Flying Particle Microlaser and Temperature Sensor in Hollow-Core Photonic Crystal Fiber

TL;DR

This paper introduces a flying whispering-gallery mode microlaser within a hollow-core photonic crystal fiber, enabling long-distance propulsion, high-resolution temperature sensing, and precise light delivery.

Contribution

It demonstrates a novel flying WGM microlaser system in HC-PCF that can be propelled over centimeters and used for temperature sensing and remote light delivery.

Findings

Microparticle can be propelled over multi-centimeter distances within HC-PCF.

Lasing wavelength shifts with temperature, enabling high-resolution sensing.

System allows precise light delivery to remote locations.

Abstract

Whispering-gallery mode (WGM) resonators combine small optical mode volumes with narrow resonance linewidths, making them exciting platforms for a variety of applications. Here we report a flying WGM microlaser, realized by optically trapping a dye-doped microparticle within a liquid-filled hollow-core photonic crystal fiber (HC-PCF) using a CW laser and then pumping it with a pulsed excitation laser whose wavelength matches the absorption band of the dye. The laser emits into core-guided modes that can be detected at the endfaces of the HC-PCF. Using radiation forces, the microlaser can be freely propelled along the HC-PCF over multi-cm distances - orders of magnitude further than in previous experiments where tweezers and fiber traps were used. The system can be used to measure temperature with high spatial resolution, by exploiting the temperature-dependent frequency shift of the lasing modes, and also for precise delivery of light to remote locations.