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arXiv 2001.080812020-01-22physics.opticsphysics.atom-ph

Rotational Quantum Beat Lasing Without Inversion

Maria Richter, Marianna Lytova, Felipe Morales, Stefan Haessler, Olga Smirnova, Michael Spanner, Misha Ivanov

发表信息：: Optica 7(6) (2020) 586-592
DOI：: 10.1364/OPTICA.390665

英文摘要：

In standard lasers, light amplification requires population inversion between an upper and a lower state to break the reciprocity between absorption and stimulated emission. However, in a medium prepared in a specific superposition state, quantum interference may fully suppress absorption while leaving stimulated emission intact, opening the possibility of lasing without inversion. Here we show that lasing without inversion arises naturally during propagation of intense femtosecond laser pulses in air. It is triggered by the combination of molecular ionization and molecular alignment, both unavoidable in intense light fields. The effect could enable inversionless amplification of broadband radiation in many molecular gases, opening unusual opportunities for remote sensing.

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