Principal Investigator Jurgen Michel
Co-investigator Lionel Kimerling
Temperature stability is a signifi cant and outstanding issue in electronicphotonic integrated devices. The uneven heat distributions from the electronic components cause unwanted temperature dependent wavelength shifts and phase shifts in the optical devices. An athermal design is especially critical in applications of wavelength (de)multiplexing and high-resolution spectroscopy because thermal fl uctuations could severely limit the wavelength resolution and aff ect the spectral channel density. This implies that all interferometric confi guration such as Mach-Zehnder interferometer, ring resonators and arrayed-waveguide gratings, require temperature control. We have developed a general approach to design temperature-independent high-index-contrast (HIC) waveguides by choosing a cladding material whose thermo-optic (TO) coeffi cient is opposite than that of the waveguide core. We present a systematic study of thermal compensation for both symmetric and asymmetric channel waveguides and derive analytical expressions for the athermal conditions. Our study shows that athermal HIC waveguides such as SOI and SiN-based systems can be practically realized by applying commercially-available polymer claddings.