Optically excited microwave ring resonators in gallium arsenide

Microstrip ring resonators with fundamental frequencies near 3.5 GHz have been fabricated in semi‐insulating GaAs using an electroplating technique for conductor deposition. Test signals were coupled into the resonators by focusing modulated light into a photoconductive microstripline gap. Loaded Q‐factors measured for one of the rings with optical excitation ranged from 54 at the fundamental frequency to 103 at the third harmonic.