Polarization-independent tilted fiber Bragg grating surface plasmon resonance sensor based on spectrum optimization.

We experimentally demonstrated polarization multiplexing schemes in a tilted fiber grating (TFBG) to achieve polarization-independent fiber-optic surface plasmon resonance (SPR) sensors. The first used two orthogonal polarized lights separated by a polarization beam splitter (PBS) that are p-polarized in polarization-maintaining fiber (PMF) and precisely aligned with the tilted grating plane, so as to achieve the transmission of p-polarized light in two opposite directions of the Au-coated TFBG to excite SPR. Alternatively, polarization multiplexing was also achieved by exploring two polarization components to achieve the SPR effect through a Faraday rotator mirror (FRM).

Polarization-independent microchannel in a high-speed-scan femtosecond laser-assisted etching of fused silica.

Microchannels fabricated by femtosecond laser-assisted chemical etching are of great use in biochemical analysis. In this paper, we study the morphology change of etched microchannels in fused silica by controlling the laser scan speed, and we find a significant difference between the chemical etched length and volume. The fabricated microchannels would gradually become tapered along the scan direction, which influences the flow of the hydrofluoric (HF) reagent and the etching rate.