Tereshchenkov E A, Andrianov E S, Zyablovsky A A, Pukhov A A, Vinogradov A P, Lisyansky A A
Moscow Institute of Physics and Technology, 9 Institutskiy Per., Moscow, Russia, 141700.
Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow, Russia, 127055.
Sci Rep. 2022 May 9;12(1):7588. doi: 10.1038/s41598-022-11588-9.
We report on unusual regimes of operation of a laser with a gain medium with a large Raman scattering cross-section, which is often inherent in new types of gain media such as colloidal and epitaxial quantum dots and perovskite materials. These media are characterized by a strong electron-phonon coupling. Using the Fröhlich Hamiltonian to describe the electron-phonon coupling in such media, we analyze the operation of the system above the lasing threshold. We show that below a critical value of the Fröhlich constant, the laser can only operate in the conventional regime: namely, there are coherent cavity photons but no coherent phonons. Above the critical value, a new pump rate threshold appears. Above this threshold, either joint self-oscillations of coherent phonons in the gain medium and photons in a cavity or a chaotic regime are established. We also find a range of the values of the Fröhlich constant, the pump rate, and the resonator eigenfrequency, in which more than one dynamical regime of the system is stable. In this case the laser dynamics is determined by the initial values of the resonator field, the active medium polarization, the population inversion, and phonon amplitude.
我们报道了一种增益介质具有大拉曼散射截面的激光器的异常工作模式，这种情况在新型增益介质中很常见，比如胶体量子点、外延量子点和钙钛矿材料。这些介质的特点是具有强电子 - 声子耦合。利用弗罗利希哈密顿量来描述此类介质中的电子 - 声子耦合，我们分析了系统在激光阈值以上的工作情况。我们表明，在弗罗利希常数的临界值以下，激光器只能在传统模式下工作：即存在相干腔光子，但不存在相干声子。在临界值以上，会出现一个新的泵浦速率阈值。高于此阈值，增益介质中的相干声子与腔中的光子会发生联合自激振荡，或者进入混沌状态。我们还发现了弗罗利希常数、泵浦速率和谐振器本征频率的一系列取值范围，在这个范围内系统的多种动力学模式都是稳定的。在这种情况下，激光动力学由谐振器场的初始值、激活介质极化、粒子数反转和声子振幅决定。
