High repetition rate electro-optical cavity-dumped Nd:GdVO4 laser

This paper presents an experimental study of an electro-optical cavity-dumped Nd:GdVO4 laser. A V-type cavity was used because of its higher extinction ratio and lower losses in s-wave oscillation mode when compared with a linear cavity. The LD pumping source of 808 nm and 879 nm were fiber coupled with core diameter of 400 μm and numerical aperture of 0.22. Two achromatic lenses were employed to re-image the pump beam into the crystal with a spot diameter of about 640 μm. The total dimensions of composite YVO₄/Nd:GdVO₄ and GdVO₄/Nd:GdVO₄ crystals were same and they were 3×3×10 mm³, and the undoped caps was 2 mm long. The doped part had a Nd³⁺ ion concentration of 0.3 at.%. The RTP Pockels cell was used as the Q-switch and the rise and fall times of the driver were both ~3.5 ns. A thin-film polarizer (TFP) and a quarter wave plate (QWP) were employed in the experiment. The cavity length was 190 mm and 175 mm for YVO4/Nd:GdVO⁴ laser pumped by 808 nm LD and GdVO4/Nd:GdVO4 laser pumped by 879 nm LD, respectively.The maximum stable repetition rate was 50 kHz and 100 kHz for YVO₄/Nd:GdVO₄ laser pumped by 808 nm LD and GdVO₄/Nd:GdVO₄ laser pumped by 879 nm LD, respectively. The pulse width remained constant at 3.8±0.2 ns for the two lasers. The peak power was 30.8 kW and 34.4 kW for the stable repetition rate of 50 kHz and 100 kHz of the two lasers, respectively.