002•1 citation

Coherent all-optical polarization switching in quantum wells

Eric J. Gansen, K. Jarašiūnas, Scot A. Hawkins +2 more

A coherent all-optical nonlinear polarization switch based on exciton-exciton correlations is demonstrated in a multiple-quantum-well semiconductor structure. A contrast ratio of 8:1 and a relaxation time of less than a picosecond are reported at 80K using only 10 wells. The results are compared to a similar switch, which makes use of electron spin.

Nonlinear Optics•Jan 1, 2000•0 citations

Ultrafast optical Stark-effect switching and memory actions pumped by transient coherent pulses

Kenji Wada, Hiromichi Horinaka, Nobuyuki Yamamoto +1 more

Since the first experimental demonstrations1,2 of the ultrafast optical Stark effect (OSE) on GaAs-AlGaAs multiple-quantum-well (MQW) excitons, OSE has been attracting investigators' interest because of its potential capability for ultrafast all-optical switching devices. Extensive theoretical3,4 and experimental5 studies were reported heretofore. Recently, however, it has also been recognized that the real excitation inevitably excited by the pump pulse limits the switching repetition speed owing to its long level lifetime (in the nanosecond range).

Quantum Electronics and Laser Science Conference•May 12, 1991•0 citations

All-optical spin-dependent polarization switching in Bragg-spaced quantum well structures

W. J. Johnston, Murat Yıldırım, John P. Prineas +3 more

All-optical polarization switching is demonstrated in a resonant photonic band-gap structure consisting of Bragg-spaced quantum wells (BSQWs). The switch takes advantage of the large spin-dependent optical nonlinearities and the ultrafast recovery present in BSQWs to produce large throughputs (greater than 40%), high contrast ratios (greater than 40 dB), and large optical bandwidths (∼0.6THz), where both switching time and sample recovery time are control-pulse-width limited.

Applied Physics Letters•Sep 1, 2005•35 citations

Coherent all-optical polarization switching based on exciton–exciton interactions in quantum wells

Eric J. Gansen, K. Jarašiūnas, Scot A. Hawkins +2 more

A coherent all-optical nonlinear polarization switch based on exciton–exciton correlations is demonstrated in a multiple-quantum-well semiconductor structure. A contrast ratio of 8:1 and a relaxation time of less than a picosecond are reported at 80 K using only ten wells. The results are compared to a simple phenomenological model to demonstrate that many-body effects are solely responsible for the switching action and that the turn-on and turn-off times are determined by the dephasing time.

Journal of Applied Physics•Aug 1, 2001•4 citations

Experimental demonstration of all-optical 1×2 quantum routing

Byoung Seung HAM

Using a quantum switching technique based on a two-photon coherence swapping, we experimentally demonstrate an all-optical 1×2 quantum routing, where the observed switching time of ∼5μs is two orders of magnitude faster than the carrier lifetime or the population relaxation time. Owing to the nonabsorption resonance and its enhanced nonlinearity, the observed switching efficiency (intensity ratio of switch-out signal to switch-in signal) is as high as 10%. Such an efficient and fast optical routing method has the potential to hyperterahertz all-optical quantum routers, where semiconductor quantum wells or quantum dots are chosen as the optical medium with a spin dephasing time in the range of picoseconds.

Applied Physics Letters•Aug 4, 2004•29 citations

Electron-spin relaxation has been investigated in a variety of quantum confined structures including GaAs-based quantum wells and quantum wires as well as InP-based quantum wells, and it has been shown to exhibit ultrafast relaxation in the picosecond, and even in the femtosecond, range. This ultrafast relaxation has been used together with the exciton absorption nonlinearity as an novel principle of all-optical switching device which can avoid the speed limit due to the slow carrier lifetime in conventional switching devices. Experiments on GaAs-based quantum-well spin switches have shown 4-ps gate switch operation. Also, experimental analyses have shown the feasibility of these devices at a high contrast ratio (13 dB) and high repetition rate (40 GHz). The application of this device to a demultiplexer has been proposed.

Since the first experimental demonstrations1,2 of the ultrafast optical Stark effect (OSE) on GaAs-AlGaAs multiple-quantum-well (MQW) excitons, OSE has been attracting investigators' interest because of its potential capability for ultrafast all-optical switching devices. Extensive theoretical3,4 and experimental5 studies were reported heretofore. Recently, however, it has also been recognized that the real excitation inevitably excited by the pump pulse limits the switching repetition speed owing to its long level lifetime (in the nanosecond range).

Using a quantum switching technique based on a two-photon coherence swapping, we experimentally demonstrate an all-optical 1×2 quantum routing, where the observed switching time of ∼5μs is two orders of magnitude faster than the carrier lifetime or the population relaxation time. Owing to the nonabsorption resonance and its enhanced nonlinearity, the observed switching efficiency (intensity ratio of switch-out signal to switch-in signal) is as high as 10%. Such an efficient and fast optical routing method has the potential to hyperterahertz all-optical quantum routers, where semiconductor quantum wells or quantum dots are chosen as the optical medium with a spin dephasing time in the range of picoseconds.