Plasmonic hollow-core photonic band gap fiber for efficient sensing of biofluids

We report a new family of hollow-core photonic crystal fibers with embedded metal wires for sensitive refractive index measurement of fluids. These fibers operate on the principle of resonant coupling of the guided core mode with the surface plasmon mode generated at the surface of metal wires embedded in the photonic crystal structure. A maximum sensitivity of 2151 nm RIU−1 (nanometer per refractive index unit) can be achieved even for refractive index values lower than 1.26. The fiber is simple in design and can be fabricated with a certain modification to the conventional hollow-core photonic band gap fiber manufacturing technique. The proposed design is useful for detecting a small change in refractive index of the sample and may be implemented to estimate the bulk permittivity of the core fluid.