SINGLE-MODE WAVE-GUIDE MICROCAVITY FOR FAST OPTICAL SWITCHING

We investigate the properties of a tunable single-mode waveguide micro cavity that is well suited for frequency modulation and switching. The cavity mode has a volume of less than one cubic half-wavelength, and the resonant frequency is tuned by refractive-index modulation. We sug gest using a photorefractive effect to drive the device, based on the photoionization of deep donor levels known as DX centers in compound s emiconductors. Picosecond on-off switching times are achievable when t wo of these cavities are placed in series. The resulting switch has th e advantages of being compact and requiring as little as 10 pJ of ener gy of operate. (C) 1996 Optical Society of America.