Wavelength Conversion And Optical Logic Xor Gate Based On Linear Optical Amplifier

Through the build of vertical microcavity laser (VCL) in active medium, linear optical amplifier (LOA) clamps gain and suppresses crosstalk. Characterizing with remarkable linear gain, LOA is widely used in WDM system. Furthermore, it is also a promising candidate as a nonlinear device in all-optical signal processing, such as wavelength conversion, logic gate, wavelength router, high-speed optical switching, to overcome the limitations of electronic bottleneck and achieve high capacity and rate information processing.Using some theories and methods of semiconductor optical amplifier (SOA), vertical cavity semiconductor optical amplifier (VCSOA) and vertical cavity surface emitting laser (VCSEL), the multi-section model of LOA was built based on rate equations. Utilizing the advantages of parallel processing and modularization of Simulink, a dynamic visual model of LOA has been developed for the first time. The model took into account the reflection at input and output face, amplified spontaneous emission noise and gain clamping by VCL. It can simulate the static and dynamic characteristics of LOA effectively. Based on the model, the gain clamping characteristics were analyzed; in order to analyze the nonlinear application, the model was extended to wavelength conversion and optical logic XOR gate models based on Mach-Zehnder interferometer (MZI) by addressing two LOAs in two arms of MZI. Several theoretical studies have been carried out as following:(1). Analyzing the carrier density and photon density of VCL in active region, the physical mechanism of gain clamping was revealed. The dynamic characteristics, including crosstalk, relaxation oscillation and gain saturation behaviors, were studied by constructing a system with two forward-propagating signal channels. (2). Wavelength conversion was simulated at data rate of 10 Gb/s. The performances of output signals were theoretically analyzed with variations of signal beam, probe beam and signal rate in the different reflectivity of distributed Bragg reflector (DBR) mirrors.(3). Utilizing a differential phase scheme, the limitations of signal processing rate imposed by carrier recovery time were solved. All-optical logic XOR operation was demonstrated at data rate of 40 Gb/s. The optimization of system parameters was favorable to enhance the logic XOR operation performance. The advantages...