Translator Disclaimer
24 May 1999 Novel technique for all-optical modulation in asymmetric quantum wells
Author Affiliations +
Modulators based on interband (IB) light absorption by intersubband (ISB) excitations in undoped quantum well structures (QWs) has the inherent advantage of ultrafast response without thermal dissipation at high bit rates. In this report we present an efficient scheme to achieve ultrafast modulation in the femtosecond regime using IB and ISB light pulses in a step-like type II semiconductor QW. The threshold control-light intensity for 100% modulation in the proposed structure is less than 1 pJ, which is at least an order of magnitude lower than in any excitonic optical switch proposed until now. The peak modulation efficiency in asymmetric QW's at 1 MW/cm2 is 40% which is twice than that estimated in symmetric QW's and can be enhanced to 100% at 10 MW/cm2. A modulation speed of 500 fs can be achieved without any serious degradation of the IB signal due to thermal dissipation. This is an important step towards the development of novel ultrafast optoelectronic devices based on the pulse shaping techniques.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Arup Neogi, Haruhiko Yoshida, Teruo Mozume, Osamu Wada, and Hitoshi Kawaguchi "Novel technique for all-optical modulation in asymmetric quantum wells", Proc. SPIE 3624, Ultrafast Phenomena in Semiconductors III, (24 May 1999);

Back to Top