Temperature-independent silicon subwavelength grating waveguides

We demonstrate, by experiment and numerical calculations, temperature-independent subwavelength grating waveguides with a periodic composite core composed of alternating regions of silicon and SU-8 polymer. The polymer has a negative thermo-optic (TO) material coefficient that cancels the large positive TO effect of the silicon. Measurements and Bloch mode calculations were carried out over a range of silicon\u2013polymer duty ratios. The lowest measured TO coefficient at a wavelength of 1550nm is 1.8 7 10 126 K 121; 2 orders of magnitude smaller than a conventional silicon photonic wire waveguide. Calculations predict the possibility of complete cancellation of the silicon waveguide temperature dependence.Peer reviewed: YesNRC publication: Ye