InGaAsP thin-film microdisk resonators fabricated by polymer wafer bonding for wavelength add-drop filters

10-μm-diameter InGaAsP thin-film microdisk resonators have been fabricated using polymer-wafer bonding with benzocylobutene. This wafer bonding process is to provide strong two-dimensional mode confinement in the waveguide and reduce the optical propagation loss. The measured resonance linewidth at wavelength 1.55 μm is about 0.22 nm with a free-spectral range of 20 nm. The narrow linewidth and large free-spectral range make these devices conducive to the applications in dense wavelength division multiplexed systems.