Phase-Shifted Bragg Gratings from High Refractive Index Chalcogenide Hybrid Inorganic/Polymers: Fabrication and Thermo-Optic Characterization

In this study, the first fabrication of phase-shifted Bragg gratings utilizing chalcogenide hybrid inorganic/organic polymers (CHIPs) is presented based on poly(sulfur-random-(1,3-isopropenylbenzene) to measure the thermo-optic coefficient (TOC) of this new class of optical polymers. The unique properties of CHIPs, such as high index contrast and low optical losses, are leveraged to fabricate Bragg gratings that enable precise determination of the TOC and glass transition temperature (T_g) of these polymers. The optical measurement introduces a novel technique to measure the TOC and T_g of optical polymers which can be difficult to determine using traditional methods such as differential scanning calorimetry (DSC) after fabrication into photonic device constructs. The findings demonstrate that CHIPs exhibit low thermo-optic (TO) effects, making them exceptionally well-suited for the development of thermally stable photonic integrated circuits.