Monolithic optofluidic ring resonator lasers created by femtosecond laser nanofabrication

Abstract

We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ/mm2. Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3×104, which is limited by both solvent absorption and scattering loss. In particular, a Q-factor resulting from the scattering loss can be as high as 4.2×104, suggesting the feasibility of using a femtosecond laser to create high quality optical cavities.

Biological Lasers for Biomedical Applications

“…The whispering gallery mode (WGM) laser cavities can be constructed in the form of solid cylinders, circular‐shaped capillaries, microspheres, microdroplets, microdisks, ring‐shaped waveguides, and rectangular shaped rods . The WGM cavity relies on the total internal reflection at the curved boundary to provide optical feedback.…”

Sensing and lasing applications of whispering gallery mode microresonators

“…Since Garrett et al demonstrated the first WGM lasers in 1961 2 , WGM microresonators have been widely used in the field of microlasers because of the high Q factor and the small mode volumes 8,25,53,[61][62][63][64] . Due to these advantages, microlasers based on WGM microresonators can obtain an ultralow lasing threshold.…”

Optofluidic Microlasers based on Femtosecond Micromachining Technology

“…In 2015 the design, fabrication, and characterization of a monolithically integrated optofluidic ring resonator using FMT has been reported [16].…”

“…In the next section we will briefly review: the first demonstration of an optofluidic resonator realized by FMT given more than a decade ago [15] and a recently reported optofluidic ring resonator fabricated by femtosecond laser nanofabrication in two glass substrates melted together as post-process [16]. In the third section we will summarize our recent results by coupling FMT with high resolution ink-jet printing to realize low threshold Fabry-Perot resonators in monolithic microfluidic platforms…”