{'fraction_non_alphanumeric': 0.01809954751131222, 'fraction_numerical': 0.0, 'mean_word_length': 4.753246753246753, '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}}
Self-calibrating technique for beam divergence measurements of cw and pulsed lasers.

A convenient method to measure beam divergence of laser beams is described. The apparatus is compact and accurate due to the use of a telescope to focus the beam. Incorporation of a Fabry-Perot etalon permits focusing and in situ calibration. Measurement of single-pulse beam divergence is performed with a CCTV system which includes a video tape recorder.