JPH04186888A - Semiconductor laser excitation solid laser - Google Patents

Abstract

PURPOSE:To make it possible to enhance the absorptivity of semiconductor laser light extremely and further operate a Q-switch of a solid laser by installing a semiconductor laser light incident section which has a nonreflective coat surface against the semiconductor laser light and moreover includes no laser active ions to the side of a cylinder-shaped solid laser medium. CONSTITUTION:A semiconductor laser incident section 20 is installed in the side of a solid laser medium 6 which laser light from a semiconductor laser 1 enters. This incident section 20 has a nonreflective coat surface against the wavelength of laser light from the semiconductor laser 1 and comprises a material which contains no laser active ions. An output mirror 3 is installed on the axis of a cylinder-shaped solid laser medium on the left while a whole reflected mirror 4 is installed thereto on the right respectively. In front of the whole reflected mirror 4 is installed a Q switch operation unit 5 which comprises an acousto optical device and an optoelectric device or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to solid-state lasers, and more particularly to solid-state lasers based on semiconductor lasers.

[Conventional technology]

FIGS. 3 and 4 show an example of a conventional semiconductor laser-excited solid-state laser. FIG. 3 is a side view of this solid-state laser, and FIG. 4 is a sectional view taken along line A-A. 1 is a semiconductor laser, which is a light source for exciting a solid-state laser. The semiconductor laser light emitted from this semiconductor laser enters the inside of the cylindrical solid-state laser medium 2 from the side surface, and in the process of passing through the medium 2, the semiconductor laser light is absorbed and excites the solid-state laser medium 2.

The semiconductor laser light that has passed through once and not been absorbed is reflected by the reflector 3, passes through the inside of the medium 2 again, and is absorbed. Then, it is optically excited by this semiconductor laser light,
A solid-state laser beam is generated by a solid-state laser medium 2 serving as a gain medium for the solid-state laser beam, and a laser resonator formed by an output mirror 4 and a total reflection mirror 5. In addition, the fourth
In the figure, a indicates the optical axis of the solid-state laser beam in the solid-state laser medium 2.

[Problem to be solved by the invention]

In such a conventional semiconductor laser pumped solid-state laser, as shown in FIG. This angle of reflection does not change from the angle at which the semiconductor laser light enters the medium 2 to the angle of total reflection. Therefore, in order to reflect the semiconductor laser beam, to ensure a sufficient optical path length (absorption length) of the semiconductor laser beam within the medium 2, and to perform efficient optical excitation, it is necessary to install a reflector 3 made of, for example, metal vapor deposition on the surface of the medium 2. Alternatively, it is necessary to provide a total reflection coating using a dielectric multilayer film.

However, in the case of a reflector made of metal vapor deposition, its reflectance is about 90%, and the intensity of the semiconductor laser light rapidly decreases due to multiple reflections, which causes a problem in that the absorption efficiency of the semiconductor laser light by the solid dozer medium decreases. There is. Also, in the case of total reflection coating using dielectric multilayer film,
It is technically difficult to control the film thickness on a curved surface, and the reflectance of the coated surface partially decreases, causing the same problems as with reflectors made of metal vapor deposition.

An object of the present invention is to solve the second problem and provide a semiconductor laser-excited solid-state laser in which the absorption rate of semiconductor laser light in a solid-state laser medium is extremely high.

Another object of the present invention is to provide a semiconductor laser-excited solid-state laser that further enables Q-switch operation of the solid-state laser.

[Means to solve the problem]

A first aspect of the present invention is a semiconductor laser-excited solid-state laser in which a semiconductor laser beam is incident on a cylindrical solid-state laser medium, and the solid-state laser medium is optically excited to generate a solid-state laser beam. The present invention is characterized in that a semiconductor laser light incident portion that has a cylindrical shape and does not contain laser active ions is provided on a side surface of the cylindrical solid-state laser medium.

A second invention is a semiconductor laser-excited solid-state laser in which a semiconductor laser beam is incident on a cylindrical solid-state laser medium, and the solid-state laser medium is optically excited to generate a solid-state laser beam. A semiconductor laser light incident part that has a semiconductor laser beam and does not contain laser active ions is provided on a side surface of the cylindrical solid-state laser medium, and a total reflection mirror that constitutes a laser resonator for laser light generated in the cylindrical solid-state laser medium and the solid state A feature is that a Q-switch operating unit is provided between the laser medium and the laser medium.

〔Example〕

Next, examples of the present invention will be described. FIGS. 1 and 2 show an example of a semiconductor laser excitation fixing device according to the first and second inventions. FIG. 1 is a sectional view of this solid-state laser, and FIG. 2 is a side view as seen from the direction of arrow B. Reference numeral 1 denotes a light source for exciting a solid-state laser, which is a semiconductor laser. Reference numeral 6 denotes a solid laser medium into which the laser light from the semiconductor laser 1 is incident, and a semiconductor laser incidence section 2 is provided on the side surface of the solid laser medium.
It is set to 0. The entrance portion 20 has a non-reflection coated surface for the wavelength of the laser beam from the semiconductor laser 1 and is formed of a material that does not contain laser active ions. Further, the direction of the entrance surface 20a of the entrance section 20 is set so that when the laser light that is incident perpendicularly to this surface enters the solid-state laser medium 6, the incidence is oblique to the circumferential direction of the medium 6. .

As shown in FIG. 2, on the axis of the cylindrical solid-state laser medium 6, an output mirror 3 is provided on the left hand, and a total reflection mirror 4 is provided on the right hand. optical element,
Q switch operation unit 5 composed of electro-optical elements etc.
Or is provided.

In such a semiconductor laser pumped solid-state laser, when the semiconductor laser 1 emits laser light, it enters the fixed laser medium 6 through the non-reflection coated surface of the semiconductor laser light incidence section 20. Since this semiconductor laser light 10 is incident obliquely to the circumferential direction of the cylindrical medium 6, when it passes through the inside of the medium 6 and reaches the side surface, it is totally reflected there, and thereafter, the total reflection is repeated. It is confined inside the medium 6. Since the semiconductor laser beam 10 is thus totally reflected on the side surface of the medium 6, its reflectance is 100%, and as a result, the absorption length is sufficient and the absorption rate of the semiconductor laser beam in the solid-state laser medium 6 is extremely high. Become.

The solid-state laser beam is then optically excited by the confined semiconductor laser beam and is formed by the solid-state laser medium 6, which serves as a gain medium for the solid-state laser beam, and the laser resonator constituted by the output mirror 3 and the total reflection mirror 4. Occur.

Furthermore, in this semiconductor laser pumped solid-state laser, Q-switch operation of the solid-state laser is possible by operating the Q-switch operation unit 5.3 [Effect of the Invention] As explained above, the first invention has a cylindrical In a semiconductor laser-excited solid-state laser in which a semiconductor laser beam is incident on a solid-state laser medium and the solid-state laser medium is optically excited to generate a solid-state laser beam, the semiconductor has a non-reflection coated surface for the semiconductor laser beam and does not contain laser-active ions. A laser beam incidence section is provided on the side surface of the cylindrical solid-state laser medium.

Therefore, it is possible to enter the semiconductor laser light from the semiconductor laser light incidence part, cause it to be totally reflected on the side surface of the solid-state laser medium with a reflectance of 100%, and confine it inside the medium.
Extremely high absorption rate of semiconductor laser light can be achieved.

Furthermore, as a result, even if the mismatch between the wavelength of the semiconductor laser light and the center wavelength of absorption by the solid-state laser medium is large,
Since the absorption rate of semiconductor laser light is high, temperature control of the semiconductor laser can be relaxed, and the burden on the semiconductor laser cooling system can be reduced.

In addition, since the optical path of the semiconductor laser light within the cylindrical solid-state laser medium is concentrated near the surface of the cylindrical solid-state laser medium,
Semiconductor laser light is absorbed mainly near the surface of the solid-state laser medium, and heat generation of the solid-state laser medium also occurs near the surface. Therefore, the solid-state laser medium can be efficiently cooled, and the lens effect of the solid-state laser and the laser medium can be reduced, so a high-quality laser beam can be generated with high efficiency, and the device can be made smaller.

The semiconductor laser-excited solid-state laser according to the second invention further includes a Q-switch operation unit, so that Q-switch operation of the solid-state laser is also possible.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a semiconductor laser pumped solid-state laser according to the invention, FIG. 2 is a side view of the semiconductor laser pumped solid-state laser of FIG. 1, and FIG. 3 is an example of a conventional semiconductor laser pumped solid-state laser. 4 is a sectional view of the semiconductor laser pumped solid-state laser shown in FIG. 3; FIG. 5 is an enlarged sectional view of the semiconductor laser pumped solid-state laser shown in FIG. 3. 1... Semiconductor laser 3... Output mirror 4... Total reflection mirror 5... Q switch operation unit 6... Solid laser medium 20... Semiconductor laser light incidence Department Agent Patent Attorney Yoshiyuki Iwasa Figure 1 Figure 2 Division Figure 3 Figure 4

Claims (2)

[Claims] (1) A semiconductor laser-excited solid-state laser in which a semiconductor laser beam is incident on a cylindrical solid-state laser medium to optically excite the solid-state laser medium to generate a solid-state laser beam, which has a non-reflection coated surface for the semiconductor laser beam, and 1. A semiconductor laser-excited solid-state laser, characterized in that a semiconductor laser light incidence section that does not contain laser active ions is provided on a side surface of the cylindrical solid-state laser medium. (2) A semiconductor laser-excited solid-state laser in which a semiconductor laser beam is incident on a cylindrical solid-state laser medium to optically excite the solid-state laser medium to generate a solid-state laser beam, which has a non-reflection coated surface for the semiconductor laser beam, and A semiconductor laser light incident part that does not contain laser active ions is provided on a side surface of the cylindrical solid-state laser medium between a total reflection mirror that constitutes a laser resonator for laser light generated in the cylindrical solid-state laser medium and the solid-state laser medium. A semiconductor laser-excited solid-state laser characterized by being provided with a Q-switch operation unit.