Optical-microwave intermixing of a CPW-to-slotline ring resonator on GaAs substrate

We report the optical-microwave intermixing using an uniplanar CPW-to-slotline ring resonator fabricated on a semi-insulating GaAs substrate for the first time. In this structure, a conductive Schottky photodetector is monolithically integrated as a coupling gap between the coplanar waveguide (CPW) feed lines and the slotline ring resonator. Difference frequency mixing spectrum between an optically modulated RF input and a microwave LO has been demonstrated using optical excitation. The intermediate frequency (IF) response has been investigated as functions of the RF power, the LO pumping power, and the applied bias voltage. Conversion loss (in dB) has been measured as a function of LO frequency and compared to other data.