{'fraction_non_alphanumeric': 0.019448946515397084, 'fraction_numerical': 0.012965964343598054, 'mean_word_length': 5.574468085106383, '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}}
Semiconductor optical amplifier based multi-wavelength lasers in 0.4 nm channel spacing

We propose a multi-wavelength fiber laser employing a double-pass Mach–Zehnder interferometer filter, a piece of polarization maintaining fiber, a semiconductor optical amplifier and an optical isolator. The proposed fiber laser has the advantages of stable multi-wavelength lasing with 33 channels in standard wavelength division multiplexing channel spacing of 0.4 nm using 15 m polarization maintaining fiber. Power ripple among channels could be reduced by increasing the bias current of the semiconductor optical amplifier.