All-Optical Switching with a Weak Control Signal in a Nonlinear Interferometer

We propose and study all-optical probe switching using a control signal in a nonlinear interferometer configuration. In our proposed device, we can have a power- or a phase-controlled switching function with a control signal that is much weaker than the probe signal. Since the control signal and the probe have the same wavelengths and polarizations, the pulse walk-off associated with the dispersion does not take place, and thus the speed of operation is not limited by dispersion. We have experimentally demonstrated power-controlled switching with a control signal whose power is 10 times weaker than the probe power.