{'fraction_non_alphanumeric': 0.0107095046854083, 'fraction_numerical': 0.0, 'mean_word_length': 5.504347826086956, '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}}
Terahertz sources based on the intracavity wave mixing of self-generated fields in semiconductor lasers

A concept of intracavity nonlinear wave mixing using modes generated in semiconductor injection lasers as an intracavity optical pump for the mixing is developed. This approach utilizes very high nonlinear susceptibilities of III-v semiconductors that cannot be used as a passive externally pumped crystal because of the strong absorption of the optical pump and the absence of a convenient phase-matching scheme. In particular, it opens prospects for mastering the terahertz frequency range on the basis of a standard heterolaser technology. We review recent theoretical and experimental investigations in the field and discuss applications.