{'fraction_non_alphanumeric': 0.00980392156862745, 'fraction_numerical': 0.0, 'mean_word_length': 6.222222222222222, '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}}
Detection of Ultrasonic Longitudinal and Shear Waves Using Optical Heterodyne Interferometer

An optical heterodyne interferometer was developed to enable noncontact detection of ultrasonic motions parallel and perpendicular to the specimen surface. Two optical setups, one for the parallel direction and another for the perpendicular direction, were included in the interferometer. The interferometer enabled simultaneous ultrasonic detection in both directions at the same point on the specimen surface without changing the optical layout of the interferometer. For verification of the technique, longitudinal and shear ultrasonic waves generated by piezoelectric transducers were detected by the interferometer.