title: High-Q width modulated photonic crystal stack mode-gap cavity and its application to refractive index sensing.
abstract: An optical sensor based on One-Dimensional photonic crystal (1D PhC) stack mode-gap cavity has been designed, fabricated and characterized. By introducing quadratically modulated width tapering structure, a waveguide coupled 1D PhC stack mode-gap cavity with calculated Q-factor 1.74 × 10(7) and an effective mode volume 1.48(λ/n(Si))(3) has been designed. This cavity has been used for sensing applications by immersing into water-ethanol mixture of different volume concentrations. Transmission measurement shows a quality factor as high as 27, 000 can be achieved for the cavity immersed in analytes. A sensitivity of 269nm/RIU has been demonstrated.
authors.affiliation: Centre for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang Provincial Key Laboratory for Sensing Technologies, Zhejiang University, Zijingang Campus, Hangzhou, China.
authors.forename: Kaiyuan
authors.initials: K
authors.lastname: Yao
authors.forename: Yaocheng
authors.initials: Y
authors.lastname: Shi
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D017076:Computer-Aided Design; D003460:Crystallization / Q000379:methods; D004867:Equipment Design; D006801:Humans; D049329:Nanostructures / Q000737:chemistry*; D055096:Optical Devices; D014159:Transducers