Fp-soa All-optical Information Processing Applied Research

Optical packet switching (OPS) technology will conquer the electronic bottleneck in the O/E/O (optical/electrolic/optical) switching nodes and provide the smaller switching granularity than wavelength switching. But there still exists many problems handicapping the realization of OPS. One is the"routing loop",the other is optical power variation. Routing loop is caused by the misdirected or mislabeled packets which route in circles, never reach their destination, and lead to severe network congestion. Optical packet power variation is caused by optical packets routed individually according to MPLS and experienced the different loss in the diverse transmission paths. After studied deeply in these two aspects, we proposed new schemes to realize the function of TTL and Optical power equalization whitch is based on Fabry-Perot semiconductor optical amplifier (FP-SOA). The works are listed in the following:1. A numerical model of SOA (Semiconductor Optical Amplifier) is established based on Schrodinger equation and section model. The relationships between the gain of FP-SOA (Fabry-Perot SOA) and carrier density, injection current, pulse wavelense are discussed. The influence of the injection curent on the carrier recovery time is also discussed.2. A novel scheme of decrementing one TTL (Time-to-Live) pulses based on AMZI (Asymetric Mach-Zehnder Interferometer) and FP-SOA is proposed. In this scheme, the TTL value is indicated by the number of optical pulses. When the TTL pulses pass through the AMZI, M optcal pulses are changed into M-1 pulses and two residual pulses with 6dB power difference. The work point of FP-SOA is setted at the section in which the gain increased with the depletion of the carrier dencity. After the TTL pulse passthough the FP-SOA M-1 pulses are amplified and the two residual pulses are suprresed, the contrast ratio between M-1 pulse and the two residual pulses can reach higher than 10dB. The feasibility of the scheme is verified by the simulation. The influences of injection curent, pulse power, period and width on the performance of TTL decrement module are analysed.3. A novel scheme of power equalization based on FP-SOA is proposed. Due to the gain chracteristics of FP-SOA, if the work point is setted at the section in which the gain decreased with the depletion of carrier density, the higher optical power signal obtain lower gain, the lower optical power signal achieve higher gain, in this way, optical power equalization is reliased and the power value of output pulses are clamped in a certain range. The feasibility of the scheme is verified by simulation,10dB power variation can be clamped in 1dB.. The influences of injection curent, pulse power, period and width on the performance of optical power equalization are analysed.