On-chip, High-sensitivity Temperature Sensors Based on Dye-doped Solid-state Polymer Microring Lasers
We developed a chip-scale temperature sensor with a high sensitivity of 228.6 pm/°C based on a rhodamine 6G (R6G)-doped SU-8 whispering-gallery mode microring laser. The optical mode was largely distributed in a polymer core layer with a 30 μm height that provided detection sensitivity, and the chemically robust fused-silica microring resonator host platform guaranteed its versatility for investigating different functional polymer materials with different refractive indices. As a proof of concept, a dye-doped hyperbranched polymer (TZ-001) microring laser-based temperature sensor was simultaneously developed on the same host wafer and characterized using a free-space optics measurement setup. Compared to TZ-001, the SU-8 polymer microring laser had a lower lasing threshold and a better photostability. The R6G-doped SU-8 polymer microring laser demonstrated greater adaptability as a high-performance temperature-sensing element. In addition to the sensitivity, the temperature resolutions for the laser-based sensors were also estimated to be 0.13 °C and 0.35 °C, respectively. The rapid and simple implementation of micrometer-sized temperature sensors that operate in the range of 31 – 43 °C enables their potential application in thermometry.
Applied Physics Letters
Wan, L., Chandrahalim, H., Chen, C., Chen, Q., Mei, T., Oki, Y., Nishimura, N., Guo, L. J., & Fan, X. (2017). On-chip, high-sensitivity temperature sensors based on dye-doped solid-state polymer microring lasers. Applied Physics Letters, 111(6), 061109. https://doi.org/10.1063/1.4986825