Nonlinear phase shift at 1.55 /spl mu/m in CW single-pass waveguided cascaded parametric interactions

Summary form only given. In the search for high speed, low-power, all optical switching devices, the generation of phase shifts through quadratic cascading has emerged as one of the most promising techniques. However, practically all the experiments to date have been based on pulsed second harmonic generation configurations, which does not satisfy the essential demands of a general switching protocol: treatment of low power signals and possibility of signal power independent packet switching, as well as CW or quasi-CW operation. Hutchings et al. have proposed a slightly different scheme based on two non-degenerate difference-frequency generation (DFG) processes where an injected pump beam is used to control the phase of the signal beam of interest, which allows processing very weak signals.