Integrated optical racetrack resonator fabricated by silver ion exchange in glass

The frequency selectivity of integrated optical ring resonators makes them key components for many devices, including filters, switches and sensors. The ion-exchange technique is an economical and simple method to fabricate good quality optical waveguides and useful devices. In this paper, with the mixed melt salt of AgNO3 and KNO3 used as the source of exchanging ions, a racetrack waveguide resonator was fabricated in K9 glass. The reflection and transmission spectra of the resonator were measured, and the coupling ratio and propagation loss were derived by an improved method. The phase shift of 2π was realized by using thermo-optical effect within 16 degree change of temperature. The resonator is a promising device for filtering, sensing and other applications.