Design and performance of superconducting circuits for LiNbO/sub 3/ optical modulator and switch

The design and performance of a LiNbO/sub 3/ optical modulator and switch, which employ superconducting circuits, have been studied. Based on a novel design method of the booster circuit using superconducting coplanar waveguide transmission lines, we designed a voltage amplifier with center frequency of 10 GHz, bandwidth of 5 MHz, and the voltage gain of 33 dB using an electromagnetic wave simulator. We also designed a high speed optical switch combining optical directional coupler and Mach-Zehnder interferometer. A preliminary experiment with YBCO electrode on MgO substrate flip-chip-bonded on LiNbO/sub 3/ optical waveguide has been made.