OPTICAL INTERSECTING WAVE-GUIDE SWITCHES WITH CURVED ELECTRODES

Reflection type optical switches with intersecting waveguides and curv ed electrodes are newly proposed. The guided incident mode is expanded into an infinite spectrum of plane wavelets. The effects of light tun neling into the transmission port is taken care of by treating the 3-l ayer structure and using its reflection and transmission coefficients in estimation of the extinction ratios. It is found that the electrode curved in the form of an exponential spiral provides remarkably impro ved power reflectivity. This is because it poses a constant angle of i ncidence (smaller than the critical angle) to all variously oriented i mpinging wavelets. In this way, all plane wavelets are made to underta ke total reflections. These total reflections result in considerably h igh extinction ratios to be achievable at the transmission port. It is also shown that the electrode length is shorter and the intersection angle is wider than those corresponding to a straight electrode. There fore, it is concluded that the curvature of the electrode improves the switching characteristics of the device.