High precision integrated photonic thermometry enabled by a transfer printed diamond resonator on GaN waveguide chip

We demonstrate a dual-material integrated photonic thermometer, fabricated by high accuracy micro-transfer printing. A freestanding diamond micro-disk resonator is printed in close proximity to a gallium nitride on a sapphire racetrack resonator, and respective loaded Q factors of 9.1 × 10 4 and 2.9 × 10 4 are measured. We show that by using two independent wide-bandgap materials, tracking the thermally induced shifts in multiple resonances, and...