Dynamic Thermal Effect in a Hollow Core Microbottle Resonator

Dynamic thermal wavelength shift in hollow core microbottle resonators has been experimentally demonstrated using the frequency-detuning method. A linewidth broadening phenomenon is observed when the tunable laser is swept from a shorter wavelength to a longer wavelength. The thermal effect in the microbottles with various diameters as a function of the power and sweep frequency of the tunable laser has been studied and analyzed. In addition, the effect of thermal broadening on multiple WGM resonances within the spectrum has been observed, demonstrating that broadening of the linewidth of the first WGM resonance suppresses the subsequent WGM resonances during the up-scanning cycle of the tunable laser. Study of the dynamic response of the microbottle is beneficial for the design of ultrahigh-resolution optical fiber thermometers and low threshold mode-locked lasers.