APPLIED PHYSICS LETTERS, cilt.98, sa.4, 2011 (SCI-Expanded)
We demonstrate a technique to yield a direct and sensitive measurement of the thermo-optic coefficient (TOC) for light-emitting materials in optical microdisk resonators. Using photoluminescence from erbium-doped amorphous silicon nitride (a-SiN(x):Er) as an example, we show how the TOC can be extracted from thermally induced shifts in the resonant microdisk modes. For the highest-performance a-SiN(x):Er material composition, we find a TOC at 1.54 mu m of similar to 3 X 10(-5) K(-1) in the 300-500 K range. Additionally, our work demonstrates a convenient all-optical spectroscopic technique for sensitive temperature measurements, with a resolution of similar to 30 mK in this temperature range. (c) 2011 American Institute of Physics. [doi:10.1063/1.3545845]