{'fraction_non_alphanumeric': 0.026737967914438502, 'fraction_numerical': 0.0053475935828877, 'mean_word_length': 5.534883720930233, '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}}
Ultrafast gain dynamics in InAs-InGaAs quantum-dot amplifiers

The ultrafast dynamics of gain and refractive index in an electrically pumped InAs-InGaAs quantum-dot (QD) optical amplifier are measured at room temperature using differential transmission with femtosecond time resolution. Both absorption and gain regions are investigated. While the absorption bleaching recovery occurs on a picosecond time scale, the gain compression recovers with /spl sim/100-fs time constant, making devices based on such dots promising for high-speed optical communications.