Optical Gain in Solids after Ultrafast Strong-Field Excitation

Qasim, Muhammad; Zimin, Dmitry A. and Yakovlev, Vladislav S. (2021): Optical Gain in Solids after Ultrafast Strong-Field Excitation. In: Physical Review Letters, Vol. 127, No. 8, 87401

Abstract

Multiphoton excitation of a solid by a few-cycle, intense laser pulse forms a very nonequilibrium distribution of charge carriers, where occupation probabilities do not necessarily decrease with energy. Within a fraction of the pulse, significant population inversion can emerge between pairs of valence-band states with a dipole-allowed transition between them. This population inversion leads to stimulated emission in a laser-excited solid at frequencies where the unperturbed solid is transparent. We establish the optimal conditions for observing this kind of strong-field-induced optical gain.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 0031-9007
• Language: English