High-Sensitivity Two-Photon Absorption Microcavity Autocorrelator

Abstract

Abstract-A GaAs-AlAs microcavity device has been used as a photodetector in an autocorrelator for measuring the temporal pulsewidth of 1.5-m optical pulses. Enhancement of the two-photon absorption photocurrent due to the microcavity structure results in an autocorrelation (average power times peak power) sensitivity of 9 3 10 4 (mW) 2 , which represents two orders of magnitude improvement when compared with conventional autocorrelators.

Evolution of Optical Sampling

“…The main difficulty with using TPA for highspeed optical sampling is its inherent inefficiency, which means that such systems either require high optical intensities or very long detectors, making them unsuitable for practical telecommunications applications. One possible way to overcome this efficiency problem is to employ a semiconductor microcavity (Krug et al, 2004), which should significantly enhance the TPA response of the device, and enable the implementation of a practical sampling element for high-speed optical systems.…”

All-optical sampling utilising two-photon absorption in semiconductor microcavity

“…The front pdoped mirror consists of 9 pairs while the back n-doped mirror consists of 18 pairs designed for reflectivity at 1550nm. The device studied was a 100µm diameter vertical structure [3]. Fig.…”

Simple Autocorrelation Measurement by Using a GaP Photoconductive Detector

“…Several groups have demonstrated that TPA or 3PA based processes can be effective for pulse diagnostics in the femtosecond and picosecond time range with photodiodes using Si [2,3], GaAsP [2,[4][5][6][7], InGaAs [8], SiC [9,10], ZnSSe [11], GaN [12], light-emitting diodes using AlGaAs [13], laser diodes using GaAsP [3], GaAs/AlGaAs [14], GaN [15] and photocathodes using CsI and CuI PMTs [16] in autocorrelator schemes. Other semiconductor waveguides and microcavity structure devices were also developed [17][18][19]. Semiconductor sensors offer high sensitivity and ease of use in compact integrated solid-state devices which are insensitive to frequency chirp and polarization.…”