title: Femtosecond laser written optofluidic sensor: Bragg Grating Waveguide evanescent probing of microfluidic channel.
abstract: Microfluidic channels and Bragg Grating Waveguides (BGWs) were simultaneously fabricated inside fused silica glass by means of femtosecond laser exposure followed by chemical etching. Evanescent field penetration of the waveguide mode into the parallel microfluidic channel induced Bragg resonant wavelength shifts to enable refractive index characterization of the fluidic medium in the 1 to 1.452 range. Laser exposure was optimized to fabricate devices with optically smooth channel walls and narrow Bragg resonances for high sensing response at 1560 nm wavelength. Reference gratings were also employed in the optical circuit for temperature and strain compensation. These devices open new directions for optical sensing in three-dimensional optofluidic and reactor microsystems.
authors: The Edward S Rogers Sr Department of Electrical and Computer Engineering, Institute for Optical Sciences, University of Toronto, M5S 3G4 Toronto, Ontario, Canada. valeria.maselli@utoronto.ca
authors: Valeria
authors: V
authors: Maselli
authors: Jason R
authors: JR
authors: Grenier
authors: Stephen
authors: S
authors: Ho
authors: Peter R
authors: PR
authors: Herman
mesh_terms: D004867:Equipment Design; D007834:Lasers; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D044085:Microfluidics / Q000295:instrumentation*; D016011:Normal Distribution; D055095:Optics and Photonics; D012031:Refractometry / Q000295:instrumentation; D015203:Reproducibility of Results; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014159:Transducers
chemical_list: D012822:Silicon Dioxide