{'fraction_non_alphanumeric': 0.030107526881720432, 'fraction_numerical': 0.0, 'mean_word_length': 5.697841726618705, '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}}
Cladding-Mode Resonance in Polarization-Maintaining Photonic-Crystal-Fiber-Based Sagnac Interferometer and Its Application for Fiber Sensor

A novel cladding-mode-resonance-based polarization-maintaining photonic-crystal-fiber Sagnac interferometer (PMPCF-SI) and its application for fiber sensor are demonstrated. By introducing a mode field diameter mismatch at a splicing joint of an inbuilt single-mode fiber (SMF)-PMPCF-SMF structure connected in an SI, an intermodal interference is constructed by the excited cladding modes and the polarization modes of the PMPCF. With such a PMPCF-SI, simultaneous strain and temperature measurements are demonstrated. The SI behaves as a sensor and a filter simultaneously. By measuring the wavelength variation and transmissivity difference between two almost symmetrical resonance peaks in the spectral response of the SI, simultaneous strain and temperature measurements are achieved.