JP2005266523A - Light source unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the efficiency of incidence of laser light on an optical waveguide while shortening the time needed to assemble a light source unit as much as possible. <P>SOLUTION: The light source unit is equipped with a semiconductor laser element, an optical waveguide type 2nd harmonic generating element 41, and an optical fiber 36 which guides projection light of the semiconductor laser element to an optical waveguide of the 2nd higher harmonic generating element. The unit is also provided with a holding member 44 holding the optical fiber 36 while exposing the optical fiber 36 nearby the tip on the side of the 2nd higher harmonic generating element 41. The tip of the optical fiber 36 on the side of the 2nd higher harmonic generating element 41 is fixed to a light incidence end surface of the optical waveguide 41a with an optical adhesive GL1, and the holding member 44 is fixed to a base 42 with an adhesive GL2 having a faster setting speed than the optical adhesive GL1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides a light source device including a semiconductor laser element, an optical waveguide type second harmonic generation element, and an optical fiber that guides light emitted from the semiconductor laser element to the optical waveguide of the second harmonic generation element. About.

Such a light source device is a device that takes out light emitted from a semiconductor laser element into an optical waveguide of a second harmonic generation element and extracts a second harmonic having a wavelength half that of the incident laser light.
In such a light source device, the laser light emitted from the semiconductor laser element needs to be efficiently incident on the optical waveguide of the second harmonic generation element, and the emitted laser light from the semiconductor laser element is an optical system mainly composed of lenses. In addition to the configuration for condensing the light on the light incident end face of the optical waveguide, the configuration for guiding the emitted light of the semiconductor laser element to the optical waveguide of the second harmonic generation element with an optical fiber as described in Patent Document 1 below Is also considered.
Conventionally, the laser beam emitted from the semiconductor laser element is incident on the optical waveguide through an optical fiber. Conventionally, as described in Patent Document 1 below, the support member of the second harmonic generation element supports the vicinity of the tip of the optical fiber. It is considered that a V-shaped groove is formed to position the light emitting end of the optical fiber and the light incident end face of the optical waveguide.
JP 2003-218441 A

However, in the above-described conventional configuration, there is a variation in the formation position of the optical waveguide in the second harmonic generation element, and the incident efficiency of laser light into the optical waveguide is lowered depending on the mounting state of the second harmonic generation element. .
The present invention has been made in view of such circumstances, and its purpose is to improve the efficiency of laser light incident on the optical waveguide while reducing the time required for the assembly work of the light source device as much as possible. It is in the point to make.

  The first invention of the present application includes a semiconductor laser element, an optical waveguide type second harmonic generation element, and an optical fiber for guiding the emitted light of the semiconductor laser element to the optical waveguide of the second harmonic generation element. In the provided light source device, a holding member is provided to hold the vicinity of the tip of the optical fiber on the second harmonic generation element side with the tip exposed, and the second harmonic generation in the optical fiber. The tip on the element side is fixed to the light incident end face of the optical waveguide with an optical adhesive, and the holding member is fixed to the support base with an adhesive having a faster curing speed than the optical adhesive. Configured.

In other words, in order to maintain the position of the optical fiber with the tip of the optical fiber positioned relative to the optical waveguide of the second harmonic generation element, the holding member holds the vicinity of the tip of the optical fiber on the second harmonic generation element side. At the same time, the tip of the optical fiber is fixed to the light incident end face of the optical waveguide with an adhesive, and the holding member for holding the optical fiber is fixed to the support base with the adhesive.
As a result, the relative positional relationship between the holding member that holds the optical fiber and the support base thereof is adjusted so that the tip of the optical fiber has an appropriate positional relationship with respect to the light incident end face of the optical waveguide. After the adjustment, the tip of the optical fiber and the holding member are fixed with an adhesive, and the positional relationship after the adjustment can be maintained, and the incident efficiency of the laser light to the optical waveguide is improved as much as possible. , Can hold that state.

In addition, the time required for assembling the light source device can be reduced as much as possible in relation to the positioning of the tip of the optical fiber with respect to the optical waveguide of the second harmonic generation element as described above.
That is, the optical adhesive used when the optical fiber tip is bonded and fixed to the light incident end face of the optical waveguide should be one that has a sufficiently high transparency at the wavelength of the laser light and a small shrinkage during curing. Is required.
An optical adhesive having such characteristics often requires a relatively long time to cure, but if the optical fiber is fixed only at the tip of the optical fiber, the amount of adhesive used is very small. It takes less time to cure.

On the other hand, in order to fix the holding member that holds the optical fiber to the support base, it is necessary to secure a certain large contact area, and the amount of adhesive necessary for fixing is also compared with the fixing of the tip of the optical fiber. A large amount of adhesive is required.
Therefore, if the adhesive used for fixing the tip of the optical fiber is used for fixing the holding member, the curing time becomes long.
Therefore, the adhesive for fixing the holding member for holding the optical fiber to the support base is cured using an adhesive having a faster curing speed than the optical adhesive for fixing the tip of the optical fiber. Reduce time.
Such an adhesive having a fast curing speed tends to increase the shrinkage during curing, and there is a possibility that the position of the holding member may fluctuate during curing, but the position where the holding member is bonded and fixed is the tip of the optical fiber. Since it is somewhat apart from the fixing position of the optical fiber, it is easier to cope with curing shrinkage, such as applying an adhesive to the shaft object, compared to the fixing of the tip of the optical fiber, and an adhesive having a certain degree of curing shrinkage is used. Even if it is used, the influence of curing shrinkage can be sufficiently reduced.

  According to a second invention of the present application, in addition to the configuration of the first invention, the support base includes a holding member support portion that supports the holding member, and an SHG that supports the second harmonic generation element. An adhesive for fixing the holding member between the bonding position of the holding member and the mounting position of the second harmonic generation element and the optical fiber on the support base. There is provided a movement restricting portion for restricting the movement of the optical adhesive that fixes the tip of the optical adhesive.

That is, the second harmonic generation element is generally used by heating the second harmonic generation element to a constant temperature because the conversion characteristic of the second harmonic generation element depends on temperature.
Therefore, in consideration of a relative position variation due to thermal expansion, the holding member supporting portion that supports the holding member and the SHG supporting portion that supports the second harmonic generation element are integrally formed to hold the optical fiber. It is preferable to share a thermal environment by arranging the holding member and the second harmonic generation element on a common support base.
Furthermore, by processing and forming the support base as a single member, the relative positional relationship between the mounting position of the second harmonic generation element and the bonding position of the holding member can be set with high accuracy.

However, when the holding member support portion and the SHG support portion are integrally formed in this way, the bonding position of the holding member and the bonding position of the tip of the optical fiber are not so close, but are greatly separated. Therefore, when an adhesive is applied to both, the adhesive may flow and mix from one to the other, changing the properties of the adhesive. Such a change in the properties of the adhesive can cause a change in the optical properties of the adhesive or a positional variation during curing.
Therefore, movement of the adhesive that fixes the holding member and the optical adhesive that fixes the tip of the optical fiber between the bonding position of the holding member and the mounting position of the second harmonic generation element on the support base. A movement restricting portion for restricting the movement is provided.

In addition to the configuration of the second invention, the third invention of the present application is characterized in that the movement restricting portion is between the adhesion position of the holding member and the attachment position of the second harmonic generation element. It is configured by forming a groove.
That is, with respect to providing a movement restricting portion for restricting the movement of the adhesive fixing the holding member and the optical adhesive fixing the tip of the optical fiber, in order to prevent both adhesives from mixing with each other. However, even if both adhesives that have flowed into the groove are mixed together, the movement restricting portion is simply formed as a groove. It is made difficult to flow out.

According to a fourth invention of the present application, in addition to the configuration of any of the first to third inventions, an optical adhesive for bonding and fixing the tip of the optical fiber is an ultraviolet curable type. An epoxy adhesive is used, and an adhesive for fixing the holding member is an ultraviolet curable acrylic adhesive.
In other words, an epoxy optical adhesive that is highly transparent with respect to the wavelength of the laser beam and has a small curing shrinkage is used for bonding and fixing the tip of the optical fiber, and curing is used for bonding and fixing the optical fiber holding member. Using an acrylic adhesive with a high speed, it is possible to shorten the bonding work time while ensuring necessary optical characteristics.
In addition, both bonding positions can be irradiated with ultraviolet rays at the same time, and both can be cured at the same time, and the work process of the bonding work can be simplified.

The fifth invention of the present application has a refractive index difference between the refractive index of the optical adhesive and the refractive index of the optical fiber in addition to the configuration of any of the first to fourth inventions. The optical adhesive is configured to be smaller than the refractive index difference between the refractive index of the optical adhesive and the optical waveguide, and conforms to the refractive index of the optical adhesive on the light incident end surface of the optical waveguide. An antireflection film is formed.
That is, when the tip of the optical fiber is bonded to the light incident end face of the optical waveguide of the second harmonic generation element, the refractive index differs from the optical fiber, the optical adhesive, and the optical waveguide along the optical path of the laser beam. You will pass through three areas.
Therefore, as it is, reflection occurs due to the difference in refractive index and returns to the semiconductor laser element as light, which becomes a factor that makes the emission wavelength and optical output of the semiconductor laser element unstable.
For this reason, an antireflection film called an AR coating is formed to suppress reflection at the interface.

At this time, there is a problem in which part the antireflection film is formed in relation to the assembly process of the light source device.
That is, since the optical fiber positioning adjustment with respect to the second harmonic generation element is performed in a state where the semiconductor laser element emits light, prior to the optical fiber positioning adjustment with respect to the second harmonic generation element, the semiconductor laser element and the optical fiber A module assembled with is prepared.
This module is provided with a long optical fiber for the convenience of assembly work in the subsequent process, and the positioning adjustment is performed by cutting the long optical fiber into an appropriate length.
It is not preferable to expose the module in which the semiconductor laser element and the optical fiber are assembled to a high temperature environment for forming a thin film. Therefore, after the optical fiber is cut to an appropriate length, an antireflection film is formed on the cut surface. It is better to avoid working.

  Therefore, an anti-reflection film is not formed on the tip of the optical fiber, and an optical adhesive having an index of refraction as close as possible to that of the optical fiber is used. In order to suppress reflection at the interface with the agent as much as possible, and to suppress reflection at the interface between the optical adhesive that causes a large refractive index difference and the optical waveguide of the second harmonic generation element, An antireflection film set in accordance with the refractive index of the optical adhesive is formed on the incident end face.

According to the first aspect of the invention, the holding member is held near the tip of the optical fiber so that the position adjustment of the optical fiber can be easily performed, and a long time is required for bonding and fixing the holding member. As a result, the incident efficiency of the laser light into the optical waveguide can be improved while shortening the time required for the assembly work of the light source device as much as possible.
According to the second aspect of the invention, by providing a movement restricting portion for restricting the movement of the adhesive fixing the holding member and the optical adhesive fixing the tip of the optical fiber, The adhesive can be prevented from being altered, and the optical properties of the adhesive due to the alteration of the adhesive or the positional fluctuation at the time of curing can be prevented, and the characteristics of the light source device can be maintained well.

According to the third aspect of the present invention, the characteristics of the light source device can be favorably maintained with a simple configuration by preventing changes in the optical properties of the adhesive due to the alteration of the adhesive or fluctuations in position during curing.
According to the fourth aspect of the invention, both the bonding positions can be irradiated with ultraviolet rays at the same time, and both can be simultaneously cured in a short time, simplifying the work process of the bonding work, and the light source device The assembly work time can be further reduced.
According to the fifth aspect of the invention, reflection of laser light can be suppressed as much as possible at the interface between the optical fiber and the optical adhesive, and at the interface between the optical adhesive and the optical waveguide. The operating characteristics of the light source device can be stabilized.

Hereinafter, an embodiment in which the light source device of the present invention is provided as a light source for exposure in a photographic print system will be described with reference to the drawings.
The photographic print system DP exemplified in the present embodiment is known as a so-called digital minilab machine, and as shown in the block configuration diagram of FIG. 8, developed photographic film, memory card, MO or CD. An image input device IR for inputting image data for producing a photographic print from -R and the like, and an exposure / development device EP for exposing the photographic paper 2 based on the image data input by the image input device IR Has been.

[Schematic configuration of image input device IR]
As schematically shown in FIG. 8, the image input device IR includes a film scanner 3 for reading frame images of a photographic film, an external input / output device 4 including a memory reader, an MO drive, a CD-R drive, and the like, A personal computer is provided with a main controller 5 for controlling the film scanner 3 and the external input / output device 4 in addition to controlling the film scanner 3 and the external input / output device 4. Further, the main controller 5 includes a finished print. A monitor 5a that displays a simulated image that simulates an image and various types of control information is connected to a console 5b that is used for manual setting of exposure conditions and for input of control information.

[Overall configuration of exposure / development apparatus EP]
The exposure / development apparatus EP includes an image exposure apparatus EX, a development processing apparatus PP for developing the photographic paper 2 exposed by the image exposure apparatus EX, and a photographic paper drawn from the photographic paper magazine 6 inside the casing. And a photographic paper transport system PT that transports 2 to the development processing apparatus PP by a number of transport rollers 9 or the like.
Although not shown, a sorter is provided outside the casing of the exposure / development apparatus EP to classify the photographic paper 2 that has been developed and dried by the development processing apparatus PP for each order. A conveyor 10 for conveying the photographic paper 2 is provided on the upper surface of the casing.
Further, in the middle of the conveyance path of the photographic paper conveyance system PT, a cutter 11 for cutting the long photographic paper 2 drawn from the photographic paper magazine 6 into a set print size, and a plurality of conveyance rows of the photographic paper 2 are conveyed. A sorting device 12 for sorting into rows is provided.

[Configuration of image exposure apparatus EX]
The image exposure apparatus EX is composed mainly of an exposure unit 13 that exposes and forms an image on the photographic paper 2 and an exposure control apparatus 14 that controls the exposure unit 13.
[Configuration of Exposure Unit 13]
The exposure unit 13 employs a so-called laser beam exposure method in which an intensity-modulated laser beam is scanned on the photographic paper 2 to expose and form an image on the photographic paper 2, and the schematic configuration is shown in the block diagram of FIG. Shown in configuration diagram.
The exposure unit 13 includes a red light source device 21, a green light source device 22, a blue light source device 23, and an acoustooptic modulator 24 (for modulating the intensity of the laser beam emitted from the green light source device 22 and the blue light source device 23). (Hereinafter abbreviated as “AOM element 24”), a mirror 25 that bends the optical path of the laser beam, a spherical lens 26, a cylindrical lens 27, a polygon mirror 28 that is rotationally driven by a motor (not shown), A lens group 29 having an f-θ characteristic and a surface tilt correction function is provided.

[Configuration of light source devices 21, 22, and 23]
Although not shown, the red light source device 21 includes a red semiconductor laser element and a condensing lens that condenses the emitted light of the red semiconductor laser element. Unlike the green light source device 22 and the blue light source device 23, the red light source device 21 is a semiconductor laser. The intensity of the emitted laser beam is modulated by directly modulating the drive current of the element.
The green light source device 22 and the blue light source device 23 have the same basic configuration, and these configurations will be described by using the green light source device 22 as a representative.
As shown in the side view of FIG. 1 and the perspective view of FIG. 6, the green light source device 22 generates a near-infrared semiconductor laser device 22a and a second harmonic of the laser beam emitted from the near-infrared semiconductor laser device 22a. The second harmonic generator 22b, and the wavelength component of the fundamental wave, that is, the wavelength component of the laser beam emitted from the near-infrared semiconductor laser device 22a, are removed from the emitted light from the second harmonic generator 22b. And a condensing lens unit 22d for condensing the second harmonic laser beam that has passed through the filter unit 22c to the light receiving opening of the AOM element 24.

As shown in FIG. 1, the near-infrared semiconductor laser device 22a supports a laser housing 32 containing a semiconductor laser element 31 and one end of an optical fiber 36 attached to the light emission opening side of the laser housing 32. A fiber support member 33 that supports the laser housing 32, and a thermoelectric cooling device 35 that adjusts the temperature of the semiconductor laser element 31. The light is guided to the second harmonic generator 22b by the optical fiber 36 that is accurately positioned at the light emission position of the laser element 31.
The optical fiber 36 forms a so-called fiber Bragg grating in which the refractive index is changed at a constant period in the optical axis direction in the core portion. The action of the fiber Bragg grating causes the emission wavelength and light of the semiconductor laser element 31 to be changed. The output is stabilized.

As shown in FIG. 1 and the like, the second harmonic generation device 22b includes an elongated rod-shaped second harmonic generation element 41 and a holding member that holds near the tip of the optical fiber 36 on the second harmonic generation element 41 side. 44, a collimating lens 45 that collimates the light emitted from the second harmonic generation element 41, and a collimating lens support member 46 that supports the collimating lens 45. The holding member 44, the second harmonic generation element 41, and the collimation are provided. The lens support member 46 is supported by a common support base 42. That is, the support base 42 is configured by integrally forming a holding member support portion 42 a that supports the holding member 44 and an SHG support portion 42 b that supports the second harmonic generation element 41.
The support 42 is further supported by the thermoelectric cooling device 43.

The second harmonic generation element 41 is an optical waveguide type second harmonic generation element, and as shown in the perspective view of FIG. 5, a periodic polarization inversion structure 41b is formed in the optical waveguide 41a. The optical waveguide 41a is positioned at one end (light incident end) of the optical waveguide 41a in a state where the tip of the optical fiber 36 is supported by the holding member 44. FIG. 5 schematically shows the optical waveguide 41a and the periodic polarization inversion structure 41b in order to make them easy to understand. The actual outer shape is elongated as shown in FIG. It is formed in a rod shape.
In the present embodiment, LiNbO ₃ is used as the substrate of the second harmonic generation element 41, the optical waveguide 41a is formed by a proton exchange method or the like, and the periodically poled structure 41b is an electric field application method or a Ti diffusion method or the like. And by periodically inverting the polarization.

FIG. 4 schematically showing the attachment state of the tip of the optical fiber 36 and the second harmonic generation element 41, FIG. 2 showing the vicinity of the fixing portion of the holding member 44 enlarged in plan view, and enlarged in side view. As shown in FIG. 3, the tip of the optical fiber 36 exposed from the holding member 44 is attached to the light incident end face of the optical waveguide 41 a formed in the second harmonic generation element 41 with an optical adhesive GL1. The holding member 44 is fixed on the holding member support portion 42a of the support base 42 with an adhesive GL2.
However, different types of adhesives are used for the optical adhesive GL1 for fixing the tip of the optical fiber 36 and the adhesive GL2 for fixing the holding member 44 to the support base 42, and the holding member 44 is fixed. As the adhesive GL2, an adhesive having a faster curing rate than the optical adhesive GL1 for fixing the tip of the optical fiber 36 is used.
Specifically, an ultraviolet curable epoxy adhesive is used as the optical adhesive GL1 for fixing the tip of the optical fiber 36, and an ultraviolet curable adhesive is used as the adhesive for fixing the holding member 44. The acrylic adhesive is used.

As apparent from FIG. 2 and the like, the amount of adhesive necessary for fixing the holding member 44 is much larger than the amount of adhesive required for fixing the tip of the optical fiber 36. The adhesive GL2 for fixing the holding member 44 can be cured in a relatively short time by properly using the type of adhesive as described above.
As the adhesive GL2 for fixing the holding member 44, the use of an adhesive having a fast curing time causes a relatively large shrinkage at the time of curing. However, as shown in FIG. By evenly applying the adhesive GL2, the shrinkage force at the time of curing is balanced, and the position fluctuation of the holding member 44 can be sufficiently suppressed.

The hardening operation of the optical adhesive GL1 for fixing the tip of the optical fiber 36 and the hardening operation of the adhesive GL2 for fixing the holding member 44 are performed simultaneously, and the holding member 44 is operated by a manipulator (not shown). After the position adjustment is completed by appropriately moving, both the tip position of the optical fiber 36 and the lower end portion of the holding member 44 are collectively irradiated with ultraviolet rays and cured. The operation of applying the adhesives GL1 and GL2 may be performed before the position adjustment of the holding member 44 or after the position adjustment is completed.
As described above, the curing operation of the optical adhesive GL1 for fixing the tip of the optical fiber 36 and the curing operation of the adhesive GL2 for fixing the holding member 44 are simultaneously performed, so that both uncured Since the adhesives GL1 and GL2 are present in close proximity, it is necessary to prevent the mixed uncured adhesive from changing the properties of the adhesive at the bonding site.
Therefore, as shown in FIG. 3 and the like, a groove 42c is formed between the attachment position of the holding member 44 and the mounting position of the second harmonic generation element 41 on the support base 42 to fix the holding member 44. It is provided as a movement restricting portion GS for restricting the movement of the adhesive GL2 and the optical adhesive GL1 for fixing the tip of the optical fiber 36. Even if different types of adhesive are mixed in the groove 42c, It does not affect the bonding location.

Further, since the tip of the optical fiber 36 is fixed by the optical adhesive GL1 as described above, the optical adhesive GL1 is also used for preventing the reflection of the laser beam at each interface on the optical axis. It is necessary to consider existence.
Because of various circumstances, it is not easy to form an antireflection film at the tip of the optical fiber 36. Therefore, the difference in refractive index between the refractive index of the optical adhesive GL1 and the refractive index of the optical fiber 36 can be reduced. By making the refractive index of the optical adhesive GL1 as close as possible to the refractive index of the optical fiber 36 so as to be smaller than the refractive index difference between the refractive index of the adhesive GL1 and the refractive index of the optical waveguide 41a. Reflection of the laser beam at the interface between the tip of the substrate and the optical adhesive GL1 is suppressed.

As a result, the refractive index difference at the interface between the optical adhesive GL1 and the optical waveguide 41a becomes relatively large. However, as shown in FIG. An antireflection film AR1 adapted to the refractive index of the adhesive GL1 is formed to sufficiently reduce the reflection of the laser beam at this interface. Further, an antireflection film AR2 assuming an air interface is formed on the light emitting end face of the optical waveguide 41a. These antireflection films AR1 and AR2 can be constituted by dielectric multilayer films, for example.
By suppressing the reflection of laser light at each interface in this way, the return light to the semiconductor laser element 31 is suppressed, and the action of the fiber Bragg grating formed on the optical fiber 36 is made more effective.

The filter unit 22 c includes an infrared light absorption filter 51 that absorbs the wavelength component of the fundamental wave emitted from the second harmonic generation element 41, and the infrared light absorption filter 51 is supported by a filter support base 52. ing.
On the light incident surface of the infrared light absorption filter 51, an antireflection film for reducing the reflectance of light of the second harmonic wavelength component emitted from the second harmonic generation element 41 is formed. On the opposite light emitting surface, a part of the light of the second harmonic wavelength component emitted from the second harmonic generating element 41 is reflected toward the output adjusting photodiode 55 of the semiconductor laser element 31. A reflective film is formed.
The filter support base 52 includes an incident side through hole 52 a for allowing the light emitted from the second harmonic generation device 22 b to pass toward the infrared light absorption filter 51, and the light emission of the infrared light absorption filter 51. A reflection-side through hole 52b for allowing the second harmonic reflected by the surface to pass toward the photodiode 55 is formed.

Of the fundamental wave emitted from the second harmonic generation element 41 and incident on the infrared light absorption filter 51 and the second harmonic wave, the fundamental wave is absorbed in the process of passing through the inside of the infrared light absorption filter 51. The second harmonic wave passes through the inside of the infrared light absorption filter 51 without being attenuated and reaches the light emitting surface, and a part thereof is reflected. The other portion that has passed through the light exit surface is directed toward the condenser lens unit 22d.
The detection signal of the photodiode 55 is input to an APC circuit (not shown), and the drive current of the semiconductor laser element 31 is adjusted so that the detection signal of the photodiode 55 becomes a constant value.

As shown in FIG. 1 and the like, the condenser lens unit 22d includes a condenser lens 61, a lens holder 62 that supports the condenser lens 61, and a lens support base 63 that supports the lens holder 62. The support base 63 is formed with a through hole 63 a for allowing the second harmonic transmitted through the infrared light absorption filter 51 to pass therethrough.
The near-infrared semiconductor laser device 22a, the second harmonic generation device 22b, and the filter unit 22c are mounted on the support plate 65, and the support plate 65 and the condenser lens unit 22d are mounted on the basic support plate 66. It has been.
The configuration of the green light source device 22 has been described above. However, as described above, the components of the blue light source device 23 are the same as the components of the green light source device 22, and the oscillation wavelength of the semiconductor laser element to be used, the second The portions related to the wavelength of light, such as the period of the periodically poled structure of the harmonic generation element, are different.

[Configuration of Exposure Control Device 14]
As schematically shown in FIG. 7, the exposure control device 14 exposes red, green and blue exposure image data input from the image input device IR in order to control the exposure unit 13 having the above configuration. A look-up table 71 for correcting the image data in consideration of the exposure characteristics of the unit 13, an image data memory 72 for storing the image data corrected by the look-up table 71 for each of red, green and blue colors, red, A D / A converter 73 that is provided for each color of green and blue and D / A converts the output data of the image data memory 72, and AOM that is modulated according to the input signal from the D / A converter 73 for green and blue The AOM control circuit 74 that generates a drive signal for the element 24 and the red light source device 21 according to the input signal from the D / A converter 73 for red. A LD driving circuit 75 for modulating the driving current of the semiconductor laser device is provided.

When the operator inputs image data to be printed from the film scanner 3 or the external input / output device 4, image processing or the like is appropriately performed, and the image data for exposure after image processing is transmitted to the lookup table 71.
Based on the red, green and blue exposure image data input from the image input device IR, the red, green and blue laser beams intensity-modulated by the AOM element 24 and the LD drive circuit 75 The laser beam that passes through and is irradiated on the reflection surface of the polygon mirror 28 and reflected by the reflection surface of the polygon mirror 28 that is driven to rotate is condensed on the photographic paper 2 by the lens group 29. The scanning direction of the laser beam (main scanning direction) is orthogonal to the conveyance direction (sub-scanning direction) of the photographic paper 2, and an image to be printed on the photographic paper 2 is scanned by the scanning of the laser beam and the conveyance movement of the photographic paper 2. Formed as a latent image. This is developed in the development processing apparatus PP and finished as a photographic print.

[Another embodiment]
Hereinafter, other embodiments of the present invention will be listed.
(1) In the above embodiment, both of the optical adhesive GL1 for fixing the optical fiber 36 and the adhesive GL2 for fixing the holding member 44 that holds the optical fiber 36 are ultraviolet curable. However, other curing type adhesives such as a thermosetting type may be used. In particular, as the adhesive GL2 for fixing the holding member 44, various adhesives such as a two-component mixed type can be selected, and any adhesive can be used with emphasis on the curing speed.
(2) In the above embodiment, the case where the light source device of the present invention is used as the exposure light source of the photographic print system DP is exemplified. However, the present invention is applied to various applications where it is desired to generate a second harmonic of a short wavelength. Applicable.
(3) In the above embodiment, the case where the holding member 44 of the optical fiber 36 and the second harmonic generation element 41 are supported by the common support base 42 is exemplified. You may comprise separately a stand and the support stand of the 2nd harmonic generation element 41. FIG.

The side view of the light source device concerning embodiment of this invention The top view near the fixed position of the optical fiber concerning an embodiment of the invention Side view of the vicinity of the fixing position of the optical fiber according to the embodiment of the present invention The figure which shows the connection state of the optical fiber concerning embodiment of this invention, and a 2nd harmonic generation element The perspective view of the 2nd harmonic generation element concerning embodiment of this invention The perspective view of the light source device concerning embodiment of this invention 1 is a schematic configuration diagram of an image exposure apparatus according to an embodiment of the present invention. 1 is a schematic configuration diagram of a photo print system according to an embodiment of the present invention.

Explanation of symbols

31 Semiconductor laser element 36 Optical fiber 41 Second harmonic generation element 42 Support base 42a Holding member support part 42b SHG support part 42c Groove 44 Holding member AR1 Antireflection film GS Movement restriction part

Claims (5)

A light source device comprising: a semiconductor laser element; an optical waveguide type second harmonic generation element; and an optical fiber that guides the emitted light of the semiconductor laser element to the optical waveguide of the second harmonic generation element,
A holding member for holding the tip of the optical fiber near the second harmonic generation element side in a state where the tip is exposed;
The tip of the optical fiber on the second harmonic generation element side is fixed to the light incident end face of the optical waveguide with an optical adhesive,
A light source device in which the holding member is configured to be fixed to a support base with an adhesive having a faster curing speed than the optical adhesive. The support base is configured by integrally forming a holding member support portion that supports the holding member and an SHG support portion that supports the second harmonic generation element,
An adhesive for fixing the holding member and an optical adhesive for fixing the tip of the optical fiber between the bonding position of the holding member and the mounting position of the second harmonic generating element on the support base. The light source device according to claim 1, further comprising a movement restricting portion for restricting movement.   The light source device according to claim 2, wherein the movement restricting portion is configured by forming a groove between an adhesion position of the holding member and an attachment position of the second harmonic generation element. The optical adhesive for bonding and fixing the tip of the optical fiber is an ultraviolet curable epoxy adhesive,
The light source device according to any one of claims 1 to 3, wherein an adhesive for fixing the holding member is an ultraviolet curable acrylic adhesive. The refractive index difference between the refractive index of the optical adhesive and the refractive index of the optical fiber is configured to be smaller than the refractive index difference between the refractive index of the optical adhesive and the refractive index of the optical waveguide. And
The light source device according to any one of claims 1 to 4, wherein an antireflection film adapted to a refractive index of the optical adhesive is formed on a light incident end face of the optical waveguide.

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