Efficient second harmonic generation of double-end diffusion-bonded Nd:YVO_4 self-Raman laser producing 79 W yellow light

Abstract

A high power and efficient 588 nm yellow light is demonstrated through intracavity frequency doubling of an acousto-optic Q-switched self-frequency Raman laser. A 30-mm-length double-end diffusion-bonded Nd:YVO(4) crystal was utilized for efficient self-Raman laser operation by reducing the thermal effects and increasing the interaction length for the stimulated Raman scattering. A 15-mm-length LBO with non-critical phase matching (theta = 90 degrees, phi = 0 degrees) cut was adopted for efficient second-harmonic generation. The focus position of incident pump light and both the repetition rate and the duty cycle of the Q-switch have been optimized. At a repetition rate of 110 kHz and a duty cycle of 5%, the average power of 588 nm light is up to 7.93 W while the incident pump power is 26.5 W, corresponding to an overall diode-yellow conversion efficiency of 30% and a slope efficiency of 43%.

Thermal lens effects in the LD end-pump fundamental and self-Raman crystal laser

“…The thermal focal length of self-Raman crystal laser could be revised as i = hJI> (10) iR+ iL-h In (10), h is the distance from the principal plane of the thermal lens to the incident facet of laser crystal, which could give by h == L/2n [14] , n is the index of refraction of Self Raman crystal. The experiment results for the self-Raman laser in [12] show that the thermal focal length of self-Raman laser is much shorter than normal Nd-doped fundamental lasers for its additional thermal lens effect of Raman conversion. The thermal focal length was just concluded in the continue-wave mode, the Q-switch mode will be more complicated.…”

“…In the experiment of the self-Raman crystal laser, we found that the resonator stability was more sensitive to the pump beam waist position than custom fundamental crystal laser [12]. Self-Raman crystal laser has the advantage of eliminating the need of a separate Raman crystal and making the resonator compact.…”

Growth and Characterization of Vanadate Laser Crystals

“…Up to now, the maximum of over than 110 W continuous--wave and mode-locked Nd:YVO 4 laser has been achieved [9,10]. Besides the laser performance, Nd:YVO 4 is also a self-Raman laser crystal and the output power of 7.9 W yellow laser has been achieved with the slope eciency of 43% [11]. [12,13] with the size of 32 × 20 mm 2 .…”

Efficient CW laser at 559 nm by intracavity sum-frequency mixing in a self-Raman Nd:YVO4 laser under direct 880 nm diode laser pumping

“…Chen [4,5]. In recent years, efficient intracavity second-harmonic generation (SHG) of Q-switched and continuous wave (CW) selfRaman lasers have been widely developed [6][7][8][9][10][11][12][13][14]. But the intracavity sum-frequency generation (SFG) of the fundamental and Stokes is still seldom reported.…”