{'fraction_non_alphanumeric': 0.029850746268656716, 'fraction_numerical': 0.01951779563719862, 'mean_word_length': 5.0137931034482754, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Highly Sensitive SPR Sensors Based on Two Parallel PCFs for Low Refractive Index Detection

Based on two parallel photonic crystal fibers (PCFs) with D-shape structure, a novel surface plasmon resonance (SPR) sensor with low refractive index (RI) detection at near-infrared wavelengths is described. According to the coupled-mode theory, directional power transfer between the two fiber cores is enhanced by resonant coupling between the surface plasmon modes and fiber core-guided modes. In comparison with corresponding single D-shape PCF, a maximum spectral sensitivity up to 13 500 nm/RIU and resolution of 7.41 × 10−6 RIU for RI detection range between 1.27 and 1.32 are achieved. The proposed two parallel D-shape PCFs-SPR sensor with lower RI detection range offer large potential in the fields of pharmaceutical inspection and pharmaceutical leakage monitoring.