JPH05121802A - Semiconductor pumped solid state laser - Google Patents

Abstract

PURPOSE:To obtain a semiconductor excitation solid-state laser which can produce a plurality of solid-state laser beams using a single solid-state laser medium. CONSTITUTION:An excited beam 2 from semiconductor lasers 11 and 12 is directly incident on an end surface 32 of a thin planar solid-state laser medium, and a plurality of resonators are constituted between the end surface 32 of the solid-state laser medium and a partial reflecting mirror 5 using plane micorolenses 61, 62, 63 and 64.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor-pumped solid-state laser for generating a large number of laser beams from one solid-state laser medium using a semiconductor laser as a pump source.

[0002]

2. Description of the Related Art FIG. 5 is a schematic configuration diagram of a semiconductor-pumped solid-state laser in which a semiconductor laser is arranged in close proximity to a laser medium having a small cross section, as shown in "Laser Research Vol. 18 No. 8 (1990) P622-627". Is shown. In the figure, 1 is a semiconductor laser that generates excitation light, 2 is excitation light, and 3 is a solid-state laser medium, for example, 5 mm long and 2 wide.
mm, 0.5 mm thick rectangular cross section Nd: YAG (Y
_3-x Nd _x Al ₅ O ₁₂ ) crystal, 4 is laser light output from the solid-state laser medium 3, 32 is excitation light incident end face of the solid-state laser medium 3 and is non-reflecting to the excitation light 2, laser light 4 Is coated with total reflection. 33 is an end face of the solid-state laser medium 3 on which a coating that is non-reflective with respect to the laser light 4 is formed. 5 is a solid-state laser medium 3
The partial reflection mirror is arranged so as to face the end face 33.

Next, the operation will be described. The excitation light 2 enters from the excitation light incident end face 32 of the solid-state laser medium 3.
Repeated internal reflection on the upper and lower surfaces 31 of the solid-state laser medium 3,
The solid-state laser medium 3 is absorbed while being confined in the solid-state laser medium 3 and effectively excites the solid-state laser medium 3. By reflecting the light that spreads in the vertical direction with respect to the semiconductor laser active layer on the upper and lower surfaces 31, the photoexcitation region in the solid-state laser medium 3 becomes 0.
It will be about 5 mm. The excitation light incident end face 32 and the partial reflection mirror 5 constitute a stable laser resonator. For example, the excitation light incident end face 32 is a plane, and the radius of curvature of the partial reflection mirror 5 is 1.
Laser beam 4 with a fundamental mode (Gauss mode) diameter of about 0.35 mm when the resonator length is 000 mm and the cavity length is 10 mm.
Oscillates.

[0004]

In the conventional semiconductor pumped solid-state laser, a single laser beam 4 is emitted from a single device.
However, there is a problem that a plurality of devices must be prepared to obtain a plurality of independent laser beams.

The present invention has been made to solve the above problems, and an object thereof is to obtain a semiconductor pumped solid-state laser capable of generating a plurality of laser beams with a single device.

[0006]

According to a first aspect of the present invention, there is provided a semiconductor pumped solid state laser in which a plurality of microlenses for emitting a plurality of laser beams are arranged in a laser resonator.

According to a second aspect of the present invention, there is provided a semiconductor pumped solid-state laser in which a microlens for emitting a plurality of laser beams and a nonlinear optical element for wavelength conversion are arranged in a laser resonator. ..

A semiconductor pumped solid-state laser according to a third aspect of the present invention has a two-dimensional array of microlenses for emitting a plurality of laser beams in a laser resonator.

[0009]

[Operation] In the present invention, the excitation light from the semiconductor laser is incident on the solid-state laser medium, and a plurality of microlenses forms the same number of laser beams as the number of microlenses in one solid-state laser medium.

[0010]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings. Figure 1
In (a), 11 and 12 are semiconductor lasers that generate a plurality of excitation lights, for example, 10 at a pitch of 1 mm.
And 9 light emitting points are arranged on a straight line. 2 is excitation light, 3 is a solid-state laser medium, for example, Nd: YAG (Y with a rectangular cross section having a length of 10 mm, a width of 5 mm, and a thickness of 0.4 mm.
_3-x Nd _x Al ₅ O ₁₂ ) crystal, 41, 42, 43, 44 are laser beams output from the solid-state laser medium 3, 32 is one end face of the solid-state laser medium 3, and laser beams 41, 42, 4
A total reflection coating is formed on 3,44. The other end face 33 of the solid-state laser medium 3 is a laser beam 4
Non-reflective coatings are formed on 1, 42, 43 and 44. Reference numeral 34 denotes a side surface of the solid-state laser medium 3, on which a coating that is non-reflective with respect to the excitation light 2 is formed. Reference numeral 5 is a partial reflection mirror, and reference numerals 61, 62, 63 and 64 are microlenses interposed between the solid-state laser medium 3 and the partial reflection mirror 5 to make the shapes of the laser beams 41, 42, 43 and 44 constant.

Next, the operation will be described. The pumping light 2 generated from the semiconductor lasers 11 and 12 enters from the side surface 34 of the solid-state laser medium 3 and is repeatedly internally reflected by the upper and lower surfaces 31 of the solid-state laser medium 3 as shown in FIG. The solid-state laser medium 3 is effectively excited by being absorbed while being confined in the laser diode 3. Solid-state laser medium end face 32
A stable laser resonator is formed between the partial reflection mirror 5 and the partial reflection mirror 5, but four independent lenses each having an excitation area of about 0.5 mm × 0.5 mm by the action of the microlenses 61, 62, 63, 64. Laser resonator is constructed. For example, when the solid-state laser medium end face 32 and the partial reflection mirror 5 are both flat, and the focal lengths of the microlenses 61, 62, 63, 64 are 700 mm and the cavity length is 15 mm, the fundamental mode laser light diameter is about 0.35 mm. Four laser lights oscillate.

In the above embodiments, the microlenses having different focal lengths can be used for the focal lengths of the microlenses, and in this case, it is possible to oscillate laser lights having different laser light parameters. is there.

In the above embodiment, the number of light emitting points of the semiconductor lasers 11 and 12 is 10 or 9, and the microlens 6 is used.
1, 62, 63, 64 and laser beams 41, 42, 4
Although the number of 3, 44 is four, the number of light emitting points and the number of laser beams may be increased or decreased as necessary.

Although a plurality of microlenses 61, 62, 63 and 64 are used in the above embodiment, one-dimensional flat plate microlenses may be used, in which case the position of the microlenses can be easily set. There is.

Further, in the above embodiment, the microlens 6 is used.
1, 62, 63 and 64 form a stable laser resonator, but the stable laser resonator is formed by forming a concave surface of a number that locally oscillates in the partial reflection mirror without using a microlens. It is also possible to achieve the same effect as the above embodiment.

Example 2. FIG. 2 shows semiconductor lasers 1 to 4.
The individual pumping lights 21, 22, 23, and 24 are applied to the solid-state laser medium 3
Of the laser light 41, 42, which is incident from the end face 32 of the
This is an embodiment in which 43, 44, 45, 46, 47 are oscillated. In this embodiment, the laser lights 41, 43, 45 and 47 are excited only by the pump lights 21, 22, 23 and 24, respectively, and the laser lights 42, 44 and 46 are respectively excited by the pump light 2.
It is excited by two excitation lights 1 and 22, 22 and 23, and 23 and 24. Also here, the number of light emitting points of the semiconductor laser 1 and the number of laser beams can be freely set.

Embodiment 3. In the above embodiments, an example in which a plurality of laser beams having the same wavelength are obtained has been shown, but it is also possible to obtain laser beams having different wavelengths in each laser resonator. Figure 3946nm, 1.064μm, 1.319μ
a non-linear optical element 71 for oscillating a fundamental wave of three wavelengths of m and for converting three wavelengths installed in the laser resonator,
The second harmonic is generated by 72 and 73, and the second harmonic is generated (blue
m), green (532 nm), and red (660 nm). Both ends of the nonlinear optical element 71 are antireflection coated for 946 nm, both ends of 72 are antireflection coated for 1.064 μm, and both ends of 73 are antireflection coated for 1.319 μm. At 473 nm and 532n by the non-linear optical elements 71, 72 and 73 in which the fundamental waves of the respective wavelengths selectively oscillate and the phases are matched to the respective wavelengths.
The wavelengths of the laser beams 41, 42, and 43 of m and 660 nm are converted, and the selective reflection coating applied to the partial reflection mirror 5 efficiently extracts the laser beams to the outside of the laser resonator.

Example 4. In the above-described embodiments, an example in which a plurality of laser beams are obtained on a straight line has been shown. However, as shown in FIG. 4, a two-dimensional array laser beam can be obtained by using a two-dimensional array flat plate microlens or the like. You can Referring to FIG. 4, 1 is a semiconductor laser having four light emitting points, 21 and 2.
Reference numerals 2, 23, and 24 denote four pump lights generated from the semiconductor laser 1, 3 denotes a solid laser medium having a rectangular parallelepiped shape having a square cross section, 32 denotes a pump light incident end surface of the solid laser medium 3, and the pump light 21 , 22, 23, 24 are non-reflective, and the laser beam 4 is totally reflected.
Reference numeral 4 denotes 16 laser beams generated by the present laser, 5 denotes a partial reflection mirror, 6 denotes a microlens array such as a flat plate microlens having 16 lens components corresponding to the laser beam 4, and the solid laser medium 3 Sixteen laser resonators are configured with the excitation light incident end face 32 and the partial reflection mirror.

Since the semiconductor laser generally has a larger opening angle in the direction perpendicular to the active layer than in the horizontal direction, when the light emitting points are arranged in a line in the horizontal direction as shown in FIG. 4, the respective light emitting points are excited. There are multiple regions in the vertical direction (4 in the figure).
This is the range in which the aligned laser beams can be sufficiently excited. Therefore, according to this configuration, a two-dimensional array semiconductor edge-pumped solid-state laser can be easily obtained. Further, by performing intracavity wavelength conversion using a non-linear optical element, for example, a two-dimensional array green laser can be obtained.

[0020]

As described above, according to the semiconductor pumped solid-state laser of the present invention, the pumping light from the semiconductor laser is made incident on the solid-state laser medium, and a plurality of microlenses are used to form the microlens in one solid-state laser medium. Since the same number of laser beams as the number of laser beams are formed, it is possible to easily obtain a plurality of pumped solid-state lasers with a compact shape by using a single solid-state laser medium.

By using a two-dimensional array microlens, a two-dimensional array laser light can be obtained.

[Brief description of drawings]

1A is a plan configuration diagram showing a semiconductor pumped solid state laser according to an embodiment of the present invention, and FIG. 1B is a side view seen from a point A in FIG. 1A.

FIG. 2 is a plan configuration diagram showing another embodiment of the present invention.

FIG. 3 is a plan configuration diagram showing a third embodiment of the present invention.

4A is a plan configuration diagram showing a fourth embodiment of the present invention, and FIG. 4B is a side view of FIG. 4A.

5A is a plan view showing an example of a conventional semiconductor pumped solid-state laser, and FIG. 5B is a side sectional view of FIG. 5A.

[Explanation of symbols]

 11, 12 Semiconductor laser 2 Excitation light 3 Solid laser medium 5 Partial reflection mirror 32 End face of solid laser medium 33 End face of solid laser medium 34 Side face of solid laser medium 41, 42, 43, 44 Laser light 61, 62, 63, 64 Micro lens

Claims (3)

[Claims] 1. A semiconductor laser for generating pumping light, a solid-state laser medium confining the pumping light inside by internal reflection on a surface and pumped by the pumping light, and a pair facing each other with the solid-state laser medium interposed therebetween. A semiconductor pumped solid-state laser having a laser resonator having a reflecting mirror for emitting a laser beam, wherein a plurality of microlenses for emitting a plurality of the laser beams are provided in the laser resonator. A semiconductor-pumped solid-state laser characterized by: 2. A semiconductor laser that generates pumping light, a solid-state laser medium that confines the pumping light inside due to internal reflection on the surface, and is pumped by the pumping light, and a pair that face each other with the solid-state laser medium interposed therebetween. In a semiconductor pumped solid-state laser having a laser resonator having a reflecting mirror for emitting a laser beam, a plurality of microlenses for emitting a plurality of the laser beams and wavelength conversion are performed in the laser resonator. A semiconductor-pumped solid-state laser characterized in that nonlinear optical elements are respectively provided. 3. A laser resonance having a semiconductor laser for generating pumping light, a solid-state laser medium pumped by the pumping light, and a pair of reflecting mirrors facing each other with the solid-state laser medium interposed therebetween to emit laser light. In a semiconductor-pumped solid-state laser including a laser, a plurality of two-dimensional array-shaped microlenses for emitting a plurality of the laser lights are provided in the laser resonator, and the two-dimensional array-shaped laser light is A semiconductor-pumped solid-state laser characterized by being generated.