Active and passive microring resonator filter applications in GaInAsP/InP

Single and double microring resonator filters are demonstrated with radii of 100 /spl mu/m and 200 /spl mu/m. The resonators have the shape of a racetrack. Multimode interference (MMI) couplers and codirectional couplers are used for coupling. The single ring resonator contains two codirectional couplers and includes an integrated gain section, which controls the energy flow in the ring. The passive double ring resonator contains two MMI couplers for I/O coupling acid a codirectional coupler in between the rings. A free spectral range of 50 GHz and 100 GHz has been realized.