Very short integrated-optic Fabry-Perot cavity-coupler switch forDC and high bandwidth operation

A novel integrated-optic coupling configuration if proposed. The device operation is based on the confinement of the coupling zone to the length of a very short Fabry-Perot cavity. The cavity is electrooptically coupled with a parallel outcoupling guide. By employing accurate lithographic techniques for the fabrication of milled integrated mirrors, with total lengths of the order of 5-10 μm, devices 100 to 200 μm long can be considered. These can perform full coupling operation at bandwidths in the range of many tens of gigahertz with typically a 12-15-dB extinction ratio. The same configuration can also be used for low-frequency switching, where an extinction ratio of >20 dB is expected. Calculated results are based on the parameters of Ti:LiNbO₃ waveguides supporting 1.53-μm wavelength TM mode