Ultrafast, low power, and highly stable all-optical switching in an all polarization maintaining fiber Sagnac interferometer

An ultrafast, low-power, and highly stable all-optical switch in a nonlinear Sagnac interferometer is reported. To achieve low-power, highly stable, and walkoff free switching, use is made of a small-core dispersion-shifted polarization-maintaining fiber loop (200 m in length) which has a small group delay difference between the wavelengths of the input signal and the control pulse. To achieve complete polarization stability, a wavelength-sensitive polarization-maintaining fiber coupler is employed. Highly stable and walkoff free all-optical switching is demonstrated at 5 Gb/s.>