{'fraction_non_alphanumeric': 0.03344867358708189, 'fraction_numerical': 0.016147635524798153, 'mean_word_length': 4.7105263157894735, '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}}
Single longitudinal mode laser generation using coupled microfiber Mach–Zehnder interferometer filter

The fabrication and operation of a single longitudinal mode (SLM) laser using a compact coupled microfiber Mach–Zehnder interferometer (CM-MZI) in an erbium doped fiber (EDF) laser cavity is demonstrated. The CM-MZI is created by first fabricating an optical microfiber using the flame-brushing technique before being cut and rejoined to form a half-loop, which is the basis for the CM-MZI structure. The CM-MZI is inserted into an EDF laser cavity; the filtering effect of the CM-MZI induces a stable SLM lasing output with a consistent 3 dB bandwidth of 0.02 nm at different a pumping power and signal-to-noise ratio of ~50 dB. The output also exhibits minimal wavelength and power fluctuations of 0.02 nm and 0.15 dB, respectively, over a time period of 60 min.