High-Peak-Power Passively Q-Switched Laser at 589 nm with Intracavity Stimulated Raman Scattering

Abstract

A novel scheme was developed for a diode-pumped passively Q-switched Nd:YVO4/KGW Raman laser at 589 nm with a diode-to-orange conversion efficiency reaching 11.4%. The compact near-concentric cavity was designed to achieve the criterion of good passive Q-switching and to contain a coupled resonator for intracavity stimulated Raman scattering (SRS) and second harmonic generation (SHG). The dependence of the output performance on the initial transmission of the saturable absorber was explored in detail. Furthermore, the output performance was studied by considering the influence of the pump-to-mode size ratio. By using an initial transmission of 50%, the highest pulse energy and peak power were 110 μJ and 118 kW, respectively, at a pump duration of 40 μs and a pump frequency of 10 kHz.

Sub-Nanosecond Passively Q-Switched Yellow and Orange Raman Lasers

“…The peak powers for the yellow and orange outputs are up to approximately 176 and 138 kW, respectively. In previous results, the obtained peak powers for yellow-orange lasers were approximately 81.4 W [14], 16 kW [15], and 118 kW [23]. To the best of our knowledge, these peak powers are the highest values obtained in sub-nanosecond passively Q-switched yellow and orange lasers.…”

“…By 2021, the efficiency had increased to approximately 80% with a light intensity of 10 18-19 W/cm 2 [35], demonstrating LBO's great potential in high energy density applications. In this work, the optimal cavity length is systematically explored to generate a sub-nanosecond pulse duration to surpass previous works [14][15][16]23]. Under the optimal circumstance, the highest pulse energy and shortest pulse width for the yellow output are found to be 118 µJ and 0.67 ns, respectively.…”

“…Not only the continuous-wave and quasi-continuous-wave operation [20][21][22] but also the actively and passively Q-switched yellow-orange lasers have been widely investigated [23,24]. Compared with active Q-switched operation, passive Q-switched solid-state lasers have the advantages of compactness, simplicity, and robustness [25,26].…”

“…Previously, we used a near-concentric cavity to realize an efficient passively Q-switched Nd:YVO 4 Raman laser at 589 nm with a KGW as an intracavity Raman gain medium at the shift of 901 cm −1 [23]. For achieving a passive Q-switching efficiency [30], we employed a near-concentric resonator to generate a large value of α via the beam focusing on the saturable absorber.…”

Top-seeded solution growth, spectral analysis and laser properties of a novel Nd-doped Bi2Mo2.66W0.34O12 crystal

“…22–27 Besides, crystals in this family were also observed to have large third-order nonlinear susceptibility for stimulated Raman scattering (SRS) and have been demonstrated as efficient Raman shifters, examples can be seen in molybdates, like SrMoO 4 , 28 CaMoO 4 , 28 and PbMoO 4 , 28,29 and tungstates, like BaWO 4 , 30–33 SrWO 4 , 34 and KGd(WO 4 ) 2 . 35–41 Combining both the outstanding performances as laser host and Raman laser materials, rare-earth doped scheelite crystals can be used for generating self-stimulated Raman lasers. 42 In addition, crystals of this family are usually very prone to fracture along a specific crystallographic plane, making the crystals in this family promising materials for microchip lasers.…”