Athermal Chalcogenide Microresonator Cladded With Polymer

We proposed and demonstrated an athermal microring resonator in high index-contrast chalcogenide glass film GeSbSe with SU-8 cladding. Due to the negative thermo-optic coefficient of SU-8, we experimentally achieved near athermal behavior with a minimum thermally induced resonance shift of 2 pm/°C at around 1550 nm, over twenty times less than that of a regular chalcogenide waveguide. We also demonstrated that the device has a low-temperature sensitivity of <10 pm/°C over an optical bandwidth of ∼100 nm. Moreover, the power-dependent transmission spectra of the resonator show that polymer SU-8 can improve thermal stability of the device at high input power, thus highly appealing for nonlinear applications.