Diode-pumped multi-frequency Q-switched laser with intracavity cascade Raman emission

Abstract

A diode-pumped actively Q-switched mixed Nd:Y(0.3)Gd(0.7)VO(4) laser with an intracavity KTP crystal is developed to produce cascade SRS emission up to the fourth order. With an incident pump power of 14 W and a repetition rate of 50 kHz, the average output powers at the first, second, third and fourth Stokes modes are approximately 0.05 W, 0.61 W, 0.25 W, and 0.11 W, respectively. The maximum peak power is greater than 2 kW.

Synchronized generation of 1534 and 1572 nm by the mixed optical parameter oscillation

“…Pulse repetition rate, kHz 9 Figure 5 (online color at www.lphys.org) Pulse widths and repetition rates with respect to the incident LD pump power for two couplers and 5.5 -3.9 ns for the output coupler 1 and coupler 2, respectively.…”

“…The frequency conversions based on the nonlinear crystals have been validated as efficient approaches for the multiple-wavelength emission, such as the cascaded second-order χ (2) [8], thirdorder χ (3) [9], and χ (2) + χ (3) conversion processes [10]. However, these conversion processes have a common disadvantage that the subsequent conversion is always based on the completion of the former process.…”

Simultaneous intracavity optical parametric oscillation and stimulated Raman scattering pumped by a doubly passively Q-switched Nd:GGG laser

“…Up to date, several approaches have been successfully used to obtain simultaneous multi-wavelength emissions, in which the frequency conversion based on a nonlinear crystal has been proved to be an efficient way. By using the second-order nonlinearity v (2) [1] and the third-order nonlinearity v (3) [2], multi-wavelength radiations have been realized. Especially, the combination of using v (2) and v (3) in a single nonlinear crystal has received much attention recently [3][4][5][6][7].…”

“…As a conventional nonlinear crystal, KTiOPO 4 (KTP) crystal has been used for the effects arising from the second-order nonlinearity v (2) , such as second-harmonic generation, sum-and difference-frequency generation and optical parametric processes. On the other hand, a strong Raman scattering shift near 270 cm -1 indicates that KTP crystal could be used for stimulated Raman scattering (SRS) conversion, which is related to the third-order nonlinearity v (3) [8].…”

“…On the other hand, a strong Raman scattering shift near 270 cm -1 indicates that KTP crystal could be used for stimulated Raman scattering (SRS) conversion, which is related to the third-order nonlinearity v (3) [8]. With the combination of the v (2) and v (3) effects, Y. Chen first reported SRS, self-sum frequency mixing (SFM) and self-frequency doubling (SFD) processes in a single KTP crystal [9]. Based on a periodically poled KTP (PPKTP) crystal, V. Pasiskevicius et al [10] realized optical parametric oscillation (OPO) and subsequent SRS conversions, even though the SRS process would limit the OPO conversion efficiency .…”