MMI-coupled ring resonators in GaInAsP-InP

The characteristic response of single and double GaInAsP-InP ring resonators in the form of race tracks with a radius of 100 and 200 μm are presented. The used multimode interference (MMI) coupler is as short as 150 μm. A contrast of 13 dB, a finesse of six, and free spectral ranges of 50 and 100 GHz have been achieved for the single ring resonator. The double ring resonator has a full-width at half-maximum (FWHM) of 0.25 nm for the throughput port and 0.4 nm for the drop port.