Tunable single mode lasing from an on-chip optofluidic ring resonator laser

Single mode lasing from the polydimethylsiloxane based on-chip coupled optofluidic ring resonator (OFRR) with the lasing threshold of a few μJ/mm2 is demonstrated using the Vernier effect. The single mode operation is highly stable even at high pump energy densities. The effect of the OFRR size and coupling strength on the single mode emission is investigated, showing that the excessive coupling results in incomplete side mode suppression. Tuning of the lasing wavelength is achieved by modifying the dye solution.