JPH1079550A - Solid laser device of exciting semiconductor laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a solid laser device which is capable of supplying a laser beam of high quality and high power by a method, wherein a plurality of laser beam generating sections of edge surface exciting type are provided, and a second mirror is provided at the intersection of the optical axes of the laser beams emitted from the beam generating sections. SOLUTION: Laser beam generating sections 7, each composed of a laser medium 2, a semiconductor laser 1 which excites the laser medium 2 on its optical axis, and a first mirror 5 high in reflectance to a laser beam emitted from the laser medium 2 are provided. A Q switch device 3 which turns a laser beam emitted from the laser medium 2 into giant pulses and a nonlinear optical crystal 4 which multiplies a laser beam of giant pulses in wavelength are provided. Furthermore, a second mirror 6 which is high in transmittance to a laser beam multiplied in wavelength and high in reflectance to a laser beam emitted from the laser medium 2 is provided at an irntersection of the optical axes of the laser beam generating sections 7, so as to make the axes of reflected laser beams coincide with the optical axes of the other laser beam generating sections 7 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state laser device using a semiconductor laser as an excitation light source.

[0002]

2. Description of the Related Art For example, in a laser device using a semiconductor laser as an excitation light source, a laser medium arranged on the optical axis of the obtained laser beam is moved from the semiconductor laser arranged on the optical axis to the end face of the laser medium. An end-pumping method of irradiating laser light toward the laser beam, and irradiating the laser medium on the optical axis of the obtained laser light from the semiconductor laser arranged on the side thereof toward the optical axis of the laser medium There is a side excitation method.

The configuration of a conventional end-pumped laser apparatus will be described with reference to FIG.
2 is a laser medium, 13 is a Q-switch element that makes a laser beam emitted from the laser medium 12 a giant pulse,
Reference numeral 14 denotes a nonlinear optical crystal that multiplies the wavelength of the giant pulse laser beam. Reference numeral 15 denotes a first mirror disposed coaxially between the semiconductor laser 11 and the laser medium 12, and has a high reflectance for laser light emitted from the laser medium 12. Reference numeral 16 denotes a second mirror disposed coaxially outside the nonlinear optical crystal 14,
Has a high transmittance with respect to the laser light multiplied by, and has a high reflectance with respect to the laser light emitted from the laser medium 12.

[0004]

By the way, the end face pumping method as shown in FIG. 2 has high quality of the obtained laser light,
The oscillation efficiency of the obtained laser light is also good. On the other hand, in the side-surface pumping method, the irradiation area of the semiconductor laser as the pumping light source can be increased, so that high-output laser light can be obtained. However, the end face pumping method has a problem that the irradiation area of the semiconductor laser which is the pump light source is small and high output cannot be achieved. On the other hand, the side-pumping method has a problem that the oscillation efficiency of the obtained laser light is poor and the quality of the obtained laser light is poor.

An object of the present invention is to provide a semiconductor laser-excited solid-state laser device capable of supplying high-quality laser light with high quality in view of the above-mentioned conventional problems.

[0006]

According to the present invention, there is provided a semiconductor laser-excited solid-state laser device comprising: a laser medium; a semiconductor laser for exciting the laser medium from an optical axis thereof; and a laser medium disposed between the semiconductor laser and the laser medium. A plurality of laser light generating sections each including a first mirror having a high reflectance for the emitted laser light, a Q-switch element for making the laser light emitted from the laser medium a giant pulse, and a giant pulse A nonlinear optical crystal that multiplies the wavelength of the laser light, a high transmittance for the wavelength of the multiplied laser light, a high reflectance for the wavelength of the laser light emitted from the laser medium, and a plurality of And a second mirror disposed at the intersection of the optical axes of the laser light generating sections so that the reflected optical axis coincides with the optical axis of the other side. Quality of the laser beam so that remain in increasing the output power of good by providing a plurality of laser light generating portion.

Preferably, the second mirror reflects the laser light emitted from the laser medium with a high reflectance in the 90 ° direction, and has a high transmittance with respect to the wavelength of the multiplied laser light, A plurality of laser generators are arranged in an L-shape.

Further, when the first mirror is formed of a vapor-deposited film formed on the side of the laser medium on which the laser beam from the semiconductor laser is incident, the first mirror can be simply and inexpensively formed.
In addition, when the nonlinear optical crystal is disposed at a position that bisects the optical path between the plurality of laser light generating units, the first mirror is configured by a concave mirror and the laser light is converged by the nonlinear optical crystal. When improving the wavelength conversion efficiency, it is possible to improve the wavelength conversion efficiency by using mirrors having the same radius of curvature as the first mirrors at both ends of the optical path.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the semiconductor laser pumped solid-state laser device of the present invention will be described below with reference to FIG.

In FIG. 1, reference numeral 1 denotes a semiconductor laser, and 2 denotes a laser medium.
Constitutes the laser light generator 7. Further, a first mirror 5 having a high reflectance for laser light emitted from the laser medium 2 is disposed coaxially between the semiconductor laser 1 and the laser medium 2 of the laser light generating unit 7. ing. The pair of laser light generators 7 are arranged in an L-shape such that their optical axes intersect at an intersection angle of 90 °. Since the laser medium 2 is provided with a pair of laser light generators 7, the end faces thereof are cut at right angles to the optical axis so that their optical axes can be easily adjusted.

Reference numeral 3 denotes a Q-switch element arranged coaxially with the optical axis of one of the laser light generating units 7, which converts the laser light emitted from the laser medium 2 into a giant pulse. Numeral 4 is a non-linear optical crystal arranged coaxially with the optical axis of one of the laser light generating sections 7 for multiplying the wavelength of the giant pulse laser light. The nonlinear optical crystal 4 is disposed at a position that bisects the optical path between the two laser light generators 7, 7, and the first mirror 5 in the two laser light generators 7, 7 converts the laser light into the nonlinear light. The optical crystal 4 is configured by a concave mirror so as to converge.

Reference numeral 6 denotes a second mirror arranged at a position where the optical axes of the plurality of laser light generating sections 7 intersect with each other and inclined at 45 ° to both optical axes. It has a high transmittance to the emitted laser light, and has a high reflectance in a 90 ° direction to the laser light emitted from the laser medium 2 of both laser light generators 7.

In the above configuration, a plurality of laser light generating units 7 each comprising an end-pumped semiconductor laser 1 and a laser medium 2 are provided to provide a high transmittance for the wavelength of the laser light multiplied by the nonlinear optical crystal 4. A second mirror 6 having a high reflectance with respect to the wavelength of the laser light emitted from the laser medium 2, and having a reflected optical axis at the intersection of the optical axes of both laser light generating sections 7 with the optical axis of the other side. , The two laser light generators 7 of the end-pumping type are excited in two stages, and are made giant pulses by the Q switch element 3.
Laser light whose wavelength has been multiplied by the nonlinear optical crystal 4 is output, and high output can be achieved while maintaining good laser light quality, which is a feature of the end-pumped laser apparatus. Further, since the laser medium 2 is not Brewster-cut, the adjustment of the optical axis is easy. Further, when the first mirror 5 is formed of a concave mirror so that the laser light is converged on the nonlinear optical crystal 4, the wavelength conversion efficiency can be increased, and the nonlinear optical crystal 4 can be formed by a laser light generating unit. Since the optical path between 7 and 7 is arranged at a position that bisects the optical path,
The effect can be obtained by using the first mirrors 5 having the same radius of curvature.

In the above-described embodiment, the first mirror 5 is constituted by an independent mirror. However, the first mirror 5 is constituted by a vapor deposition film formed on the side of the laser medium 2 on which the laser beam from the semiconductor laser 1 is incident. Alternatively, the laser light generator 7 can have a simpler configuration. In addition, although an example in which a pair of laser generators 7 is provided has been described, three or more laser generators 7 may be provided.

[0015]

According to the semiconductor laser-excited solid-state laser device of the present invention, as is apparent from the above description, a plurality of edge-pumped laser light generating sections are provided, so that the quality of the laser light remains good. And a large laser light output can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of one embodiment of a semiconductor laser pumped solid-state laser device of the present invention.

FIG. 2 is a configuration diagram of a conventional semiconductor laser pumped solid-state laser device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor laser 2 Laser medium 3 Q switch element 4 Nonlinear optical crystal 5 First mirror 6 Second mirror 7 Laser light generation part

Claims (4)

[Claims] 1. A laser medium, a semiconductor laser for exciting the laser medium from the optical axis thereof, and a first laser disposed between the semiconductor laser and the laser medium and having a high reflectance with respect to laser light emitted from the laser medium. A plurality of laser light generating sections each including a mirror, a Q-switch element that converts the laser light emitted from the laser medium into a giant pulse, and a nonlinear optical crystal that doubles the wavelength of the giant pulse laser light. Has a high transmittance with respect to the wavelength of the laser light emitted from the laser medium, has a high reflectance with respect to the wavelength of the laser light emitted from the laser medium, and has a reflected optical axis at the intersection of the optical axes of the plurality of laser light generating sections. And a second mirror disposed so as to coincide with the optical axis of the other party. 2. The second mirror reflects the laser light emitted from the laser medium at a high reflectance in the 90 ° direction and has a high transmittance with respect to the wavelength of the multiplied laser light.
2. The solid-state laser pumped solid-state laser device according to claim 1, wherein the plurality of laser generators are arranged in an L-shape. 3. The semiconductor laser-excited solid-state laser device according to claim 1, wherein the first mirror is formed of a vapor-deposited film formed on a laser medium incident side of a laser beam from a semiconductor laser of a laser medium. . 4. The semiconductor laser-excited solid-state laser device according to claim 1, wherein the nonlinear optical crystal is disposed at a position that bisects an optical path between the plurality of laser light generating units.