Semiconductor double end face pumping Nd:YV04 high power single-mode solid laser

Abstract

The invention is a semiconductor double-end-pumped Nd:YVO4 high-power single-mode solid laser, comprising two laser diodes, 45 deg mirror, two optical fibers, two optical coupling systems, Nd:yvo4 crystal, Q-switch, mirror, output mirror and cooler, and theoretically making detailed synthetic optimization design for cavity structure, thermal lens focal length, and doping concentration, damage threshold and length of Nd:YVO4 crystal. And the experiment shows that the experimental results accord with the theoretical design, perfectly.

Description

Technical field [0001] The invention relates to the technical field of lasers, and relates to an end-pumped solid-state laser. Background technique [0002] Among the pumping methods using laser diodes as laser pumping sources, the end pumping method has the advantages of simple pumping device, high coupling efficiency, good matching between pump beam and cavity mode, good quality of output laser beam and low threshold pump power. low merit. Among the many laser crystals suitable for laser diode pumping, Nd:YVO4 crystals are favored due to their large absorption coefficient, large emission cross-sectional area, high optical damage threshold, high oblique efficiency, high birefringence effect and linear polarization of radiation. Favored by people, it has become an ideal working material for laser diode pumped medium and small power lasers ("Laser Diode Pumped Efficient Nd:YVO4 / KTP Intracavity Frequency-Doubling Laser", Acta Optics Sinica, 1996, 16(10): 1393-1396 ). Howeve...

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Problems solved by technology

[0003] Among the many laser diode end-pumped Nd:YVO4 solid-state lasers, most of them use single-end pumping ("Efficient 15W CW Nd:YVO4 Solid-state Laser Single-end-pumped by a Fiber-coupled Diode-laser-array ", Chinese Journal of Lasers, 1999, Vol.B8, No.5, 385-388; "High Power Diode single-end-pumped Nd: YVO4Laser", Optics&Laser Technology, 35(2003): 445-449), due to The thermal stress generated by the thermal effect in the crystal cannot exceed the limit of the fracture stress of the Nd:YVO4 crystal, and there is a maximum pump power per unit area of ​​the gain medium ("Power scaling of diode-pumped Nd:YVO4 Lasers", IEEE J Quantum Electronics , 2002, 38(9): P1291~1299), so the pump power cannot be very high, and the obtained laser power is relatively small, so that the laser is subject to certain restrictions in practical laser applications; and if the laser crystal Nd:YVO4 doped Concentration and crystal length are not selected blindly through detailed design. Due to the poor thermal conductivity of Nd:YVO4 crystal and the obvious thermal lens effect when pumped at high power, the obtained laser power is not only low, but also the laser beam Both quality and laser stability can be severely affected

[0004] In order to obtain high power output on the end-pumped Nd:YVO4 laser, there is also a method of using a double-end pumped double-block crystal ("A Design of a High-Power End-pumped Nd:YVO4 Laser Resonator Compensating for Thermal Effects", Photon Journal of the Chinese Academy of Sciences, 2003 (12), 1418-1421), this method of increasing the number of laser crystals to reduce the pump power per unit area of ​​the laser crystal not only increases the equipment cost, but also occupies the space position of the laser. At the same time, higher requirements are put forward for the cooling device, and the difficulty of laser adjustment is also increased.

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