JPH0513845A - Semiconductor laser excitation laser equipment - Google Patents

Abstract

PURPOSE:To obtain a semiconductor laser excitation laser equipment of high efficiency at a low cost wherein miniaturization and simplification of adjustment can be realized, by a method wherein conversion efficiency is increased and the number of parts is decreased by unnecessitating a condeser optical system and reducing excitation light loss due to reflection. CONSTITUTION:In a semiconductor laser pumping laser equipment, at least the following are arranged on a straight line; a semiconductor laser 1 serving as an excitation light source, a rod type solid laser medium 3 exhibiting optical amplification effect, and a pair of reflecting mirrors constituting a resonator. At least one end surface 9 of the solid laser medium is constituted of a plurality of different kinds of surfaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser pumped laser device, and more particularly to improvement of the end face of a solid laser medium.

[0002]

2. Description of the Related Art Generally, a semiconductor laser pumping laser device using a semiconductor laser as a pumping light source can be roughly classified into a side pumping system and an end face pumping system. In the end face pumping type semiconductor laser pumped laser device, a focusing optical system including a lens is used to focus the output light from the semiconductor laser, for example, a laser diode, on a solid laser medium. This is because the output light from the laser diode has a large divergence angle, and the solid-state laser medium cannot be efficiently irradiated with the excitation light. That is,
A conventional semiconductor laser excitation laser device is configured as shown in FIG. 3, and includes a laser diode 1, a condensing optical system 2 for condensing the output light of the laser diode 1 in a rod-shaped solid laser medium described later, and an optical amplifier. The rod-shaped solid-state laser medium 3 that produces the effect and the output mirror 4 that is one of the pair of reflecting mirrors that form the resonator are arranged in a straight line.

The incident side end surface 5 of the solid laser medium 3 also serves as the other of the pair of reflecting mirrors. In the figure, reference numeral 6 is the exit side end surface of the solid laser medium 3, 7 is an excitation light optical path, and 8 is an output. The light path. The incident side end surface 5 and the emitting side end surface 6 of the solid-state laser medium 3 are made of one kind of flat surface.

[0004]

However, in the conventional semiconductor laser excitation laser device as described above, the fact that the excitation light receives a loss due to reflection or the like when passing through the condensing optical system 2 is a non-reflection treatment. Even with the optical components that have been subjected to, it was inevitable to some extent. Also, this condensing optical system 2
Adjustment of was complicated and was a factor of increasing the number of parts.

Therefore, a method in which the laser diode 1 is mounted close to the solid-state laser medium 3 without using the condensing optical system 2 and the excitation light is irradiated into the solid-state laser medium 3 without using the optical system is also used. Has been. However, in this method, although the optical system is not used, the loss is reduced, but since the excitation light optical path 7 is uncontrollable, the light collection efficiency is likely to be decreased, which is different from the method using the light collection optical system 2. It had the drawback of being difficult to use.

The present invention provides a semiconductor laser pumped laser device capable of reducing the loss due to reflection, reducing the number of parts, and downsizing the oscillator without the need of using a focusing optical system. To aim.

[0007]

According to the present invention, at least a semiconductor laser serving as an excitation light source, a rod-shaped solid-state laser medium that produces an optical amplification effect, and a pair of reflecting mirrors that form a resonator are arranged in a straight line. Also, at least one end face of the solid-state laser medium is a semiconductor laser pumped laser device including a plurality of different types of faces.

[0008]

According to the present invention, since it is not necessary to use a condensing optical system and the loss of the excitation light due to reflection can be reduced, the conversion efficiency can be improved. Further, since the number of parts can be reduced, downsizing and simplification of adjustment can be realized, and an inexpensive and highly efficient semiconductor laser pumped laser device can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The semiconductor laser pumped laser device according to the present invention is configured as shown in FIG. 1, and the same parts as those in the conventional example (FIG. 3) are designated by the same reference numerals.

That is, a semiconductor laser, for example, a laser diode 1 serving as an excitation light source is arranged on a straight line at a predetermined interval,
The rod-shaped solid-state laser medium 3 that provides the optical amplification effect and the output mirror 4 that is one of the pair of reflecting mirrors that form the resonator are
It is arranged.

In this case, the incident side end face 9 and the emitting side end face 10 of the solid-state laser medium 3 are both shown in FIGS. 2 (a) and 2 (b).
As is clear from the above, a plurality of surfaces of different types, for example, 2
It consists of two sides. That is, the central flat surfaces 9a, 1
0a and curved surfaces 9b and 10b of the peripheral portion, and the curved surfaces 9b and 10b are a part of spherical surfaces. The incident side end surface 9 of the solid-state laser medium 3 also serves as the other of the pair of reflecting mirrors. Next, the reason why the incident-side end surface 9 and the outgoing-side end surface 10 are composed of a plurality of different kinds of surfaces will be described.

For simplification of explanation, the pumping light incident side of the solid-state laser medium 3 is subjected to anti-reflection treatment for the wavelength of the pumping light, and for the light (output light) of the wavelength amplified and oscillated by the solid-state laser medium 3. Total reflection processing is done,
Further, it is assumed that the other end face (outgoing side) is subjected to total reflection processing for the wavelength of the excitation light and non-reflection processing for the wavelength of the output light.

Now, considering the divergence angle of the output light of the laser diode 1 on the pumping light incident side, it is polished into a spherical surface having a curvature such that it is not diverged and is condensed inside the solid-state laser medium 3. Suppose In addition, the emitting side is assumed to be a spherical surface that reflects the excitation light so that it is condensed again on the solid-state laser medium 3 without diverging. Here, if the curvatures of the spherical surface on the incident side and the spherical surface on the outgoing side are appropriately selected, it is possible to easily find the curvatures of both end surfaces for efficient excitation.

However, in the case of a commonly used semiconductor laser pumped laser device, since the incident side end face is a reflecting mirror for output light, if the end face has a curvature to function as a lens, the oscillation condition is satisfied. It was difficult to make the resonator conditions different.

Therefore, in the present invention, as described above, the incident side end face 9 and the emitting side end face 10 of the solid-state laser medium 3 are formed by a plurality of different kinds of faces.
Only the central portions of the flat surfaces 9a, 10a or curved surfaces having a relatively small curvature, and only the peripheral portions thereof are curved surfaces 9b, 10b.
As a result, it becomes possible to efficiently collect the excitation light and satisfy the oscillation condition. As a result, it is not necessary to use a condensing optical system as in the prior art, the loss due to reflection is small, the number of parts can be reduced, and the oscillator can be miniaturized.

In the above embodiment, both the end faces 9 and 10 on the incident side and the emission side are both polished to have two curved surfaces, but either one may be polished. Further, although the curved surface is a spherical surface, any surface may be used. Further, one of the reflecting mirrors is the incident side end face 9 of the solid-state laser medium 3, but a reflecting mirror may be used separately from the solid-state laser medium 3. However, in this case, the incident-side end face 9 of the solid-state laser medium 3 is subjected to the non-reflection condition processing for the output light. Further, the optical path of the excitation light shown in the figure is one example, and any optical path may be used.

[0017]

As described above, according to the present invention, it is not necessary to use a condensing optical system and the loss of excitation light due to reflection can be reduced, so that the conversion efficiency can be improved. .. Further, since the number of parts can be reduced, the miniaturization and the simplification of adjustment can be realized, and an inexpensive and highly efficient semiconductor laser excitation laser device can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a semiconductor laser pumped laser device according to an embodiment of the present invention.

2A and 2B are a side view and a front view showing a main part (solid-state laser medium) of the semiconductor laser pumped laser device of the present invention.

FIG. 3 is a configuration diagram showing a conventional semiconductor laser pumped laser device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser diode (semiconductor laser), 3 ... Solid-state laser medium, 4 ... Output mirror, 9 ... Incident side end surface, 10 ... Emission side end surface, 9a, 10a ... Flat surface, 9b, 10b ... Curved surface.

Claims (1)

Claim: What is claimed is: 1. A semiconductor laser which serves as an excitation light source, and a rod-shaped solid-state laser medium which produces an optical amplification effect.
In a semiconductor laser pumped laser device in which a pair of reflecting mirrors constituting a resonator are arranged in a straight line, at least one end surface of the solid-state laser medium is composed of a plurality of different types of semiconductors. Laser pumped laser equipment.