Simulation of a high-speed demultiplexer based on two-photon absorption in semiconductor devices

In this paper, we present a theoretical model of an all-optical demultiplexer based on two-photon absorption in a specially designed semiconductor micro-cavity for use in an optical time division multiplexed system. We show that it is possible to achieve error-free demultiplexing of a 250 Gbit/s OTDM signal (25 × 10 Gbit/s channels) using a control-to-signal peak pulse power ratios of around 30:1 with a device bandwidth of approximately 30 GHz

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

A highly-efficient optical sampling system based on Two-Photon Absorption in a semiconductor micro-cavity is presented. The sensitivity of the sampling system is calculated to be 0.1mW² with a temporal resolution of 2ps

Design and fabrication of highly efficient non-linear optical devices for implementing high-speed optical processing

We present the design and fabrication of micro-cavity semiconductor devices for enhanced Two-Photon-Absorption response, and demonstrate the use of these devices for implementing sensitive autocorrelation measurements on pico-second optical pulses

High-sensitivity two-photon absorption microcavity autocorrelator

A GaAs-AlAs microcavity device has been used as a photodetector in an autocorrelator for measuring the temporal pulsewidth of 1.5-/spl mu/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/spl times/10/sup -4/ (mW)/sup 2/, which represents two orders of magnitude improvement when compared with conventional autocorrelators

Two-photon absorption in microcavities for optical autocorrelation and sampling

We have designed novel semiconductor microcavity structures for the enhancement of the two-photon absorption (TPA) photocurrent. We report a TPA autocorrelation technique for short optical pulses that uses the microcavity structure instead of a second harmonic generation crystal. Knowledge of these characteristics is important for implementation in applications such as optical switching and sampling in optical time division multiplexed (OTDM) communications systems

A novel approach towards two-photon absorption based detectors

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

Two-photon-induced photoconductivity enhancement in semiconductor microcavities: a theoretical investigation

We describe a detailed theoretical investigation of two-photon absorption photoconductivity in semiconductor microcavities. We show that high enhancement (by a factor of >10, 000) of the nonlinear response can be obtained as a result of the microcavity effect. We discuss in detail the design and performance (dynamic range, speed) of such a device with the help of the example of an AlGaAs/GaAs microcavity operating at 900 nm. This device shows promise for low-intensity, fast autocorrelation and demultiplexing applications

Resonance tuning of two-photon absorption microcavities for wavelength-selective pulse monitoring

We show the potential use of a single photodetector for multichannel pulse monitoring. Two-photon absorption in a microcavity structure is used as the nonlinear optical technique for pulse monitoring. Angle tuning of the device allows the resonance to be tuned. For the device studied here that is optimized for 2-ps pulses, a possible tuning range of 55 nm is shown

Optical signal processing via two-photon absorption in a semiconductor microcavity for the next generation of high-speed optical communications network

Due to the introduction of new broadband services, individual line data rates are expected to exceed 100 Gb/s in the near future. To operate at these high speeds, new optical signal processing techniques will have to be developed. This paper will demonstrate that two-photon absorption in a specially designed semiconductor microcavity is an ideal candidate for optical signal processing applications such as autocorrelation, sampling, and demultiplexing in high-speed wavelength-division-multiplexed (WDM) and hybrid WDM/optical time-division-multiplexed networks

Chromatic dispersion monitoring of 80-Gb/s OTDM data signal via two-photon absorption in a semiconductor microcavity

In this letter, a novel method of chromatic dispersion monitoring via two-photon absorption (TPA) is investigated. A specially designed semiconductor microcavity is employed as a TPA detector for monitoring data signals operating at rates up to 80Gb/s. As the microcavity has a wavelength-dependent response, a single device can be used to monitor multiple channels in a multiwavelength optical telecommunication syste