{'fraction_non_alphanumeric': 0.013182674199623353, 'fraction_numerical': 0.0, 'mean_word_length': 5.734177215189874, '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}}
Interferometric determination of refractive indices and birefringence of fibres with irregular transverse sections

An interferometric method is described for the determination of the mean refractive indices and birefringence of fibres with irregular transverse sections. Multiple-beam Fizeau fringes are made to cross the fibre perpendicular to its axis. To eliminate the need for measurements of the transverse sectional area of the fibre, two immersion liquids, of different refractive indices, are used at the same temperature.