Band-rejection filter with high extinction ratio using prism-waveguide cascaded coupling system.

A band-rejection filter is proposed based on a prism-waveguide cascaded coupling system, which is composed of an equilateral trapezium prism and a deposited multilayer structure. By properly adjusting the thickness of the coupling layer and the light extinction coefficient of the guiding layer, the radiative and intrinsic dampings matching condition could be well satisfied, and then a series of reflectivity dips will appear in the reflectivity wavelength spectrum. Since the module of reflectivity is smaller than one, the extinction ratio of the rejected frequency via the cascaded coupling system is twice as high as that of the single-coupling technology.

A possible pathogenetic factor of sickle-cell disease based on fluorescent analysis via an optofluidic resonator.

Waveguide based optofluidic resonator features high precision and high sensitivity in real-time fluorescent analysis. We present a novel optofluidic resonator following the hollow-core metal-cladding waveguide structure, which is then used to record the real-time binding process of Fe and Fe with protoporphyrin IX (PpIX) in PBS solution, respectively. The central fluorescent wavelength of compound with Fe is in good accordance with that of the normal hemoglobin, whilst the peaks of the Fe compound match the hemoglobin specimen from sickle-cell disease (SCD) patients.

High-sensitivity temperature sensor using the ultrahigh order mode-enhanced Goos-Hänchen effect.

A high-sensitivity temperature sensor based on the enhanced Goos-Hänchen effect in a symmetrical metal-cladding waveguide is theoretically proposed and experimentally demonstrated. Owing to the high sensitivity of the ultrahigh-order modes, any minute variation of the refractive index and thickness in the guiding layer induced by the thermo-optic and thermal expansion effects will easily give rise to a dramatic change in the position of the reflected light. In our experiment, a series of Goos-Hänchen shifts are measured at temperatures varying from 50.