We theoretically predict and experimentally demonstrate inhibition of linear absorption for phase and group velocity mismatched second- and third-harmonic generation in strongly absorbing materials, GaAs, in particular, at frequencies above the absorption edge.
A 100-fs pump pulse tuned to 1300 nm generates 650 and 435 nm second- and third-harmonic pulses that propagate across a 450−μm-thick GaAs substrate without being absorbed. We attribute this to a phase-locking mechanism that causes the pump to trap the harmonics and to impress on them its dispersive properties.
Source: University of Rome La Sapienza
Authors: Marco Centini | Vito Roppo | Eugenio Fazio | Federico Pettazzi | Concita Sibilia | Joseph W. Haus | John V. Foreman | Neset Akozbek | Mark J. Bloemer | Michael Scalora