{'fraction_non_alphanumeric': 0.02155688622754491, 'fraction_numerical': 0.008383233532934131, 'mean_word_length': 4.76551724137931, '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}}
Low Cost Vibrometer Utilizing Laser Diode Self-Mixing with Sound Card Controlled by LabVIEW

A compact and versatile vibrometer is designed based on self-mixing laser diode vibrometry interference to measure the oscillation amplitude of a piezoceramics (PZT). A fraction of the light emitted by the laser diode (LD) is reflected by the PZT, and then mixes with the light inside the cavity, causing a modulation of the laser output. The self-mixing signal is detected by the photodiode accommodated in the LD package and acquired by a data acquisition and processing system based on sound card and LabVIEW. Amplitude of the PZT is detected by fringe counting. According to results of test, this device can measure the vibration signal with a measurement accuracy of λ/2. The measurable oscillation amplitude range from 0.325 um to 6.5um