{'fraction_non_alphanumeric': 0.02782608695652174, 'fraction_numerical': 0.02608695652173913, 'mean_word_length': 4.433962264150943, '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}}
Frequency stabilization of a tunable erbium-doped fiber laser.

A single-frequency Er-doped fiber laser that is tunable from 1.52 to 1.58 ,microm has been constructed. The laser linewidth was determined to be less than 1.6 MHz FWHM by observing the spectrum of the beat between the fiber laser and a 1.523-microm He-Ne laser. The frequency of the fiber laser was locked to several absorption lines of acetylene near 1.53 microm. This research demonstrates the inherent stability of fiber lasers and their potential for use in a wavelength standard for optical communications.