Fabrication and characterization of solid-core photonic crystal fiber with steering-wheel air-cladding for strong evanescent field overlap

We report the fabrication and characterization of a photonic crystal fiber with solid-core and steering-wheel pattern air-cladding (SW-PCF). Specifically, SW-PCF is fabricated using sol–gel casting technique. Attenuation spectrum shows the fiber losses of 0.14 dB/m, 0.087 dB/m, and 0.0 32 dB/m at wavelengths of 850 nm, 1000 nm, and 1500 nm, respectively, while the cut-off wavelength for single-mode operation is 1360 nm. Near-field imaging is used for the determination of mode-field diameter. The fiber presents the anomalous dispersion expending to short wavelength range with high non-linearity. Tapered SW-PCFs in the transverse geometries are numerically calculated, which suggests that the tapering of fiber holds a significant promise for the enhancement of power overlap in air holes. Properly designed and fabricated SW-PCF can thus be utilized as attractive platform for evanescent field sensing and detection.