Optofluidic ring resonator dye microlasers

摘要

We report on the development of versatile, miniaturized optofluidic ring resonator (OFRR) dye lasers that can be operated regardless of the refractive index (RJ) of the liquid. The OFRR is a piece of a thin-walled fused silica capillary that integrates the photonic ring resonator with microfluidics. In an OFRR dye laser, the active lasing materials (such as dye) are passed through the capillary whereas the circular cross section forms a ring resonator and supports whispering gallery modes (WGMs) that provide optical feedback for lasing. Due to the high Q-factors (> 10~9), extremely low lasing threshold can be achieved. The operation wavelength can conveniently be changed by using different dye and fine-tuned with solvent. The laser can be out-coupled through a fiber taper in touch with the capillary, thus providing an easy guiding for the laser emission. Our experiments demonstrate lasing through direct excitation and through efficient energy transfer (ET). Theoretical analysis and experimental results for OFRR lasers are presented.