JPS61278824A - Optical synthesizing device - Google Patents

Abstract

PURPOSE:To adjust an optical path extremely accurately and easily and to reduce the size and cost of a device by using an AO element array to adjust the optical pathes of plural optical beams, and synthesizing the beams. CONSTITUTION:Optical beams emitted from three light sources are adjusted at their optical pathes so as to be parallel and synthesized. The 1st light source 30a is driven by a light source driving circuit 32 and the optical path of an optical beam 16a emitted from the 1st light source 30a is adjusted by driving the 1st AO elements 4a, 4a' part by an AO element array driving circuit 34. The position of the adjusted optical beam 16a is branched by a half mirror 36 and detected by an optical beam position detector 40 and a position signal outputted from a position signal detecting circuit 42 is compared with a reference position signal outputted from a reference signal output circuit 44 by a comparator 46. When both the position signals coincide with each other, the optical path of the 2nd light source 16b is adjusted and then the optical path of the 3rd optical beam 16c is also adjusted. Thus, the three optical beams 16a-16c are synthesized extremely accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to an optical multiplexing device that adjusts optical paths and multiplexes a plurality of light beams emitted from a plurality of light sources.

More specifically, the present invention relates to an optical multiplexing device that adjusts the optical path of a plurality of light beams and multiplexes them using an acousto-optic element array.

(Technical Background of the Invention and Prior Art) In recent years, technology for creating a high-power light beam by combining (synthesizing) multiple light beams respectively emitted from multiple light sources has been developed. It is required in various technical fields.

For example, if the light beam is
(Optical scanning that scans a recording medium by deflecting it with an optical deflector and reading various information such as image information recorded on the recording medium1, or recording various information on the recording medium. In the field, there is a demand for scanning with a light beam of higher power in order to speed up reading and recording.

One way to obtain such a high-power light beam is to prepare multiple light sources, adjust the optical paths of the multiple light beams emitted from them, collect them, and combine them to produce high-power light. Methods of creating beams are known.

Note that the multiplexing of light beams herein includes not only the case where a plurality of light beams are superimposed to form a single light beam or the light beams are focused on the same spot, but also the case where the light beams are made parallel to each other. If multiple beams are parallel to each other, they can later be focused on the same spot using a condenser lens, or if they are adjacent to each other and parallel, they can be condensed into a single beam. This is because it can be treated as a light beam.

In order to combine multiple light beams as described above, it is usually necessary to adjust the optical paths of the multiple light beams to make them parallel or to focus them on a predetermined spot, and such optical path adjustment is required. Conventionally, this has been accomplished by mechanically moving or rotating a light source, or by mechanically moving or rotating a mirror or lens.

However, when attempting to combine multiple light beams with high precision, the optical path adjustment of the light beams must be performed at an extremely high precision, for example, when multiplexing is performed by rotating the light source or mirror, etc. It is necessary to rotate with a high accuracy of radians, and such high-precision adjustment is extremely difficult with mechanical adjustment methods that change the angle of the light beam by mechanically moving moving parts such as the light source and mirror. be.

Therefore, as a result of various studies on methods that can easily and accurately adjust the optical path of a light beam, the inventors of the present invention found that using an acousto-optic element (hereinafter referred to as an AO element), for example, an acousto-optic deflector. Invented a method to adjust the optical path. This adjustment method electrically changes the optical path of the light beam using the acousto-optic effect, and does not involve mechanical movement of movable parts as in conventional mechanical adjustment methods, so it is possible to adjust the optical path with extremely high precision. This is extremely easy to do.

However, when trying to perform optical multiplexing using this method, for example, when combining 0 light beams, n AO elements are required, or when adjusting the optical path two-dimensionally as described later, 20
If the number of light beams to be combined is large, a corresponding number of AO elements must be prepared, and if a large number of currently available commercially available AO elements are prepared, In addition to being expensive, a large number of AO elements must be spatially arranged especially during multiplexing, which causes space problems such as increasing the size of the multiplexing device.

(Object of the Invention) In view of the above-mentioned circumstances, an object of the present invention is to provide an optical multiplexing system that can perform optical path adjustment with extremely high precision and ease during optical multiplexing, and that can reduce the size and cost of the device. The goal is to provide equipment.

(Structure of the Invention) In order to achieve the above object, the optical multiplexing device according to the present invention has the following features:
an AO element array in which a plurality of AO elements are arranged close to each other and are connected to each other to be integrated;
and an AO element array drive circuit that independently drives and controls each A○ element of the AO element array, and the AO element array is configured such that the light beams passing through each AO element are combined by the AO element drive circuit. That is, they are characterized in that they are driven to be parallel to each other or to be focused on the same spot, for example.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a conceptual diagram showing one embodiment of an optical multiplexing device according to the present invention. As shown in the figure, the optical multiplexing device according to the present invention utilizes an AO element array 2 formed by arranging a plurality of AO elements close to each other and interconnecting them to integrate them. The element array will be explained.

The AO element array according to the present invention is formed by arranging a plurality of AO elements close to each other and connecting them to each other to form an integrated unit. The AO elements may be connected in any manner, such as by connecting them through a material or by simply bringing them into contact with each other using an appropriate connecting means, and each AO element may be arranged in a straight line or in a curved manner. It may be any arrangement, such as a two-dimensional arrangement or a three-dimensional arrangement.

Each specific example of the AO element array shown in FIGS. 2 to 10 will be described below, but of course the AO element array that can be used in the present invention is not limited to the specific examples shown.

FIGS. 2 to 10 each show a specific example of an A* element array.

FIG. 2(a) is a perspective view, and FIG. 2(b) is a front view seen from the direction of arrow B in FIG. 2(a). The illustrated AO element array has three AO elements 4 arranged and connected in the direction of ultrasound propagation (the unsigned arrow in the figure indicates the direction of ultrasound propagation; the same applies to Figs. 3 to 10). It is made up of an integrated system.

Each AO element 4 consists of an acousto-optic element crystal (an optical crystal that constitutes an AO element, hereinafter simply referred to as an optical crystal) 10 and a transducer 12 attached to the crystal 10. Ultrasonic waves are applied to the optical crystals 10 from the transducer 12, and the ultrasonic waves travel in the Z direction within each optical crystal 10, and a light beam in the X direction is incident at right angles to the traveling direction of the ultrasound waves. 16 is appropriately deflected in two directions within the X-Z plane by each AO element 4, and the deflection angle changes according to the ultrasonic frequency that changes depending on the voltage applied to the transducer 12. The AO element is generally called an acousto-optic deflector.

In this embodiment, the sound absorbing material 18 is placed between each AO element 4.
The sound absorbing material 18 may be provided as necessary, and as described below, a spacer or a space etc. may be interposed between the sound absorbing material 18 and each AO. The elements may be glued together. In short, it is only necessary to decide whether or not to interpose something in between for adhesion, and if so, what to interpose therein, as appropriate and necessary. Regarding this point, the same applies to the specific examples described below.

FIG. 3 is a perspective view, and the illustrated AO element array is
The O elements 4 are arranged in a direction (two directions) perpendicular to the direction in which the ultrasonic waves travel (X direction), and are bonded and connected with a sound absorbing material 18 interposed between them. , the incident light beam in the X direction is appropriately deflected in the X direction within the X-y plane.

The specific examples shown in FIGS. 2 and 3 above are both linear AO element arrays in which three AO elements are arranged linearly, but the number of AO elements constituting the array in this case may be adjusted as appropriate. All you have to do is decide. In addition, as an AO element array,
The AO elements are not limited to being simply arranged linearly, but may be arranged planarly. That is, for example, a planar AO element such as one in which three AO element arrays shown in FIG. 2 or FIG. It may be an array.

The AO element array shown in FIGS. 2 and 3 directs the light beam one-dimensionally, in the case of FIG.
In the case shown in the figure, the light beam cannot be deflected (only in the X direction), but in the specific example shown in FIG. 4, the light beam can be deflected two-dimensionally (in the X direction and two directions),
Two AO elements 4 are arranged and directly bonded in the direction of the light beam 16 (X direction), stacked in three stages in two directions and bonded with sound absorbing material 18 in between, and arranged in the X direction. The two AO elements 4 are combined so that the propagation directions of the ultrasonic waves applied to the optical crystal 10 are orthogonal to each other (the X direction and two directions). Therefore, 3
The incident light beam 1G in the X direction of the book is suitably deflected in the X direction at each front AO element (on the delayed side in the traveling direction of the light beam 16), and then at the rear AO element (on the delayed side in the traveling direction of the light beam 16).
is deflected in two directions at the forward direction of travel),
It is possible to deflect the light beam two-dimensionally.

In addition, a three-dimensional AO element array is constructed in which a plurality of the specific examples shown in FIG. 4, for example three, are glued together in the X direction with a sound absorbing material in between, and a total of 18 AO elements are three-dimensionally connected. You can also. In this case, nine light beams can be deflected two-dimensionally.

In the specific example shown in FIG. 5, two transducers 12, 22 are attached to one optical crystal 10 at right angles, and both the ultrasonic waves in the X direction and the ultrasonic waves in the two directions travel within the same optical crystal 10. Three AO elements 4 configured in this manner are bonded together in the Z direction with a sound absorbing material 18 interposed between them, and one AO element 4 forms the front AO element shown in FIG. It has the functions of both a rear AO element and a rear AO element. Also in this specific example, it is possible to two-dimensionally deflect the light beam 16 in the X direction.

The above is an example of an AO single array array constructed by connecting a plurality of individually existing AO elements, but next is a specific example of an AO element array constructed by attaching a plurality of transducers to one optical crystal. I will explain about it.

6(a) is a perspective view, and FIGS. 6(b) and 6(c) are a front view and a right side view respectively seen from the direction of arrow B and the direction of arrow C in FIG. 6(a). In the example Z
Three transducers 12 are embedded and attached to one elongated optical crystal 10 extending in the direction,
Each transducer 12 constitutes one AO element 4 part together with a part of the optical crystal 10, and these AO element parts are connected via the optical crystal 10 and are integrated. In this specific example, the four AO elements are arranged in two directions, the ultrasonic waves also travel in two directions, and the incident light beam 16 in the X direction is deflected in two directions within the X-Z plane. This corresponds to the specific example shown in FIG. Note that 18 is a sound absorbing material, and 20 is a spacer or space.

In the specific example shown in FIG. 7, a transducer 72 is externally attached to the optical crystal 10, and the 4 parts of the AO element, which are each transducer 12 and a part of the optical crystal 10, are arranged in two directions. The traveling direction of the ultrasonic wave is the X direction, and the incident light beam 16 in the X direction is deflected in the X direction within the xy plane. This corresponds to the specific example shown in FIG.

The specific example shown in FIG. 8 is a planar AO element array, such as a combination of three AO element arrays shown in FIG. It is constructed by being buried.

The deflection of the incident light beam 16 and the numbers 18, 20 are the same as in FIG. In addition, Fig. 8(b) is shown in Fig. 8<
It is a right side view seen from the arrow B direction of a).

9(a) is a front view, and FIG. 9(b) is a right side view seen from the direction of arrow B in FIG. 9(a). This specific example can deflect the incident light beam 16 in the X direction two-dimensionally (X direction and two directions), and uses one flat optical crystal as in the specific example shown in FIG. Nine transducers 12 are embedded in the transducer 10 to form four parts of nine front A○ elements arranged on the y-z plane (this number 4 is not shown in FIG. 9). , Furthermore, there is another A at the rear of each of the four front AO elements (on the advancing side of the light beam 16 in the traveling direction).
The nine transducers 22 constituting such a tangential AO element part are arranged in such a way that the front AO element part, which is an O element part, is a rear AO element part whose ultrasonic propagation directions are orthogonal to each other. is embedded in the optical crystal 10. According to this specific example, first, the front A
○ Ultrasonic waves are propagated in two directions by the transducer 12 in the element portion, and accordingly, the light beam 16 is appropriately deflected in two directions in the AO element portion, and then the ultrasonic waves are propagated in the X direction by the transducer 22. The light beam 16 is appropriately deflected in the X direction at the rear AO element portion where the
Dimensional optical path adjustment is performed.

In the specific example shown in FIG. 4, a transducer 12 for deflecting one light beam 16 in two directions and a transducer 22 for deflecting it in the X direction are used (in the traveling direction of the light beam (X direction)). The optical crystal portions are embedded in the front and back, and the optical crystal portions through which the ultrasonic waves applied by the transducer 12 travel and the optical crystal portions through which the ultrasound waves applied by the transducer 22 travel are configured to be different. For example, as shown in FIG. 10, which is a right side view similar to FIG. 9(b), both transducers 12 and 22 are
It is also possible to embed the transducers 12 and 12 at the same location without dividing them into front and rear sections in the direction, so that the ultrasonic waves applied by both transducers 12 and 22 travel within the same optical crystal section.

Each transducer in each of the specific examples described above is connected to an AO element array drive circuit, and is configured to be able to apply voltage and control the applied voltage separately and independently.

Further, in any of the above-mentioned specific examples, another specific example may be constructed in which a plurality of specific examples, for example, two, are superimposed in the traveling direction of the light beam 16. This is convenient because the light beam 16 can be deflected twice in the same direction (for example, in two directions in the case of the specific example shown in FIG. 2), and the deflection angle can be increased.

Next, an embodiment of the optical multiplexing device according to the present invention using the AO element array configured as described above will be described with reference to FIG.

The multiplexing device shown in the figure adjusts and multiplexes the light beams emitted from three light sources so that their optical paths become parallel, and includes three light sources and an AO element as an optical path adjustment device. It is composed of an array and AO element array drive circuit, and a control section.

The three light sources 30a, 30b, and 30c are composed of semiconductor lasers, and are arranged so that their respective light beams (laser beams) 16a, 16b, and 16c are incident on the AO element array substantially in parallel, and are each driven by a light source drive circuit 32. Driven.
1 each light beam t6a, t6b, 16c
are incident on the AO element array 2 through a collimator lens (not shown) and further through a mirror (light beams 16b and 16c only), and the optical path is adjusted by the AO element array 2, and the beams are made parallel to each other and combined. be waved. The illustrated AO element array 2 shown in FIG. 4 is used.

The optical path adjustment of each light beam is performed as follows.

First, the first light source 30a is driven by the light source drive circuit 32, and the first AO element 4a adjusts the optical path of the light beam 16a emitted from the first light source 30a.
4a is driven by the AO element array drive circuit 34, and the first light beam 16a is directed to the first ΔO element 4a.
The optical path is appropriately adjusted in the y direction by the portion of the first AO element 4a, and the optical path is appropriately adjusted in two directions by a portion of the first AO element 4a, and the position of the adjusted optical beam 16a is split by a half mirror 36 and a condenser lens. Light beam 1 directed through 38 onto light beam position detector 40
6a, the light beam position detector 40 detects the device signal and the reference position signal output from the reference signal output circuit 44 is compared by the comparison circuit 46. However, if the two signals do not match, a control signal is output from the AO element drive control circuit 48 to the AO element array drive circuit 34 to adjust the optical path in the direction in which they match, and the drive circuit 34 outputs a control signal to the AO element array drive circuit 34.
Elements 4a and a portion of 4a are each independently controlled.

When the optical path of the first light beam 16a is adjusted appropriately and the two position signals match, the AO element/light source drive switching circuit 50 switches the second light source 30b and the second AO element 4.
b, a portion of 4b is driven, and the first light beam 1
The optical path of the second light beam 16b is adjusted in the same manner as in 6a, and then the optical path of the third light beam 16c is adjusted in the same manner, and these three light beams 16a, 1
6b and 16c are combined with extremely high precision through the above-mentioned optical path adjustments.

Note that how to adjust the optical path of each light beam is determined by what kind of reference position signal is outputted from the reference signal output circuit 44 for each light beam, and therefore the reference position signal is set appropriately. By doing so, arbitrary multiplexing modes can be performed.

The optical multiplexing device according to the present invention can be used not only for semiconductor lasers but also for multiplexing light beams emitted from various laser light sources or various other light sources, and can also be used for multiplexing light beams emitted from various laser light sources or other various light sources, and can also be used for multiplexing light beams emitted from various types of laser light sources or other various light sources, and can also be used for multiplexing light beams emitted from various laser light sources or other various light sources. The drive control of the array may be performed by any method, and is not limited to the method of driving by the control section described above.

Note that some types of phosphors are exposed to radiation (X-rays, α-rays, etc.).

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. 55-116340, No. 55-163472, No. 5
No. 6-11395, No. 9, No. 56-104645, etc.).

In this system, a stimulable phosphor sheet on which radiographic image information has been stored and recorded is scanned, the stimulable phosphor is stimulated to emit light, and excitation light of sufficient energy is applied to the stimulable phosphor to read the image information. It is necessary to irradiate the body.

The optical multiplexing device according to the present invention can be suitably used, for example, when multiplexing light beams emitted from a plurality of semiconductor lasers to create high-energy excitation light for reading such image information. It is something that can be done.

(Effects of the Invention) As explained above, the optical multiplexing device according to the present invention is configured to adjust the optical path of a plurality of light beams and multiplex them using an AO element array.

That is, the optical multiplexing device according to the present invention is configured to first perform optical path adjustment using an AO element. Since the adjustment is not performed by mechanically rotating the movable parts, it is possible to easily adjust the optical path with extremely high precision.

In addition, the optical multiplexing device according to the present invention is a novel and non-existent conventional device in which a plurality of AO elements are arranged close to each other and connected to each other to be integrated when adjusting the optical path of a plurality of light beams. Since this is done using an AO element array, the optical multiplexing device itself requires less time compared to simply obtaining multiple commercially available AO elements and arranging them spatially to configure the optical multiplexing device. It is possible to achieve miniaturization and cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing one embodiment of the optical multiplexing device according to the present invention, and FIGS. 2 to 10 are diagrams showing each specific example of an acousto-optic element array used in the optical multiplexing device according to the present invention. 2(a) is a perspective view, FIG. 2(b) is a front view, FIG. 3 is a perspective view, FIG. 4 is a perspective view, FIG. 5 is a perspective view, and FIG. 6(a) is a perspective view, FIG. 6(b) is a front view,
Figure 6 ((l is a right side view, Figure 7 is a perspective view, Figure 8 (a)
) is a front view, FIG. 8(b) is a right side view, FIG. 9(a) is a front view, FIG. 9(b) is a right side view, and FIG. 10 is a right side view. 2... Acousto-optic element array 4... Acousto-optic elements 16a, 16b, 16c -... Light beam 30
a, 30b, 30c...Light source 34...Acousto-optic element array drive circuit Fig. 1

Claims (1)

[Claims] In an optical multiplexing device that adjusts the optical paths and multiplexes a plurality of light beams emitted from a plurality of light sources, a plurality of acousto-optic elements are arranged close to each other and are connected to each other. and an acousto-optic element array drive circuit that independently drives and controls each acousto-optic element of the acousto-optic element array, the acousto-optic element array driving the plurality of light beams. An optical multiplexing device characterized in that it is configured to adjust the optical path of a beam.