Demonstration of all-optical switching with orthogonally-polarized control and signal light

Seok–Hwan Jeong, Katsumi Nakatsuhara, Tetsuya Mizumoto +2 more

We demonstrate all-optical bistable switching by using orthogonally and parallelly polarized control light in a nonlinear distributed feedback GaInAsP waveguide. When the control light that is orthogonally polarized to the signal light is within its stopband, it is possible to extract the signal without using any external devices. Also, we investigate theoretically and experimentally the dependence of threshold switching power on the wavelength and polarization of control light.

Hyatt M. Gibbs

A. P. Alodjants, A. Yu. Leksin, Sergei M Arakelyan

The analysis of formation of chaotic quantum states for two (or four) orthogonally polarized modes in a tunnelly-coupled optical fiber has been carried out. A special attention is devoted both to the structure of arising polarization instabilities and to the possibility to control of such a quantum state by procedure of quantum nondemolition measurements. New effect of polarization switching is obtained and we discuss the problem of both coding of information and construction of quantum logical elements for quantum computing. The optical schemes to realize the quantum AND (NOT-AND), OR (NOT-OR) and controlled-NOT gates with quantum nondemolition filtering of the signal are proposed.

Kumar Kumar

Jiepeng Zhang, Gessler Hernandez, Yifu Zhu

We report an experimental demonstration of all-optical switching at ultralow light levels in coherently prepared Rb atoms. A signal light pulse is switched on and off by a control light pulse at different frequencies in a four-level atomic system based on multiphoton interferences. We observed a switching efficiency of 55% with the signal and control light pulses containing approximately 20 photons each, corresponding to a control energy density of approximately 10(-5) photons per atomic cross section lambda(2)/(2pi).