In-Fiber Polymer Microdisk Resonator and Its Sensing Applications of Temperature and Humidity
Peng Ji, Meng Zhu, Changrui Liao, Cong Zhao, Kaiming Yang, Cong Xiong, Jinli Han, Chi Li, Lichao Zhang, Yifan Liu, Yiping Wang
Abstract
We proposed and realized an all-in-fiber polymer microdisk whispering-gallery mode (WGM) resonator, which is composed of a nanoscale polymer waveguide in conjunction with a polymer microdisk. The resonator is manufactured by femtosecond laser-induced two-photon polymerization inside a single-mode optical fiber, and its transmission spectrum has been investigated theoretically and experimentally. The WGM resonance was excited successfully, exhibiting a high Q factor of 2.3 × 103 at a resonant wavelength of 1416.6 nm. The temperature and humidity responses of the resonator were tested as examples of possible application. Temperature sensitivity of −96 pm/°C when the temperature increased from 25 to 60 °C and humidity sensitivity of 54 pm/%RH when the relative humidity increased from 30 to 90% were obtained. The proposed in-fiber microdisk resonator is highly suitable for detection of microorganisms, bacteria, and single molecules.