{'fraction_non_alphanumeric': 0.027745664739884393, 'fraction_numerical': 0.0, 'mean_word_length': 5.013888888888889, '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}}
Automatic Generation of Noise-Like or Mode-Locked Pulses in an Ytterbium-Doped Fiber Laser by Using Two-Photon-Induced Current for Feedback

We present a simple, reliable, and fast method to automatically generate noise-like or mode-locked pulses in a fiber laser. To generate the targeted pulses, we employed two-photon-induced current from a photocell as the feedback signal to control a set of rotatable wave plates in the laser. The effectiveness of using the two-photon absorption signal to discriminate noise-like pulses from mode-locked pulses is theoretically analyzed and experimentally confirmed. We demonstrate our method by using a dispersion-mapped ytterbium-doped fiber ring laser with nonlinear polarization evolution that can generate either noise-like or mode-locked pulses. The average time to attain the prescribed pulses is within a few minutes.