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The effect of two-photon absorption (TPA) on all-optical logic operation in quantum-dot semiconductor optical amplifier (QD-SOA) has been carried out. We model the rate equation with the TP...

We investigate all-optical logic operation in quantum-dot semiconductor optical amplifier (QD-SOA) based Mach–Zehnder interferometer considering the effects of two-photon absorption (TPA). TPA occu...

A wavelength-division multiplexing/time-division multiplexing (WDM/TDM) network exploiting the broad wavelength range of T-band (1000–1260 nm) is proposed. The network is based on different wavebands of downlink and uplink channels, with each transmitter consisting of a wavelength tunable laser utilized for more than one user through wavelength tuning. The downlink section of the network also introduces interconnecting optical lines and semiconductor optical amplifiers (SOAs), pairing up each of the downlink wavebands to provide structural redundancy by allowing transmitters to be shared between the paired wavebands through TDM. Quantum dot (QD)-based wavelength tunable lasers and SOAs were fabricated for a preliminary demonstration experiment. Error-free transmission with less than 1 dB of power penalty was obtained for a wavelength range of 24.2 nm (5.6 THz). The QD-SOAs exhibited a decent rise and fall time, as well as extinction ratios throughout the wavelength range, which enable it to be used as path switches.

We realize a multiple-input all-optical OR gate by cascading logic gates based on quantum-dot semiconductor optical amplifier (QD-SOA). We demonstrate that it can be implemented by three QD-SOAs.

Storage and manipulation of quantum information requires (nearly) perfect timing---or precisely timed pulse sequences, anyhow. In quantum memory based on photon echoes, for example, the appearance time of the echo must be determined with great accuracy. This study shows how to control photon echoes in a quantum-dot optical amplifier operating at room temperature. As the amplifier is a distributed device, propagation effects are dominant in the generation of the echo pulse, and shaping the excitation pulse serves to control the echo's appearance time and strength.

The polarization independent SOA module for T-band communication was fabricated using the quantum dot gain chip and the polarization diversity circuits with photonic crystal waveplates. The polarization dependent gain was successfully reduced to 0.5 dB.

We demonstrate simultaneous four-channel wavelength conversion of 50-Gbit/s non-return-to-zero differential quadrature-shift-keying signals with a channel spacing of 100-GHz using a quantum-dot semiconductor optical amplifier. Error-free operations with low-power penalties are successfully achieved with various channel configurations.

We experimentally investigate the phase-sensitive amplification characteristics in quantum-dot semiconductor optical amplifier. Phase-sensitive dynamic ranges (PSDRs) of ∼3dB and ∼11dB are obtained for degenerate and non-degenerate components, respectively, with 5-dBm total launch power.

Time-resolved gain and phase dynamics of an InAs/InGaAsP/InP quantum-dot semiconductor optical amplifier are investigated. The recovery is dominated by an ultrafast component (~1 ps), indicating strongly that the gain medium is genuinely dot-like in character.

Ultra linear quantum-dot semiconductor optical amplifiers at 1.3 mum provide high dynamic input power range for single and multiple channels with error-free amplification. Good burst-mode tolerance is observed.

Slow light in the absorption regime and fast light in the gain regime are demonstrated in 1.55 μm quantum-dot semiconductor optical amplifiers at room temperature for both ground state and excited state.

We demonstrate for the first time the low penalty cascaded performance of a 1.3mum QD SOA. Eleven passes are feasible for 10Gb/s data while maintaining a Q-factor exceeding 6 for filter-free operation.

A highly efficient non-degenerate four-wave mixing (FWM) process using CW pump and probe signals around the L-band wavelength range in an InAs/InGaAsP quantum dot semiconductor optical amplifier (QD-SOA) is experimentally demonstrated for the first time. The preliminary experimental results indicate that the FWM efficiency using QD-SOA is independent of the sign of the frequency detuning and decreases by less than 20 dB/decade with frequency detuning increasing.

The outstanding features of Quantum Dot Semiconductor Optical Amplifiers (QD-SOA’s) such as all-optical signal processing and signal regeneration are caused them are widely used in the optical communication systems. Due to the nano structure of these amplifiers, accurate design and modelling of them is a complex and challenging problem. This paper addresses design a QD-SOA. We present a novel method based on genetic algorithm to design QD-SOA. Since it is essential to having a model for designing, a numerical model is obtained in the first step. Then, an artificial neural network model is made using training data sampled from numerical model. The experiments show the proposed neural model has high accuracy as well as low computation time. In the next step, we convert the design problem to a genetic algorithm problem. Using neural model, the suitable fitness function is defined. The user can optimize the cost of production by setting the weight for the design parameters. The proposed system finds the best solution that satisfies desired gain regarding the production cost.