JPH0261611A - Laser light source device for multiplexing - Google Patents

Abstract

PURPOSE:To facilitate the adjustment and to improve the stability with time by composing a collimator optical system of 1st lens parts which are united with laser light sources previously as light source units and 2nd lens parts which are movable about the laser light sources. CONSTITUTION:This device consists of laser light sources 3A - 3J, the collimator optical systems composed of 1st lens parts 6A - 6J and 2nd lens parts 4A - 4J arranged in the optical paths of laser beams 3a - 3j, an optical path adjusting element 5 which projects the laser beams 3a - 3j on mutually close parallel optical paths, and a holding member 2 which supports them integrally. Then the positions of the 1st lens parts 6A - 6J are adjusted mutually and they are fitted to the holding member 2 as the light source units 10A - 10J; and the 2nd lens parts 4A - 4J are fitted to the holding member 2 while their positions are adjusted about the light source units 10A - 10J in a plane perpendicular to the optical axes from them. Therefore, the positions of the laser light sources 3A - 3J are adjusted only as to the 2nd lens parts 4A - 4J. Consequently, the assembly is facilitated and the stability with time is improved.

Description

Detailed Description of the Invention (Field of the Invention) The present invention relates to a full-wave laser capable of combining low-power laser beams emitted from laser light sources such as semiconductor lasers to obtain a high-power laser beam. The present invention relates to a light source device, and particularly relates to a white wave laser light source device that is easy to assemble.

(Prior Art) As is well known, optical scanning devices that scan a laser beam by deflecting it with an optical deflector are widely used in, for example, various scanning recording devices, scanning reading devices, etc. In scanning devices, for example, in order to speed up reading and recording, it is being considered to combine a plurality of laser beams and use them as scanning light. This multiplexing of laser beams is particularly required when the laser light source is a semiconductor laser. In other words, compared to gas lasers, semiconductor lasers are smaller, cheaper, consume less power, and can be directly modulated by changing the drive current.
Although it has many advantages, the current output is only 20 to 30,771 W when continuous oscillation is used, and therefore it is difficult to use a light beam scanning device that requires high-energy scanning light, such as recording materials with low sensitivity ( It is extremely difficult to use this method in a scanning recording device that records on a DRAM material such as a metal film 5 or an amorphous film.

Also, some types of phosphors are exposed to radiation (X-rays, α-rays.

When irradiated with beta rays, gamma rays, electron beams, ultraviolet rays, etc., some of this radiation energy is accumulated in the phosphor, and when this phosphor is irradiated with excitation light such as visible light, the accumulated energy It is known that stimulable phosphors exhibit stimulated luminescence, and by using such stimulable phosphors, radiation image information of subjects such as the human body can be transferred to stimulable phosphors that have a layer made of stimulable phosphors. This stimulable phosphor sheet is scanned with excitation light such as a laser beam to generate stimulated luminescent light, and the resulting stimulated luminescent light is read photoelectrically to obtain an image signal. The present applicant has already proposed a radiation image information recording and reproducing system that outputs a radiation image of a subject as a visible image to a recording material such as a photographic light-sensitive material, a CRT, etc. based on an image signal (Japanese Patent Laid-Open No. 12429/1989). , No. 55-118340, No. 55-183472, No. 5
No. 6-11395, No. 5B-104845, etc.).

In this system, an optical scanning device using a semiconductor laser is considered to be used to scan the stimulable phosphor sheet on which radiation image information is stored and read the image information. In order to read the sheet at high speed, it is necessary to irradiate the phosphor with sufficiently high-energy excitation light. Therefore, the optical scanning device using the semiconductor laser is used in this radiation image information recording and reproducing system. It is also extremely difficult to use.

Therefore, as mentioned above, in order to obtain a sufficiently high-energy scanning beam from a semiconductor laser etc. with low optical output, it is necessary to use multiple laser light sources and combine the laser beams emitted from these laser light sources into one beam. desirable.

In order to combine laser beams emitted from multiple laser light sources into a single laser beam as described above, the laser beams emitted from each laser light source are usually made into parallel beams using collimator lenses, and then placed close to each other. The laser beams are guided into parallel optical paths, and these laser beams are focused to the same focusing position by a focusing lens.

Additionally, the present applicant has already proposed a full-wave laser light source device equipped with a plurality of laser light sources, which makes it possible to efficiently combine the laser beams (Patent Application No. 83-35
No. 836, etc.). Such a light source device includes a collimator optical system that is arranged along with the plurality of laser light sources on the optical path of each laser beam emitted from the laser light source, and that converts each laser beam into a parallel beam, and a collimator optical system that is arranged on the optical path of the laser beam. and an optical path adjustment element that directs each laser beam into parallel optical paths close to each other and is integrally held by a holding member.If such a light source device is used, the laser beams will be emitted from the light source device. A plurality of laser beams can be focused on a single point at a desired position simply by making the laser beams enter the focusing lens. Note that the collimator optical system for each laser beam is composed of a plurality of lenses.

(Problem to be Solved by the Invention) By the way, in order to combine laser beams with high precision using the above-mentioned light source device, the laser beams emitted from the light source device should take predetermined optical paths parallel to each other, and each laser beam should be parallel to each other. It is necessary to correctly adjust the position of each lens of the collimator optical system in the light source device with respect to the laser light source so that the laser beam becomes a beam. However, when assembling the light source device, it is extremely troublesome to move and adjust each of the lenses relative to the holding member, and this greatly increases the time and effort required to assemble the device. There is this inconvenience. In addition, lenses whose positions are adjusted during assembly in this way tend to be misaligned when the environmental temperature changes, and there is a problem that they lack stability over time.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a full-wave laser light source device that is easy to assemble and has high stability over time.

(Means for Solving the Problems) A full-wave laser light source device of the present invention includes a plurality of laser light sources,
a collimator optical system including a first lens section and a second lens section disposed on the optical path of each laser beam emitted from the plurality of laser light sources; An optical path adjusting element that emits the beams into parallel optical paths close to each other, and a holding member that integrally supports the laser light source, the collimator optical system, and the optical path adjusting element, the laser light source and the laser light source. The respective first lens parts corresponding to the above are attached to the holding member as a light source unit by mutually adjusting the positions and being integrated, and the second lens parts are attached to the holding member and the light source unit. On the other hand, it is characterized in that the unit is mounted with its position adjusted within a plane perpendicular to the optical axis of the unit.

(Function) As mentioned above, the collimator optical system is connected to the first lens part and the second lens part.
If the first lens part is positioned in advance with respect to the laser light source and integrated as a light source unit,
The first lens part can be incorporated into the holding member without adjusting the position when assembling the device. Therefore, the position adjustment with respect to the laser light source only needs to be performed for the second lens portion, and work efficiency is greatly improved.

As mentioned above, the second lens section moves at least in a plane perpendicular to its tip axis, and the optical axis direction of the first lens section (i.e., the light source unit) and the second lens section If sufficient positional accuracy cannot be obtained only by the shape of the holding means, these may also be adjustable in the optical axis direction. In that case, moving the second lens part requires moving the lens part in a three-dimensional direction, which is not preferable because the moving means becomes expensive, and the light source unit must be moved in the direction of its optical axis. It is desirable to do so.

Furthermore, in this device, the first lens section, which is pre-assembled in the light source unit, is less likely to shift its position over time, so that the stability of the laser beam emission state over time can be improved.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a full-wave laser light source device according to an embodiment of the present invention.

In the illustrated full-wave laser light source device, each of the upper plates 2A of the holding member 2 includes a semiconductor laser 3A.

3B, 3C, 3D, 3E, 3F, 3G, 3H, 3L3J
and a convex lens 6A, which is the first lens portion.

6B, 6C, 6D, 6E, 6F, 6G, 6H, 61, 6
The light source unit IOA is formed by holding J in each lens barrel.
, IOB, IOc, IOD, IOE, IOF, 10GS
The IOH1101SIOJ are held in two rows, and the semiconductor lasers 3 are mounted in the upper plate 2A at the same position.
The laser emission axes of A to 3J are parallel to each other. Further, concave lenses 4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H, 4, which are second lens parts, are provided on the bottom surface of the upper plate 2A facing the light source units IOA to IOJ.
1.4J is fixed. Furthermore, a pair of mirror holding plates 2E are provided on the front and rear surfaces of the support column 2B, which is the central part of the holding member 2.
are attached to the mirror holding plate 2E, and a reflecting mirror 5 is mounted on the mirror holding plate 2E, facing each of the concave lenses 4A to 4J.
is installed. In addition, the above light source unit IOA
~10J1 The concave lenses 4A to 4J and the reflective mirror 5 are arranged symmetrically with respect to the support column 2B. Furthermore, a first side plate 2C is attached to one side of the support 2B, and a second side plate 2D that supports a polarizing beam splitter, a 1/2 wavelength plate, etc., which will be described later, is attached to the other side. The holding member 2 includes the upper plate 2A and the support column 2.
B1 first and second side plates 2C, 2D, mirror holding plate 2
E, and the bottom plate 2F attached to the lower end surface of the support column 2B.
It consists of The holding member 2 is made of novinite, kovar, invar, ceramic, or the like, which has a small coefficient of linear expansion.

As mentioned above, inside the light source units IOA to IOJ,
Convex lenses 6A to 6J are disposed as first lens sections facing each of the semiconductor lasers 3A to 3J. ), in this device, the concave lenses 4A to 4J and these convex lenses 6A to 6 are shown.
J constitutes a collimator optical system. As shown in FIG. 2, the laser beam 3a emitted from the semiconductor laser 3A becomes a parallel beam by passing through this collimator optical system, and the laser beams 3b to 3j emitted from the other semiconductor lasers 3B to 3J also become parallel beams. A collimator optical system placed on each optical path converts the beam into a parallel beam.

Laser beams 3a, 3c, 3e that have become parallel beams
.

3g and 31 are reflected by the reflecting mirror 5 disposed below and then incident on the polarized beam splitter. The light source units IOA, IOc, IOE.

Semiconductor lasers 3A, 3C, and 3E in LOGS101.

3G, 31 are laser beams 3a,
3c, 3es, 3g, and 31 are arranged so as to be emitted within the same plane, and each reflecting mirror 5 on the optical path of these laser beams is separated vertically by a mirror holding plate 2E with a step as shown in the figure. Since the laser beam is held with a gradual shift in the direction, the laser beam 3as3as Bes
The reflection positions by the reflecting mirrors 5 of 3g and 31 are slightly shifted only in the vertical direction, and the laser beam reflected by each reflecting mirror 5 is 38% Bes 3e, 3g, 31
take parallel optical paths very close to each other in the vertical direction. Moreover, on the back side of the pillar 2B, a semiconductor laser 3B
The laser beams 3b, 3d, 3f, 3h, and 3j emitted from , 3D, , 3F, 3H, and 3J are similarly reflected by the reflecting mirror 5 and take parallel optical paths very close to each other in the vertical direction. . Further, the heights of the laser beams (for example, laser beams 3a and 3b, laser beams 3c and 3d) emitted from semiconductor lasers disposed at opposing positions via the pillar 2B and reflected by the reflecting mirror 5 are equal to each other. Also, all light source units 10A
-10J is fixed to the upper plate 2A so that the polarization directions of the laser beams 3a to 3j reflected by the reflection mirror 5 are uniform (in the direction of arrow a in FIG. 1).

Note that laser beams 3a to 3j are provided on the second side plate 2D.
An opening is formed that allows the light to enter each element on the side plate.

The polarizing beam splitter 7 has a characteristic of reflecting light polarized in the direction of arrow a, and the polarizing beam splitter 7
a, 3c, 3es 3g, 31 are reflected by this polarizing beam splitter. On the other hand, laser beam 3b
, 3d, 3f', 3h, and 3j are reflected by mirror 8 to change the optical path by about 90'', and then pass through 172 wavelength plate 9.
By passing the light, the polarization direction is changed by 90 degrees, and the light becomes polarized in the direction indicated by the arrow. The polarizing beam splitter 7 transmits light polarized in the direction indicated by the arrow, and therefore the laser beams 3b and 3d
, 3f, 3h, and 8j pass through the polarizing beam splitter 7, and the laser beam 3b becomes the laser beam 3a, the laser beam 3d becomes the laser beam 3c, and the laser beam 3
r is emitted onto the same optical path as the laser beam 3e, the laser beam 3h and the laser beam 3g, and the laser beam 3j and the laser beam 31, respectively. In this way, ten laser beams 3a~ emitted to parallel optical paths in close proximity to each other.
The cross section of the beam 3j is shown in FIG.

By the way, when assembling the above-mentioned light source device, it is necessary to correctly determine the position of each optical element of the above-mentioned collimator optical system in order to emit a laser beam in a predetermined state. The convex lenses 6A to 6J, which are the first lens portions of the collimator optical system, are adjusted to take predetermined positions with respect to the semiconductor lasers 38 to 3J, and the light source units l
It is integrated with a semiconductor laser as 0A-10J,
The concave lenses 4A to 4J, which are one of the second lens parts, are movable two-dimensionally in a plane perpendicular to the optical axis when they are attached. ). That is, when assembling the light source device, first the light source units 10A-10J are inserted into the holes 2a (
(see Figure 2). Next, concave lenses 4A to 4J
The light source units IOA to I are located on the bottom of the upper plate 2A, respectively.
Each of the concave lenses 4A to 4
After each J is placed in a predetermined position, adhesive is injected between the support frame of the lens (the support frame 4a of the concave lens 4A is shown in FIG. 2) and the bottom of the two upper plates. The concave lenses 4A to 4J are fixed to the upper plate 2A.

Further, the position adjustment of the collimator optical system in the optical axis direction of the laser beam is performed by moving the positions of the light source units IOA to IOJ in the vertical direction as necessary. Note that the light source unit 10A-10J and the hole 2a of the upper plate 2A
The peripheral surface of the light source unit may be threaded so that the light source unit can be easily moved up and down. Also, as above,
Adjustment of the optical path and focus of the laser beams 3a to 3j by moving the concave lenses 4A to 4J and the light source units 10A to 10J is performed when the laser beams that are combined after passing through the polarizing beam splitter 7 pass through a focusing lens (not shown). This may be done by detecting whether or not the combined laser beam is focused on a predetermined position, but a half mirror may be placed on the optical path of the combined laser beam to extract a part of the laser beam as a monitor light. This may be carried out by focusing this monitor light and detecting with a position sensor whether or not the focusing position and focusing spot diameter are in a predetermined state.

As described above, according to the light source device of this embodiment, the convex lens that is the first lens portion is incorporated in the light source unit together with the semiconductor laser in advance, so there is no need to position it with respect to the semiconductor laser. The position of the optical element relative to the laser can be adjusted by moving only the concave lens, which is the second lens portion. Therefore, the position of the collimator optical system can be easily adjusted in a short time when assembling the device. Further, even if the environment such as the surrounding temperature changes, there is almost no change in the positional relationship between the first lens part and the semiconductor laser, so the stability of the laser beam emission state can be improved. Note that the position of the second lens part may be adjustable not only when assembling the apparatus, but also after assembling the apparatus so that changes in the position of the lens part over time can be corrected. Further, each of the first lens section and the second lens section may be composed of a plurality of lenses for the optical path of one laser beam. Further, it is preferable that the top plate 2A, support column 2B, side plates 2C, 2D, mirror holding plate 2E, and bottom plate 2F of the holding means 2, which support each optical element of the light source device, are partially or entirely integrally molded. If integral molding is performed, processing and assembly will be easier, and there will be no fear that the joints will shift in position due to changes over time, so it is possible to improve the accuracy of the multiplexing of the entire device.

(Effects of the Invention) As explained above, according to the full-wave laser light source device of the present invention, the collimator optical system is formed by combining the first lens portion, which is integrated in advance with the laser light source as a light source unit, and the laser light source. Since the second lens part is movable relative to the laser light source, adjustment is easier than when adjusting the position of all lenses in the collimator optical system relative to the laser light source, and stability over time is improved. be able to.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a full-wave laser light source device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line X-X in FIG. 1, and FIG. 3 is a diagram showing a laser beam emitted from the light source device. FIG. 3 is a schematic diagram showing a beam cross section. 2... Holding members 3A, 3B, 3C, 3D, 3E, 3F, 3G
. 3H, 31, 3J... Semiconductor laser 3a, 3bs 3cs 3ds 3es 3f',
3g, 3h, 31.3j...Laser beams 4A, 4B, 4C, 4D, 4E, 4F, 4G. 4H, 41, 4J...Concave lens 5...Reflection mirror 6A, 6B, 6C, 6D16E, 6F, 6G. 6H, 6I, 6J...Convex lens 7...Polarizing beam splitter 10ASIOB, 10°C, IOD, IOE, IOF,
LOG.

Claims (1)

[Claims] A collimator optical system including a plurality of laser light sources, a first lens section and a second lens section disposed on the optical path of each laser beam emitted from the plurality of laser light sources, and a collimator optical system disposed on the optical path of the laser beam. Each of the laser light sources includes an optical path adjustment element that is provided and emits each laser beam into a parallel optical path close to each other, and a holding member that integrally supports the laser light source, the collimator optical system, and the optical path adjustment element; The respective first lens portions corresponding to the laser light source are attached to the holding member as a light source unit by mutually adjusting their positions and being integrated, and the second lens portion is attached to the holding member as a light source unit. A full-wave laser light source device that is attached to a light source unit with its position adjusted within a plane perpendicular to the optical axis of the unit.