title: Athermal silicon nitride ring resonator by photobleaching of Disperse Red 1-doped poly(methyl methacrylate) polymer.
abstract: To fabricate athermal silicon nitride waveguides, the dimensions of both the core and cladding, refractive index, and thermo-optic coefficients must be controlled precisely. We present a simple and effective method for the postfabrication trimming of silicon nitride ring resonators that overcomes the highly demanding fabrication. In order to manipulate the polymer's refractive index and thermo-optic coefficient, we bleached the Disperse Red 1-doped poly(methyl methacrylate) (DR1/PMMA) top cladding using UV irradiation. After a suitable bleaching time, the temperature-dependent wavelength shift of the ring resonator was reduced from -9.8 to -0.018 pm/°C, which is the lowest shift that we are aware of for an athermal waveguide realized by overlaying a polymer cladding to date.
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga, Fukuoka 810-8580, Japan.
authors.forename: Feng
authors.initials: F
authors.lastname: Qiu
authors.forename: Feng
authors.initials: F
authors.lastname: Yu
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Spring
authors.forename: Shiyoshi
authors.initials: S
authors.lastname: Yokoyama