{'fraction_non_alphanumeric': 0.026747195858498704, 'fraction_numerical': 0.014667817083692839, 'mean_word_length': 5.304347826086956, '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}}
Tunable multi-wavelength active conversion of 1550 nm signals in a Cr3+:LiCAF — PPSLT laser

This paper demonstrates an intra-cavity tunable and multiple wavelength conversion for optical communications in the third spectral window based on single-pass difference frequency generation (DFG) with intracavity PPSLT crystals. The experimental setup is based on single-pass difference frequency generation with a PPSLT crystal placed inside the V-folded cavity of a tunable self-injection-locked diode-pumped Cr3+:LiCAF, which oscillates around 792±8 nm with a spectral width lower than 1 nm. Thus, the spectral allocation of the converted spectrum can be tuned through the coupled cavity based on a diffraction grating (Littrow mounting) thanks to the spectral characteristics of the Cr3+:LiCAF. Despite the very limited experimental conditions available to us with the laser operating only 1.5 times above threshold with a modest intra-cavity power, it is shown that improving the laser design to approach the high conversion efficiency, even in excess of 100% if the laser is carefully designed so that conditions to achieve parametric net gain are fulfilled.