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A novel approach towards two-photon absorption based detectors

Krug, T. and Folliot, H. and Lynch, Michael and Bradley, Ann Louise and Donegan, John Francis and Barry, Liam P. and Roberts, J.S. and Hill, G. (2003) A novel approach towards two-photon absorption based detectors. In: CLEO 2003 - Conference on Lasers and Electro-Optics Europe, 1-6 June 2003.

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Summary: We have demonstrated that the inherent inefficiency of the TPA process in semiconductors can be overcome by incorporating the semiconductor in a microcavity structure. Proof of concept devices with a 0.27μm Ga0.7Al0.3As active region and two Bragg reflectors with the cavity resonance of 890 nm were fabricated. We measured the TPA photocurrent of these devices and have demonstrated a factor of 12000 enhancement over a nonmicrocavity device at 890 nm. Our active length of 0.27 nm is as efficient as 5.4 mm without a microcavity, overcoming the very long detector lengths limiting the use of TPA in practical autocorrelators, optical switches and sampling devices for real telecommunication systems. The effect of the cavity is to enhance the intra-cavity optical intensity, which leads to an increase in the nonlinear response of the active region. We studied, theoretically and experimentally, the impact of the cavity on the temporal response and the sensitivity of the device, which are critical considerations for commercial applications. This cavity design has a 3 pico-second response time and the autocorrelation trace is comparable with the BBO crystal response for an input 1.6 ps pulse. Devices designed for 1550 nm have also been realised and our measurements indicate these two-photon absorption based detectors are potential candidates for optical autocorrelation of short optical pulses, and for optical switching and sampling in optical time division multiplexed (OTDM) communications systems.

Item Type:Conference or Workshop Item (Paper)
Event Type:Conference
Subjects:Engineering > Optical communication
Physical Sciences > Semiconductors
DCU Faculties and Centres:DCU Faculties and Schools > Faculty of Engineering and Computing > School of Electronic Engineering
Research Initiatives and Centres > Research Institute for Networks and Communications Engineering (RINCE)
Publisher:Institute of Electrical and Electronics Engineers
Official URL:
Copyright Information:©2003 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
ID Code:2291
Deposited On:16 Jan 2009 15:57 by DORAS Administrator. Last Modified 05 Mar 2009 15:54

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