title: Plasmonic external cavity laser refractometric sensor.
abstract: Combining the high sensitivity properties of surface plasmon resonance refractive index sensing with a tunable external cavity laser, we demonstrate a plasmonic external cavity laser (ECL) for high resolution refractometric sensing. The plasmonic ECL utilizes a plasmonic crystal with extraordinary optical transmission (EOT) as the wavelength-selective element, and achieves single mode lasing at the transmission peak of the EOT resonance. The plasmonic ECL refractometric sensor maintains the high sensitivity of a plasmonic crystal sensor, while simultaneously providing a narrow spectral linewidth through lasing emission, resulting in a record high figure of merit for refractometric sensing with an active or passive optical resonator. We demonstrate single-mode and continuous-wave operation of the electrically-pumped laser system, and show the ability to measure refractive index changes with a 3σ detection limit of 1.79 × 10(-6) RIU. The demonstrated approach is a promising path towards label-free optical biosensing with enhanced signal-to-noise ratios for challenging applications in small molecule drug discovery and pathogen sensing.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.forename: Meng
authors.initials: M
authors.lastname: Lu
authors.forename: Chun
authors.initials: C
authors.lastname: Ge
authors.forename: Brian T
authors.initials: BT
authors.lastname: Cunningham
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D007368:Interferometry / Q000295:instrumentation*; D007834:Lasers; D036103:Nanotechnology / Q000295:instrumentation; D012031:Refractometry / Q000295:instrumentation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*