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Modulation Instability Based Fiber Devices for Ultrafast All-Optical Switching

Mohammed N. Islam and Carl E. Soccolich

For the ultrafast applications, fibers themselves are an attractive medium in which to do the switching. For a fused silica fiber, the response time of the nonlinearity is about 6 femtoseconds (10-15sec). A figure of merit for nonlinear optical devices is n2/α, where n2 is the nonlinear index coefficient and a is the absorption coefficient. In fibers, this ratio is favorable because of the small value of α. Also, because of the excellent guiding properties of fibers and the low loss near 1.5 μm, long length of fibers can be used, thereby reducing the power requirements. Although long length of fibers introduces a latency (delay between the inputs and outputs), the fast response times permit use of a pipelined architecture. Furthermore, there exists a mature fiber technology that can be exploited if devices are made out of fibers.