Coherent master equation for laser modelocking

Modelocked lasers constitute the fundamental source of optically-coherent ultrashort-pulsed radiation, with huge impact in science and technology. Their modeling largely rests on the master equation (ME) approach introduced in 1975 by Hermann A. Haus. However, that description fails when the medium dynamics is fast and, ultimately, when light-matter quantum coherence is relevant. Here we set a rigorous and general ME framework, the coherent ME (CME), that overcomes both limitations. The CME predicts strong deviations from Haus ME, which we substantiate through an amplitude-modulated semiconductor laser experiment. Accounting for coherent effects, like the Risken-Nummedal-Graham-Haken multimode instability, we envisage the usefulness of the CME for describing self-modelocking and spontaneous frequency comb formation in quantum-cascade and quantum-dot lasers. Furthermore, the CME paves the way for exploiting the rich phenomenology of coherent effects in laser design, which has been hampered so far by the lack of a coherent ME formalism

Experimental observation of coherent optical oscillations in picosecond semiconductor lasers under strong-field conditions

Extremely-high-frequency (1.1 THz) coherent oscillations of the optical field emitted by a semiconductor laser were observed for the first time. The optical spectrum had a doublet structure with a 2.6 nm separation. The oscillation frequency depended on the pumping conditions and was not equal to the reciprocal of the round-trip time of the laser cavity. The power density of the laser radiation was estimated to be in the range of 109 W cm-2. © 1994 Kvantovaya Elektronika and Turpion Ltd

Ultrafast single-mode self-pulsations in multi-quantum-well ingaasp/inp diode lasers with λ/4-phase-shifted distributed feedback and a triple contact

Single-mode self-pulsations repeated at rates in excess of 28 GHz were generated for the first time by high- current injection in a 1.5 μm multi-quantum-well diode laser with phase-shifted distributed feedback and a triple contact. The build-up of the pulsations was observed. The effect was attributed to dispersive self-Q-switching in distributed- feedback lasers. © 1995 Kvantovaya Elektronika and Turpion Ltd