Loop laser cavities with self-pumped phase-conjugate mirrors in low-gain active media for phase-locked multichannel laser systems

High power Nd:YAG laser with self-pumped phase-conjugate loop cavity and repetitive pulsed diode-matrix side-pumping

“…1. Many passes of the laser radiation through the AE per one round-trip of the cavity lead to increasing the round-trip gain and the four-wave-mixing diffraction efficiency of the laser radiation [11,12]. The triple self-intersection of the intracavity waves allows to record twenty eight gain gratings by each pair of the waves (number of combinations for pairs of eight waves is (8 2 -8)/2 = 28), but only three gain gratings recording by the strongest output wave (in pairs with other waves) have the highest diffraction efficiency and correspondingly have effect to the phase-conjugate laser oscillation [13].…”

Passively Q-switched Nd:YAG laser with diffractive output resonator

“…Phase-conjugate mirror (PCM) concept [1][2][3] exploiting the four-wave mixing (FWM) phenomenon appears to be one of the most effective ways of extracting near diffraction-limited beams from active medium. The FWM process has been realized in several approaches in solid-state lasers in the past three decades [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Thermo-optical effects along with asymmetric temperature and gain gradients as well as heterogeneity of population inversion result in degradation of output beam quality.…”

“…It can be compensated by intracavity adaptive optics systems or by exploiting the PCM concept, which is formed inside the gain medium, creating self-adaptive resonator. Two groups of self-adaptive cavities have been studied: nonreciprocal resonators [7][8][9][10][11], in which the direction of beam propagation is forced by additional, nonreciprocal elements and reciprocal resonators [12][13][14][15][16], in which the two beams inside the cavity travel in counter-propagating directions. The most advanced result was demonstrated previously [11], with 100 mJ energy, diffraction-limited, single-frequency beam in the self-starting, self-Q-switched, diode side-pumped Nd:YAG laser being reported.…”

Side-pumped neodymium laser with self-adaptive, nonreciprocal cavity

“…Additionally, it significantly degrades the spatial quality and decreases the overall performance of the laser system. There are several techniques, i.e., injection−seeding [1,2], grazing−incidence−angle [3,4] or self−adaptive resona− tors based on phase conjugation via gain saturation mecha− nism [5][6][7][8][9][10][11][12][13][14][15], that allow to generate near−diffraction−limited beam output in the presence of a high inhomogeneity of the gain spatial profile. In this paper we demonstrate the results of a self−adaptive Nd:YAG laser with intra−cavity amplifier with an open−loop, nonreciprocal cavity containing phase conjugate mirror.…”