{'fraction_non_alphanumeric': 0.03067484662576687, 'fraction_numerical': 0.029141104294478526, 'mean_word_length': 4.629310344827586, '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}}
High-stability Er-doped superfluorescent fiber source incorporating photonic bandgap fiber

A tunable photonic bandgap fiber filter was incorporated in an Er-doped superfluorescent fiber source to improve its mean wavelength thermal stability. This simple filter was able to successfully compensate the mean wavelength to less than 10 ppm from −40 °C to 70 °C. When the environmental temperature was controlled to ±0.5 °C, the SFS exhibited a long-term mean wavelength stability of ±1 ppm over 11 hours. With 60 mW pump power at 974.2 nm, an optimal Er-doped fiber length of 8m was found, and the final output power of the compensated SFS reached 8 mW.