40 Gb/s Multifunction Optical Format Conversion Module With Wavelength Multicast Capability Using Nondegenerate Four-Wave Mixing in a Semiconductor Optical Amplifier

A 40 Gb/s multifunction optical format conversion module based on nondegenerate four-wave mixing (ND-FWM) arising in a single semiconductor optical amplifier (SOA) is proposed and demonstrated. It has the ability to achieve NRZ-OOK/DPSK/DQPSK to CSRZ-OOK/DPSK/DQPSK, RZ-OOK/DPSK/DQPSK to CSRZ-OOK/DPSK/DQPSK, and CSRZ-OOK/DPSK/DQPSK to RZ-OOK/DPSK/DQPSK format conversions. A comprehensive dynamic model to investigate twelve FWM-related waves in SOA is presented. Using this model, the proposed module with multiple format conversions is numerically investigated. We find that the SOA based scheme can be used for high-speed all-optical multifunction format conversion, because one of the FWM participators also serves as an assist light to accelerate SOA gain recovery. Meanwhile three identical converted signals with different wavelengths can be obtained simultaneously for all-optical wavelength multicast application. Finally, the bit-error-rate (BER) measurements of some 10 Gb/s operations are demonstrated in order to further verify the proposed multifunction format conversion module. The power penalty is measured to be less than 1 dB at the BER level of 10^-9.