title: Optofluidic laser array based on stable high-Q Fabry-Pérot microcavities.
abstract: We report the development of an optofluidic laser array fabricated on a chip using stable plano-concave Fabry-Pérot (FP) microcavities, which are far less susceptible to optical misalignment during device assembly than the commonly used plano-plano FP microcavities. The concave mirrors in our FP microcavities were created by first generating an array of microwells of a few micrometers in depth and a few tens of micrometers in diameter on a fused silica chip using a CO2 laser, followed by coating of distributed Bragg reflection (DBR) layers. The plano-concave FP microcavity had a Q-factor of 5.6 × 10(5) and finesse of 4 × 10(3), over 100 times higher than those for the FP microcavities in existing optofluidic lasers. 1 mM R6G dye in ethanol was used to test the plano-concave FP microcavities, showing an ultralow lasing threshold of only 90 nJ mm(-2), over 10 times lower than that in the corresponding unstable plano-plano FP microcavities formed by the same DBR coatings on the same chip. Simultaneous laser emission from the optofluidic laser array on the chip and single-mode lasing operation were also demonstrated. Our work will lead to the development of optofluidic laser-based biochemical sensors and novel on-chip photonic devices with extremely low lasing thresholds (nJ mm(-2)) and mode volumes (fL).
authors: Key Lab of Advanced Transducers and Intelligent Control System of Ministry of Education, Taiyuan University of Technology, 79 Yingze Street, Taiyuan 030024, PR China. wangwenjie@tyut.edu.cn.
authors: Wenjie
authors: W
authors: Wang
authors: Chunhua
authors: C
authors: Zhou
authors: Tingting
authors: T
authors: Zhang
authors: Jingdong
authors: J
authors: Chen
authors: Shaoding
authors: S
authors: Liu
authors: Xudong
authors: X
authors: Fan
mesh_terms: D007834:Lasers; D046228:Microarray Analysis / Q000295:instrumentation / Q000379:methods*; D012235:Rhodamines / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D012235:Rhodamines; C026188:rhodamine 6G; D012822:Silicon Dioxide