Designing of convenient PCF structure for SERS applications

We investigated that the performance of side-channel photonic crystal fiber (SC-PCF) is controlled by the subtended angle of the liquid channel to the center point of the core (channel angle). This investigation is used for designing the SC-PCF to enhance the Surface Enhanced Raman Spectroscopy (SERS) signal. The deviation of the maximum normalized field intensity from the solid core center, and the mode field diameter change with the channel angle. We used finite element method (FEM) to obtain the normalized field intensity distributions, and a Gaussian approximation with position parameter is utilized to analyze them. The normalized field intensity on core liquid interface and the evanescent field ratio are considered to measure the performance. It is found that the performance is maximized when the channel angle is 90o at 632.8nm of excitation wavelength. These results are very important for the sensing application in chemical, biomedical engineering and research fields.