Yong Wei

Yellow-light generation of 5.7 W by intracavity doubling self-Raman laser of YVO 4 /Nd:YVO 4 composite

A high-power 588 nm light produced by an intracavity frequency-doubling acousto-optic Q-switched self-frequency Raman laser is reported. A 20-mm-long YVO(4)/Nd:YVO(4) composite crystal and a 15-mm-long LiB(3)O(5) (LBO) with noncritical phase-matching (theta=90 degrees , phi=0 degrees ) cut were adopted for efficient self-Raman laser operation and second-harmonic generation, respectively. By the optimizing the focus position of incident pump light and Q-switch repetition rate, yellow light with 5.7 W average power was generated under the pump power of 23.5 W, corresponding to the overall diode-yellow conversion efficiency of 24.2% and slope efficiency of 32%. The pulse width is about 16 ns, and the pulse energy is up to 95 microJ.

Efficient second harmonic generation of double-end diffusion-bonded Nd:YVO4 self-Raman laser producing 7.9 W yellow light

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%.

High-efficiency intracavity Nd:YVO 4 \KTA optical parametric oscillator with 3.6 W output power at 1.53 μm

An efficient intracavity KTA optical parametric oscillator (OPO) driven by diode-end-pumped acousto-optical Q-switched Nd:YVO(4) laser is demonstrated. The mode mismatch between fundamental cavity and OPO cavity caused by the thermal lens effect in Nd:YVO(4) crystal as the pump power increased was studied. To lessen mode mismatch, a thermal lens-like cavity mirror made of plane BK7 glass induced by idler absorption was introduced into the OPO cavity. Under a diode pump power of 20 W, a maximum 1535nm light output power of 3.6 W was achieved at the pulse repetition rate of 60 kHz, corresponding to a diode-to-signal conversion efficiency of 18%. This is the highest efficiency reported for eye-safe laser based on intracavity OPO.

Potential sodium D 2 resonance radiation generated by intra-cavity SHG of a c-cut Nd:YVO 4 self-Raman laser

Intra-cavity frequency doubling with 589 nm emission from a compact c-cut Nd:YVO4 crystal self-Raman laser was investigated. A 15-cm-length LBO with non-critical phase-matching cut (θ = 90°, ϕ = 0°) was used for efficient second-harmonic generation. At a pump power of 16.2 W and a pulse repetition frequency of 40 kHz, output power up to 2.15 W was achieved with a pulse width of 16 ns and a conversion efficiency of 13.3% with respect to the diode pump power. The center wavelength was measured to be 589.17 nm with a Half-Maximum-Full-Width of 0.2 nm, which was well in accordance with the sodium D2 resonance radiation.

Diode-side-pumped Nd:YAG laser at 1338 nm

In this Letter, a high-power diode-side-pumped Nd:YAG laser emitting at 1338 nm is described. The output characteristics of the laser using the different output couplers for both the cw mode and the Q-switched mode have been studied. With a pumping power of 555 W, the average output power decreases from 70 W at 50 kHz to 55 W (slope efficiency 21.2%, optical conversion efficiency 10%) at 5 kHz. The highest peak power is up to 73 kW with the pulse duration of 150 ns at the repetition rate of 5 kHz. When operated in cw mode, the output power of 100.5 W was achieved, corresponding with the optical slope efficiency of 36%.

Diode-Side-Pumped Acoustooptic

In this paper, a diode-side-pumped acoustooptic Q-switched 1319-nm Nd:YAG laser is described. The output characteristics under the different repetition rates and output couplers have been studied. With a pumping power of 555 W, the average output power decreases from 94 W at 50 kHz to 71 W (slope efficiency 25.2%, optical conversion efficiency 12.8%) at 5 kHz. The highest peak power is up to 95 kW with the pulse duration of 150 ns at the repetition rate of 5 kHz.

Q

We demonstrated an efficient second-Stokes Raman laser emission at 1313 nm based on self-frequency stimulated Raman scattering from a diode-end-pumped actively Q-switched YVO(4)/Nd:YVO(4)/YVO(4) laser at 1064 nm for the first time, to the authors knowledge. A double-end diffusion-bonded Nd:YVO(4) composite crystal was adopted for sufficiently improving the thermal lensing effect in the course of self-frequency stimulated Raman scattering operation. With an incident pump power of 14.6 W and a pulse repetition (PRR) of 40 kHz, a maximum average output power of 2.34 W was obtained, corresponding to an optical-to-optical conversion efficiency of 16%. Pulse width and peak power were 1.2 ns and 49 kW, respectively.

-switched 1319-nm Nd:YAG Laser

The stable compact operation in the deep ultraviolet laser at 266 nm is reported from a diode-end-pumped acoustic-optic Q-switched Nd:YVO4/KTP/BBO laser. Fourth harmonic is generated by employing multiple reflections of 532 nm light for taking full advantage of the green beam. An ultraviolet laser at 266 nm with average power of 388.5 mW is obtained with a repetition-rate of 20 kHz, a pulse width of about 59.80 ns, and the corresponding optical to optical conversion efficiency of 11.9% from green to UV. High conversion efficiency and a circular spot of 266 nm laser beam have been achieved in an unfocused beam arrangement.

Second-Stokes YVO 4 /Nd:YVO 4 /YVO 4 self-frequency Raman laser

The negative and positive thermal focal lengths for 1047xa0nm and 1053xa0nm were respectively demonstrated through analyzing different thermal lensing effects along the π- and σ-polarizations in a plane-parallel resonator. A compact and efficient diode-end-pumped 1053xa0nm Nd:YLF polarized laser is presented. As high as 11.2xa0W output power of the polarized 1053xa0nm laser has been obtained at an absorbed pump power of 22.3xa0W with an optical–optical efficiency of 50% and a slope efficiency of 53%. With the aid of a ray propagation matrix and a λ/4 wave plate, different thermal lensing effects for the π- and σ-polarizations have been theoretically analyzed and experimentally verified.

Multi-reflected enhancement of fourth harmonic DUV laser generation at 266 nm

High-power 670.7u2009nm red light was obtained by intracavity frequency doubling of a Q-switched Ndu2009:u2009YAlO3 (Ndu2009:u2009YAP) laser with a critical phase matching (θ = 85.9°, = 0°) cut LBO. Experimental configurations using V-cavity and Z-cavity have been adopted for comparison. The highest output power of 19.7u2009W was achieved in the Z-cavity with optical–optical efficiency of 4%. Compared with the laser using an Ndu2009:u2009YAG crystal, the adoption of Ndu2009:u2009YAP simplified the laser system in the absence of a solid etalon and the Brewster plate. The output power stability of the red laser was investigated and the fluctuation was lower than 3% at the output power of 18u2009W an hour.