Shuna Li

The un-symmetric hybridization of graphene surface plasmons incorporating graphene sheets and nano-ribbons

Un-symmetric hybridization of graphene surface plasmons (GSPs) in waveguides incorporating graphene nano-ribbons and an underlying graphene sheet is theoretically studied. By tuning the chemical potential of the sheet, the characteristics of the hybrid modes can be shifted from sheet-like toward ribbon-like. The performance of hybrid modes reaches the maximum when phase match is satisfied. Superior to symmetric ribbon pairs, the favorable hybrid modes can be tuned at their best states, while the other modes are suppressed. The hybrid waveguide GSPs mode supported by this structure could extend the propagation distance by 46% over that of the modes for ribbon pairs.

Highly Sensitive, Bloch Surface Wave D-Type Fiber Sensor

A novel sensor based on a D-type optical fiber coated with a specially designed dielectric multilayer forming a one-dimensional photonic bandgap structure is proposed. The characteristics of its propagation modes are numerically analyzed at a wavelength of 785 nm to evaluate the sensors performance. The results show that its sensitivity can drastically exceed that of its metal-coated, surface plasmon resonance counterpart, due to the sharp resonance and low wave-propagation loss of its Bloch surface wave. The novel sensor can also be easily adapted for all kinds of aqueous analytes of different refractive indices by modifying the photonic bandgap structure. This could lead to the development of compact, ultra-sensitive biochemical sensing devices.

Fluidic sensor based on the side-opened and suspended dual-core fiber

For accelerating the response and enhancing the sensitivity simultaneously, a novel fluidic sensor based on a side-opened and suspended dual-core fiber and dual-beam interference detection mechanism is first explored and analyzed here. The side opening ensures a fast response by allowing fluidic analyte to approach the fiber core laterally. The dual-beam Mach-Zehnder interferemetry provides a relative higher sensitivity. Calculation results show that a sensitivity of 2.1×10(-6) refractive index unit (RIU) within a response time of 10 s could be achievable, which reflects its potential impact on constructing a fluid refractometer for fast-response and high-sensitivity detection. Moreover, the relationship of the sensing sensitivity and the detected dynamic range of this suspended dual-core fiber structure, polarization, and the transmitting waveband are also analyzed.

Characteristic Optimization of Multilayer Dielectric for the Bloch-Surface-Wave Based Sensor

Through numerical simulations, some rules among the BSW characteristic information can be obtained. This paper points out that the narrowest reflectance dip, the maximum GH shift, the maximum penetration depth are obtained when the resonant angles close to the critical angle. And at that position the sensitivity is higher.

Boosting Goos-Hanchen shift from a Bloch surface wave structure by optimizing excitation angles

The Goos-Hanchen shift is studied via varying the theoretical model of photonic crystal structure. The giant GH shift is obtained when resonant angle near the critical angle, and enhanced about an order of magnitude.