JP2002100823A - Solid-state laser system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to easily perform the adjusting work of the tilt of mirrors and to simplify the structure of the support mechanical of the mirrors in a solid-state laser system of a structure that a solid-state laser oscillator, solid-state laser amplifiers and the mirrors are arranged within the same plane. SOLUTION: A solid-state laser system is constituted in a structure that the attitude of a solid-state laser oscillator 10 and solid-state laser amplifier 20 to a plane arranged with the oscillator 10, the amplifiers 20 and mirrors 30 are set in such a way that a laser beam is emitted from the oscillator 10 and the amplifiers 20 in the direction almost parallel to this plane and the mirrors 30 are turnably supported by only the surroundings of axes 2 almost vertical to this plane. In the assembly of a solid-state laser system and the maintenance of the laser system, the tilt of the mirrors 30 is adjusted only in the surroundings of the axes 2 conforming each mirror 30 with the positions of the oscillator 10 and each amplifier 20 within this plane.

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 system used as a light source of a liquid crystal projector, for example, and more particularly to a system capable of easily performing adjustment work during assembly and maintenance of the system.

[0002]

2. Description of the Related Art A liquid crystal projector that modulates light from a light source with a liquid crystal panel and projects the light on a screen has been widely used as a large-screen image display device. As a light source of the liquid crystal projector, a white light lamp such as a metal halide lamp or an ultra-high pressure mercury lamp is often used.

However, it is desirable to use a light source as close to a point light source as possible to further increase the brightness and contrast of the liquid crystal projector. For this reason, attempts have been made to use a laser device as a light source.

[0004]

For example, when a solid-state laser device is used as a light source of a liquid crystal projector, in order to obtain a laser beam having a sufficient amplitude level, the amplitude of the laser beam emitted from the solid-state laser A method of sequentially amplifying with a laser amplifier is considered.

FIG. 6 shows an example of the configuration of a general solid-state laser oscillator. FIG. 6A is a view from above, and FIG. 6B is a view from the side of the laser medium 13 and the resonator in FIG. It is. A slab-shaped laser medium (for example, made of YVO4 or YAG) 13 provided in a resonator constituted by a mirror 11 and a partially transmitting mirror 12 is supplied from an excitation light source (for example, a laser diode or a flash lamp) 14. Is excited by the excitation light, laser oscillation of a constant frequency occurs between the mirror 11 and the partially transmitting mirror 12, and the laser light transmitted through the partially transmitting mirror 12 is emitted from the solid-state laser oscillator 10 to the outside.

The laser medium 13 has a shape in which two end faces (laser light input / output faces) 13a and 13b are not parallel to each other. This is because, when the end faces 13a and 13b are made parallel to each other, laser oscillation (parasitic oscillation) having a frequency different from that generated between the mirror 11 and the partially transmitting mirror 12 occurs between the end faces 13a and 13b. This is to prevent such parasitic oscillation. The laser medium 13 has a trapezoidal side surface 13.
c and 13d in the vertical direction (ie, this side 13
c and 13d so that the excitation light from the excitation light source 14 is incident thereon.

Since the laser medium 13 has such a shape and orientation, the mirror 11 and the partially transmitting mirror 12 are connected to the end faces 13a and 13a of the laser medium 13, respectively.
The light refracted obliquely downward in (b) is disposed so as to be incident perpendicularly to the mirror surface. Therefore, laser light is emitted from the solid-state laser oscillator 10 obliquely downward.

FIG. 7 shows a configuration example of a general solid-state laser amplifier. FIG. 7A is a diagram viewed from the top, and FIG. 7B is a diagram viewed from the side of the laser medium 21 in FIG. The incident laser light passes through the inside of the laser medium 21, and the laser medium 21 is excited by the excitation light from the excitation light source 22, whereby the amplitude of the laser light is amplified. The laser medium 21 also has two end surfaces 21a and 21b that are not parallel to each other in order to prevent a decrease in amplification efficiency due to parasitic oscillation, and are provided with the trapezoidal side surfaces 21c and 21d oriented vertically. I have. Therefore, laser light is also emitted obliquely downward from the solid-state laser amplifier 20.

By the way, from the viewpoint of miniaturization of the liquid crystal projector, it is desirable to house these solid-state laser oscillators and solid-state laser amplifiers as compactly as possible in the housing of the liquid crystal projector. For this purpose, as shown in FIG. 8, the solid-state laser oscillator 10 and a plurality of (two in the figure) solid-state laser amplifiers 20 are arranged in parallel on the same plane (xy plane in the figure), and It is conceivable to assemble a solid-state laser system in which a plurality of mirrors 30 arranged in this plane reflect laser light emitted from the mirror and sequentially enter the solid-state laser amplifier 20 at the subsequent stage.

However, the solid-state laser oscillator 10 and the solid-state laser amplifier 20 are placed vertically as usual (as shown in FIG. 8, the trapezoidal side surfaces 13c and 13d of the laser medium 13 and the trapezoidal shape of the laser medium 21). Side 2 of
In the case where 1c and 21d are arranged in a posture perpendicular to this plane), laser light is emitted obliquely downward from this plane (a direction including the z-direction component in the figure). Therefore, at the time of assembling the solid-state laser system (at the time of manufacturing the liquid crystal projector) or at the time of maintenance after the manufacture of the liquid crystal projector, the position of the solid-state laser oscillator 10 and each solid-state laser amplifier 20 within this plane is adjusted. Not only must the tilt of each mirror 30 be adjusted about an axis in the vertical direction (z-direction in the figure), but also the laser light emitted obliquely downward is reflected in this plane so as to be reflected obliquely upward. The tilt of each mirror 30 must be adjusted about an axis in a parallel direction (x direction in the figure).

Thus, each mirror 30 around two axes
Adjusting the tilt of the camera takes a lot of trouble and time. In addition, in order to enable such an adjustment operation, each mirror 30 must be supported rotatably around these two axes, so that the structure of the support mechanism of the mirror 30 is complicated.

In view of the above, the present invention makes it possible to easily adjust the inclination of a mirror in a solid-state laser system in which such a solid-state laser oscillator, solid-state laser amplifier and mirror are arranged on the same plane. The object of the present invention is to simplify the structure of the mirror support mechanism.

[0013]

In order to solve this problem, the present applicant has developed a solid-state laser oscillator using a laser medium whose two end faces are not parallel to each other, a solid-state laser amplifier for amplifying an incident laser beam, and a solid-state laser amplifier. A mirror that reflects the laser light emitted from the solid-state laser oscillator and makes it incident on the solid-state laser amplifier is arranged in substantially the same plane, and the attitude of the solid-state laser oscillator with respect to this plane is substantially parallel to this plane from the solid-state laser oscillator. We propose a solid-state laser system set to emit laser light in the direction.

In this solid-state laser system, the attitude of the solid-state laser oscillator with respect to the plane on which the solid-state laser oscillator, the solid-state laser amplifier and the mirror are arranged is set so that laser light is emitted from the solid-state laser oscillator in a direction substantially parallel to this plane. Have been.

Therefore, unlike the case where laser light is emitted from the solid-state laser oscillator in an oblique direction with respect to this plane, during assembly or maintenance of the solid-state laser system, the laser light is reflected in this plane in an oblique direction. There is no need to adjust the tilt of the mirror around the parallel axis, only to align the solid-state laser oscillator and the solid-state laser amplifier within this plane, and only around the axis substantially perpendicular to this plane. It is enough to adjust the inclination of.

As described above, since it is sufficient to adjust the tilt of the mirror only around one axis, the operation of adjusting the tilt of the mirror can be easily performed. Further, in order to enable such an adjustment operation, it is sufficient to support the mirror so as to be rotatable only around this one axis, so that the structure of the mirror support mechanism is simplified.

When the solid-state laser amplifier also uses a laser medium whose two end faces are not parallel to each other,
It is preferable that the attitude of the solid-state laser amplifier with respect to this plane is also set such that laser light is emitted from the solid-state laser amplifier in a direction substantially parallel to this plane. Therefore, even when a plurality of solid-state laser amplifiers and a plurality of mirrors that reflect laser light emitted from a solid-state laser oscillator and sequentially enter the solid-state laser amplifiers are arranged, the work of adjusting the inclination of each mirror can be performed. This can be easily performed and the structure of the support mechanism of these mirrors can be simplified.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is applied to a light source of a liquid crystal projector will be described below. FIG. 1 shows a configuration example of a solid-state laser system according to the present invention, and portions common to those in FIGS. 6 to 8 are denoted by the same reference numerals. In the solid-state laser system 1, the solid-state laser oscillator 10 and the two solid-state laser amplifiers 20 are arranged in parallel on the same plane (xy plane in the figure).
A plurality of laser beams emitted from the solid-state laser oscillator 10 are reflected and sequentially incident on the subsequent solid-state laser amplifier 20, and the laser beams emitted from the final-stage solid-state laser amplifier 20 are reflected and emitted from the solid-state laser system 1 to the outside. Are arranged in this plane.

The solid-state laser oscillator 10 and the solid-state laser amplifier 20 are placed vertically (the trapezoidal side surfaces 13c and 13d of the laser medium 13 and the trapezoidal side surfaces 21c and 21d of the laser medium 21) in the usual manner. Rather than horizontal) (side 13c)
13d and the side surfaces 21c and 21d are arranged in a posture parallel to this plane).

Each mirror 30 is rotatably supported only by a support shaft 2 extending in a direction perpendicular to this plane (z direction in the figure).

The laser light emitted from the solid-state laser system 1 is condensed by a condensing lens 40 and a liquid crystal panel 41
And is modulated according to the voltage applied to the liquid crystal molecules of the liquid crystal panel 41. The light emitted from the liquid crystal panel 41 is emitted from the liquid crystal projector via a projection lens (not shown).
Projected to the screen.

The operation of adjusting the inclination of the mirror 30 at the time of assembling the solid-state laser system 1 (at the time of manufacturing a liquid crystal projector) or at the time of maintenance after manufacturing the liquid crystal projector is as follows.

Since the solid state laser oscillator 10 and the solid state laser amplifier 20 are arranged horizontally, the solid state laser oscillator 10 and the solid state laser amplifier 20
Laser light is emitted in a direction parallel to a plane on which the solid-state laser oscillator 10, the solid-state laser amplifier 20, and the mirror 30 are arranged.

Therefore, each mirror 30 is connected to the solid-state laser oscillator 10 and each solid-state laser amplifier 2 in this plane.
It is sufficient to adjust the tilt only around the support shaft 2, which is an axis perpendicular to this plane, in accordance with the position of 0.

As described above, the solid-state laser system 1
In this case, since it is sufficient to adjust the inclination of each mirror 30 only around one support shaft 2, the operation of adjusting the inclination of the mirror 30 can be easily performed.

Further, since each mirror 30 is rotatably supported only around one support shaft 2, the structure of the support mechanism of the mirror 30 is simplified.

Next, FIG. 2 shows another configuration example of the solid-state laser system according to the present invention, and FIGS. 3 and 4 show the configuration examples of the solid-state laser oscillator and the solid-state laser amplifier used in the solid-state laser system of FIG. 1 and FIG. 6 to FIG. 8 are denoted by the same reference numerals.

FIG. 3A is a diagram of the solid-state laser oscillator viewed from above, and FIG. 3B is a diagram of the laser medium 5 and the resonator of FIG. In the solid-state laser oscillator 4, the laser medium 5 having the same shape as the laser medium 13 in FIG. 6 has the trapezoidal side surfaces 5c and 5d directed sideways (that is, the excitation light from the excitation light source 14 Mirrors 11 and partially transmitting mirrors 12 so as to be incident on rectangular side faces 5e and 5f instead of 5c and 5d).
Are provided in the resonator constituted by

Since the laser medium 5 has such a shape and orientation, the mirror 11, the partially transmitting mirror 1
Numeral 2 is arranged so as to be inclined such that the light refracted obliquely in the lateral direction on the end faces 5a and 5b of the laser medium 5 is perpendicularly incident on the mirror surface. Therefore, the solid-state laser oscillator 4 emits laser light in an oblique horizontal direction.

FIG. 4A is a diagram of the solid-state laser amplifier viewed from above, and FIG. 4B is a diagram of the laser medium 7 of FIG. In this solid-state laser amplifier 6, the laser medium 7 having the same shape as the laser medium 21 in FIG.
Are provided with the trapezoidal side surfaces 7c and 7d directed sideways (that is, such that the excitation light from the excitation light source 22 enters the rectangular side surfaces 7e and 7f instead of the trapezoidal side surfaces 7c and 7d). ing. Therefore, laser light is also emitted from the solid-state laser amplifier 6 in an oblique horizontal direction.

As shown in FIG. 2, in the solid-state laser system 3, the solid-state laser oscillator 4 and the solid-state laser amplifier 6 are arranged vertically (the trapezoidal side surface 5c of the laser medium 5 in FIG. 3) in a usual manner. 5d and the trapezoidal side surfaces 7c and 7d of the laser medium 7 in FIG.

The operation of adjusting the inclination of the mirror 30 at the time of assembling or maintaining the solid-state laser system 3 is as follows.

The solid-state laser oscillator 4 and the solid-state laser amplifier 6 emit laser light obliquely in the horizontal direction, respectively, and the solid-state laser oscillator 4 and the solid-state laser amplifier 6 are arranged in a vertical arrangement as usual. Therefore, laser light is emitted from the solid-state laser oscillator 4 and the solid-state laser amplifier 6 in a direction parallel to this plane.

Therefore, it is only necessary to adjust the inclination of each mirror 30 around the support shaft 2 in accordance with the positions of the solid-state laser oscillator 4 and each solid-state laser amplifier 6 in this plane.

As described above, the solid-state laser system 3
However, since it is sufficient to adjust the inclination of each mirror 30 only around one support shaft 2, the operation of adjusting the inclination of the mirror 30 can be easily performed.

Further, since each mirror 30 is rotatably supported only about one support shaft 2, the structure of the support mechanism of the mirror 30 is simplified.

In the example of FIG. 1, the solid-state laser oscillator 1
0 and the solid-state laser amplifier 20 are placed horizontally,
A solid-state laser oscillator or a solid-state laser amplifier having a posture like that of the solid-state laser oscillator 10 or the solid-state laser amplifier 20 in FIG.

In each of the above examples, one solid-state laser oscillator and two solid-state laser amplifiers are arranged. However, one solid-state laser oscillator and one or three or more solid-state laser amplifiers are arranged. Of course, it is good.

In each of the above examples, the attitude of the solid-state laser oscillator and the solid-state laser amplifier with respect to the plane on which the solid-state laser oscillator, the solid-state laser amplifier and the mirror are arranged is changed from the solid-state laser oscillator and the solid-state laser amplifier to the plane parallel to this plane. It is set so that laser light is emitted in the direction. However, for example, one solid-state laser oscillator and one solid-state laser amplifier are arranged, and there is no mirror at the subsequent stage of the solid-state laser amplifier. In the case where the laser beam enters the illumination optical system), only the attitude of the solid-state laser oscillator with respect to this plane may be set so that laser light is emitted from the solid-state laser oscillator in a direction parallel to this plane.

In each of the above examples, the laser medium is 1
Although a solid-state laser oscillator and a solid-state laser amplifier having only one are used, a solid-state laser oscillator and a solid-state laser amplifier having two laser media may be used. FIG.
Is a side view of a portion of a laser medium and a resonator of a solid-state laser oscillator having two laser media, and two lasers arranged in a resonator constituted by a mirror 11 and a partially transmitting mirror 12 When the mediums 15 and 16 (having a shape similar to that of the laser medium 13 in FIG. 6) are each excited by excitation light from an excitation light source (not shown), laser oscillation occurs between the mirror 11 and the partially transmitting mirror 12. The laser light transmitted through the partial transmission mirror 12 is emitted from the solid-state laser oscillator to the outside.

In the above example, the present invention is applied to a light source of a liquid crystal projector. However, the present invention may be applied to a light source of a projector using a spatial light modulator other than a liquid crystal panel. The present invention may be applied to appropriate uses of the light source.

Further, the present invention is not limited to the above-described example, and it is needless to say that various other configurations can be adopted without departing from the gist of the present invention.

[0043]

As described above, according to the solid-state laser system according to the present invention, it is possible to adjust the inclination of the mirror that makes the laser light emitted from the solid-state laser oscillator incident on the solid-state laser amplifier only around one axis. As a result, the effect of easily adjusting the inclination of the mirror can be obtained.

Further, in order to enable such an adjustment operation, it is sufficient to support the mirror so as to be rotatable only around this one axis, so that the structure of the mirror support mechanism can be simplified. Can be

In addition, when the attitude of the solid-state laser amplifier with respect to this plane is set so that laser light is emitted from the solid-state laser amplifier in a direction substantially parallel to this plane, a plurality of solid-state laser amplifiers and a solid-state laser oscillator are provided. When a plurality of mirrors that reflect the laser light emitted from the mirror and sequentially enter these solid-state laser amplifiers are arranged in this plane, the work of adjusting the inclination of each mirror can be easily performed and the support mechanism of the mirror can be easily adjusted. An effect that the structure is simplified can be obtained.

[0046]

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a solid-state laser system according to the present invention.

FIG. 2 is a diagram showing another configuration example of the solid-state laser system according to the present invention.

3 is a diagram illustrating a configuration example of a solid-state laser oscillator used in the solid-state laser system of FIG. 2;

FIG. 4 is a diagram illustrating a configuration example of a solid-state laser amplifier used in the solid-state laser system of FIG. 2;

FIG. 5 is a diagram showing a portion of a laser medium and a resonator of a solid-state laser oscillator having two laser media.

FIG. 6 is a diagram illustrating a configuration example of a general solid-state laser oscillator.

FIG. 7 is a diagram illustrating a configuration example of a general solid-state laser amplifier.

8 is a diagram showing a configuration example of a solid-state laser system using the solid-state laser oscillator of FIG. 6 and the solid-state laser amplifier of FIG. 7;

[Explanation of symbols]

1,3 solid-state laser system, 11,30 mirror, 2 support axis, 4,10 solid-state laser oscillator, 5,7,13,15,16,21 laser medium, 5a, 5b, 7a, 7b, 13a, 13b, 21
a, 21b End face of laser medium, 5c, 5d, 7
c, 7d, 13c, 13d, 21c, 21d trapezoidal side surface of laser medium, 5e, 5f, 7e, 7f rectangular side surface of laser medium, 6,20 solid state laser amplifier, 12 partially transmitting mirror, 14,22 Excitation light source, 40 condenser lens, 41 liquid crystal panel

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 EA13 HA28 2H091 FA46Z LA09 5F072 AB01 AB20 AK03 JJ20 KK05 KK30 MM17 PP01 PP07 YY20

Claims (3)

[Claims] 1. A solid-state laser oscillator using a laser medium whose two end surfaces are not parallel to each other, a solid-state laser amplifier for amplifying an incident laser light, and a solid-state laser that reflects laser light emitted from the solid-state laser oscillator. A mirror to be incident on the amplifier is disposed in substantially the same plane, and the attitude of the solid-state laser oscillator with respect to the plane is set so that laser light is emitted from the solid-state laser oscillator in a direction substantially parallel to the plane. A solid-state laser system. 2. The solid-state laser system according to claim 1, wherein the mirror is supported rotatably only about an axis substantially perpendicular to the plane. 3. The solid-state laser system according to claim 1, wherein the solid-state laser amplifier uses a laser medium whose two end surfaces are not parallel to each other, and the posture of the solid-state laser amplifier with respect to the plane is the same. A solid-state laser system wherein a laser beam is emitted from a solid-state laser amplifier in a direction substantially parallel to the plane.