TWI422885B - Optical device - Google Patents

Description

Optical device

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an optical device, and more particularly to an optical device for bonding a light beam emitted from a light source to an optical fiber.

Conventionally, in a method of concentrating a light beam emitted from a light source by an optical system and bonding it to an optical fiber, a transparent dielectric block whose light source side has been chamfered is disposed on an optical path of a light beam passing through the optical system. The body optically contacts the optical fiber with the uncut side (the exit end face) of the dielectric block, thereby reducing noise generated by returning the light reflected by the incident end face of the optical fiber to the light source.

However, in the optical device described above, in the case of the components disposed in the optical path, there is a problem that foreign matter remaining (dust collecting) is adhered around the component to deteriorate optical characteristics, particularly in light concentrating (high optical density) The part, that is, the exit end face of the dielectric block and the core of the incident end face of the optical fiber, the dust collection is obvious. Therefore, in the exit end face of the dielectric block and the incident end face of the optical fiber, pressure is generated in order to perform the above-described optical contact, and the foreign matter is pressed by the force and adhered, and the adhered foreign matter is not easily removed. If the foreign matter adheres, there is a fear that the combination of the light is scattered and the optical contact is poor, and the reliability of the light source is lowered.

Therefore, a method has been disclosed in which a dielectric block is adhered to the inner surface of a cylindrical member (brake) with a resin, and the stopper is brought into contact with a sleeve disposed around the optical fiber, whereby the incident end face of the optical fiber is A space is provided between the dielectric blocks to prevent foreign matter from adhering (Patent Document 1).

[Patent Document 1] Japanese Patent Publication No. 6-148471

However, regarding the above foreign matter, an organic substance which may be an organic molecule generated from an adhesive other than an organic molecule remaining in the atmosphere may be considered. Usually, the adhesive is used for fixing the optical member disposed inside the optical device, fixing the optical fiber and the sleeve disposed around the optical fiber, and the like. Therefore, in the method of using the above-described brake, there is a fear that the organic molecules generated from the adhesive for fixing the brake and the sleeve are wound around the sealed space and adhere to the core of the incident end face of the optical fiber. In particular, in the case where an adhesive is also used for fixing the brake and the dielectric block, the possibility of the adhesion is further increased due to the organic molecules generated from the adhesive.

In addition, in the case where an organic molecule generated by an adhesive attached to an optical member disposed inside the optical device or an organic molecule remaining in the atmosphere may be present on the incident end surface of the optical fiber, the organic molecule may be present as described above. Concerns about the core attached to the incident end face of the fiber.

In addition, since the number of parts of the brake portion is increased and the cost of parts is increased because the brake is used, in the optical device, since it is necessary to stably maintain the state in which the incident end faces of the light source and the optical fiber are optically combined with the micron level, it is necessary to accurately The positioning of the brake and the dielectric block is performed, and the positioning is more costly to manufacture.

Further, the present inventors have found that, in the case where the vibration wavelength of a light source such as a laser is 160 nm to 500 nm, the energy density of the light beam passing through the incident end face of the optical fiber and/or the exit end face of the dielectric block is 1.0 mW/ In the high energy density region of μm ² , the incident end surface of the optical fiber and the exit end surface of the dielectric mass are optically contacted. When the light beam is generated from the light source, the incident end surface of the core and the exit end surface of the inductor are fused, and the optical fiber is fused. The occurrence of detachment, vibration, and the like causes the incident end face of the optical fiber and/or the exit end face of the dielectric block to be peeled off to cause defects, which may lower the light transmittance.

The present invention has been made in view of the circumstances, and an object thereof is to provide an optical device which suppresses adhesion of foreign matter at a low cost, further prevents fusion of an optical fiber in a high energy density region, and has high reliability.

An optical device according to the present invention includes: a light source; an optical system that condenses a light beam emitted from the light source; a dielectric block disposed on an optical path of a light beam passing through the optical system; and an optical fiber configured to pass the optical device a light beam of the dielectric block is incident from an end face of the core; the optical device is characterized in that at least between the incident end face of the optical fiber and the exit end face of the dielectric block, at least the incident end face of the core is located a portion where the exit end face of the dielectric block is separated, and a portion of the incident end surface of the optical fiber that surrounds the incident end surface of the core is pressed against the dielectric block to form an incident end face surrounding the core Confined space.

In addition, the "portion of the incident end surface of the optical fiber surrounding the incident end surface of the core" may be a part of the incident end surface of the optical fiber other than the core incident end surface, or may be a part. However, this portion must be such that the incident end face of the core is completely surrounded to form a closed space with respect to the incident end face of the core.

In the optical device according to the present invention, when the optical fiber includes a coating layer around the core, at least a part of an end surface of the cladding layer adjacent to an incident end surface of the core is located in the dielectric block. The position where the exit end faces are separated.

Another optical device according to the present invention includes: a light source; an optical system that condenses a light beam emitted from the light source; a dielectric block disposed on an optical path of a light beam that passes through the optical system; and an optical fiber configured to pass a light beam of the dielectric block is incident from an end surface of the core; and a sleeve is disposed around the optical fiber from a position where the incident end surface of the optical fiber protrudes to a predetermined position of the traveling direction of the light beam; the optical The device is characterized in that at least the incident end face of the core is located at a position separated from the exit end face of the dielectric block between the incident end face of the optical fiber and the exit end face of the dielectric block, from the optical fiber The end surface of the sleeve projecting from the incident end surface is pressed against the dielectric block to form a sealed space surrounding the incident end surface of the core.

It is preferable that the member forming the sealed space or the member contacting the inside of the sealed space does not include a member composed of organic molecules. Further, specifically, a member composed of organic molecules means an adhesive.

The incident end face of the optical fiber and/or the exit end face of the dielectric block are covered with an AR film to prevent reflection of a light beam emitted from the light source.

Further, preferably, when the wavelength of the light beam is λ, the distance L between the incident end face of the core and the exit end face of the dielectric block is L = n λ / 2 ± λ / 8 (n is Integer).

The wavelength of the light beam is preferably from 160 nm to 500 nm. It is preferable that the energy density of the light beam is 1.0 mW/μm ² or more when incident on the incident end surface of the optical fiber.

The image exposure apparatus of the present invention is characterized in that the optical device is provided as an exposure light source.

According to the optical device of the present invention, the portion of the incident end surface of the optical fiber that surrounds the incident end surface of the core is pressed toward the exit end face of the dielectric block, for example, the incident end face of the optical fiber having the hole surrounding the incident end face of the core, The exit end face of the dielectric block and the portion of the incident end face of the optical fiber that surrounds the core are elastically deformed to form a sealed space surrounding the incident end face of the core. By providing a sealed space at least between the incident end surface of the core and the exit end surface of the dielectric block, it is possible to reduce organic molecules or the like which may be generated from an adhesive which is fixed to an optical member or the like disposed inside the optical device. Since the foreign matter is mixed into the inside of the sealed space, it is possible to suppress the foreign matter from adhering to the portion where the light is concentrated, that is, the incident end surface of the core. In addition, even when a small amount of foreign matter is mixed into the sealed space, foreign matter can be prevented from being pushed to The incident end face of the core prevents the adhesion of foreign matter. Thereby, it is possible to suppress light scattering caused by foreign matter and a decrease in bonding efficiency, and it is possible to improve the reliability of the light source.

In addition, in order to provide the sealed space without using other components such as a brake, it is only necessary to add a processing step such as forming a concave portion to the incident end surface of the optical fiber and/or the output end surface of the dielectric block, so that the component cost can be reduced. It also reduces the manufacturing cost caused by the high-precision positioning of the brake and the dielectric block.

In addition, with the other device of the present invention, the end face of the sleeve projecting from the incident end face of the optical fiber is pressed toward the exit end face of the dielectric block, so that the exit end face of the dielectric block and the end face of the sleeve are elastically deformed. Forming a sealed space surrounding the incident end surface of the core. Therefore, even when, for example, a small amount of foreign matter is mixed into the sealed space, the foreign matter can be prevented from being pushed to the incident end surface of the core, so that the adhesion of the foreign matter can be suppressed. Thereby, it is possible to suppress light scattering caused by foreign matter and a decrease in bonding efficiency, and it is possible to improve the reliability of the light source.

Further, in order to provide the sealed space without using other components such as a brake, for example, a contact jig or the like is used, and only the end surface of the sleeve is protruded from the incident end surface of the optical fiber to the dielectric block side, and solder is used. The fixed steps are sufficient, so that the cost of the parts can be reduced, and the manufacturing cost caused by the high-precision positioning of the brake and the dielectric block can be reduced.

Further, in the case where the member forming the sealed space or the member contacting the inside of the sealed space does not include a member composed of organic molecules, for example, an adhesive, it is possible to reduce an optical member or the like which may be fixedly disposed inside the optical device. Since the foreign matter such as organic molecules generated by the subsequent agent is mixed into the sealed space, it is possible to suppress the foreign matter from adhering to the portion where the light is concentrated, that is, the incident end face of the core.

In addition, in the case where the incident end face of the optical fiber and/or the exit end face of the dielectric block are covered with an AR film for preventing reflection of the light beam emitted from the light source, the incident end face and the dielectric at the optical fiber can be reduced. The reflection loss of the light beam generated between the exit end faces of the block allows the light to be efficiently guided to the optical fiber.

Further, in the case where the wavelength of the light beam is λ, if the distance L between the incident end face of the core and the exit end face of the dielectric block is L = n λ / 2 ± λ / 8 (n is an integer), The reflection loss at the incident end face of the core and the exit end face of the dielectric block can be reduced.

In the case where the vibration wavelength of the light source is from 160 nm to 500 nm, since the dust is increased due to the increase in energy, the adhesion of the foreign matter can be effectively prevented by the present invention.

In addition, since the light beam incident toward the incident end surface of the optical fiber is efficiently bonded to the optical fiber and is concentrated in a region smaller than the core diameter, the incident end face of the core and the exit end face of the dielectric mass become high energy density. region. In that case, the incident end face of the optical fiber and the exit end face of the dielectric block are optically contacted, and when the light beam is emitted from the light source, the incident end face of the core and the exit end face of the dielectric block are fused. However, by adopting the present invention, since at least a sealed space is provided between the incident end surface of the core and the exit end surface of the dielectric block, the aforementioned fusion can be prevented. Thereby, it is possible to prevent the occurrence of defects such as the incident end face of the optical fiber and/or the exit end face of the dielectric block by the fall of the optical fiber, the vibration, and the like, and the light transmittance is lowered.

Since the image exposure apparatus of the present invention includes an optical device capable of obtaining the above-described effects, exposure of a light source having high reliability can be performed.

Hereinafter, the optical device 1 according to the first embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1A is a side cross-sectional view showing a schematic shape of an optical device 1 according to the first embodiment. Further, in the present embodiment, the upper side of Fig. 1A will be referred to as an upper side for convenience.

As shown in FIG. 1A, the optical device 1 of the present embodiment is roughly configured as follows: a GaN-based semiconductor laser LD is fixed as a thermal block (heat dissipation block) 2 composed of copper or a copper alloy. The light source; the condensing lens 3 is an optical series that condenses the laser light B (light beam B) emitted from the GaN-based semiconductor laser LD; the dielectric block 4 is disposed in the laser beam B that passes through the condensing lens 3. The optical path and the optical fiber 30 are incident on the laser light B passing through the dielectric block 4.

The GaN-based semiconductor laser LD vibrates at a wavelength of, for example, 405 nm, and is connected to the lead-out wiring 2a to which a drive current is supplied. Further, as the GaN-based semiconductor laser LD, a laser that vibrates at a wavelength other than the above 405 nm may be used in a wavelength range of 160 nm to 500 nm. Here, when the vibration wavelength is 160 nm to 500 nm, dust collection increases due to an increase in energy, and therefore, the present invention is effective in preventing adhesion of foreign matter.

The condensing lens 3 is a convex lens which is formed by, for example, molding a resin or an optical glass.

The dielectric block 4 is formed of a member transparent to the laser beam B such as quartz glass, and is formed as an end surface on the side of the collecting lens 3 when the optical path of the laser beam B is disposed, that is, the incident end face 4a. The lower end of the optical fiber 30 side, that is, the end surface 4b, is formed at a right angle to the axis of the optical fiber 30. When the incident end surface 4a has a slope as described above, it is possible to suppress noise generated by the core 5 of the incident end surface 30A of the optical fiber 30 to be returned to the GaN-based semiconductor laser LD due to the reflected light of the laser light B.

Then, the GaN-based semiconductor laser LD, the condensing lens 3, and the dielectric block 4 are optically disposed, and are fixed to the package by, for example, an adhesive to form an integral module.

The optical fiber 30 is composed of a core 5 formed on the shaft core and a coating layer 6 formed around the core 5. Around the optical fiber 30, the cylindrical sleeve 7 is fixed by, for example, an adhesive agent from the incident end surface of the optical fiber 30 toward a predetermined position (not shown) in the traveling direction of the laser light B.

The sleeve 7 is formed of ceramic, glass or metal, or a material composed of a combination thereof. In the case of being formed of ceramic or glass, the side surface is preferably metallized by metal plating or sputtering. Then, after the sleeve 7 is disposed around the optical fiber 30, the end surface 7a of the sleeve 7 on the side of the dielectric block 4 and the incident end surface of the optical fiber 30 are polished to be flat or spherical.

Here, the present invention is characterized in that, as described above, the optical fiber 30 is polished into a flat or spherical incident end surface, and as shown in FIG. 1, it is processed to have a concave portion having a gentle curvature toward the center of the core 5. The incident end face 30A of the GA. At this time, the concave portion GA is formed in a concave shape slightly from the outer side (the core 5 side) of the outer periphery of the cladding layer 6, and the outer incident end surface 6a1 except the concave portion GA of the cladding layer 6 is processed to be located in the sleeve 7 The end faces 7a are in the same plane. The concave portion is formed by a wet etching method in which the incident end surface of the optical fiber 30 is immersed in an aqueous HF solution as an etching solution or a mixed aqueous solution of HF and NH4F. Further, the processing method is not limited to the wet etching method, and it may be controlled by polishing, dry etching using CF4 or the like, dry etching combined with a photoresist process, wet etching, deposition method, or the like.

Then, the incident end surface 30A on which the concave portion GA is formed is coated with an AR (non-reflective) film that prevents reflection of the laser light B by evaporation. Further, the AR film also covers the incident end face 4a and the exit end face 4b of the dielectric block 4. In this manner, when the exit end face 4b of the dielectric block 4 and the incident end face 30A of the optical fiber 30 are connected, since the reflection loss of the laser light B generated between the exit end face 4b and the incident end face 30A can be reduced, Therefore, the laser light B can be efficiently guided to the optical fiber 30. Further, in the present embodiment, the AR film is applied to the incident end surface 30A of the optical fiber 30, the incident end surface 4a of the dielectric block 4, and the emission end surface 4b. However, the present invention is not limited thereto and may be coated with any One end face can also cover either end face or not.

Further, when the AR film is not provided in the optical fiber and the dielectric block, the distance between the incident end face 5a of the core and the exit end face 4b of the dielectric block is L, and the wavelength of the light beam is λ. It is preferable to set L to L = n λ / 2 ± λ / 8 (n is an integer). Fig. 1B shows the relationship between the distance L between the incident end face 5a of the core and the exit end face 4b of the dielectric block and the transmittance, by setting L to n λ/2 ± λ / 8 (n is an integer The reflection loss of the laser light B generated between the exit end face 4b and the incident end face 30A can be reduced.

Then, the optical fiber 30 formed as described above is pressed with the end surface 7a of the sleeve 7 and the outer end surface 6a1 of the cladding layer 6 to the exit end surface 4b of the dielectric block 4 by 6 to 12 N, for example, by an elastic member. The plug of the sleeve and the optical fiber is pressed to a connector type including a socket of a laser light source, a collecting optical system, and a dielectric block, and the optical member 30 is pressed to the optical member 30 by using an elastic member in the connector structure. The electric mass 4 is positioned such that the laser light B passing through the dielectric block 4 is condensed on the incident end face 5a of the core 5. Further, the optical fiber 30 can be repeatedly attached and detached to the exit end face 4b of the dielectric block 4.

When the optical fiber 30 having the incident end face 30A in which the concave portion GA is formed and the dielectric block 4 are pressed, the incident of the core 5 is between the incident end face 30A of the optical fiber 30 and the exit end face 4b of the dielectric block 4. The end face 5a and the inner incident end face 6a2 of the cover layer 6 adjacent to the incident end face 5a, that is, the inner face of the recessed portion GA are separated from the exit end face 4b, and the end face 7a of the sleeve 7 and the outer end face 6a1 of the cover layer 6 are separated. It is in close contact with the exit end face 4b. Thereby, since the sealed space SA surrounding the incident end surface 5a of the core 5 is formed between the incident end surface 30A of the optical fiber 30 and the exit end surface 4b of the dielectric block 4, it is fixedly disposed in the optical device 1. When an adhesive is used for the optical member or the like, foreign matter such as organic molecules generated from the adhesive can be reduced to the inside of the sealed space SA, and the incident of the foreign matter adhered to the core 5 of the laser beam B can be suppressed. End face 5a. Further, as described above, since the end surface 7a of the sleeve 7 and the incident end surface 6a1 on the outer side of the cladding layer 6 are in close contact with the exit end surface 4b, the fixed surface of the sleeve 7 and the optical fiber 30 does not face the sealed space SA, so that it can be prevented. It is possible to mix organic molecules generated from an adhesive agent used for the fixed surface into the sealed space SA.

In addition, even when some foreign matter is mixed into the sealed space SA, the foreign matter can be prevented from being pressed against the incident end surface 5a of the core 5 by the sealed space SA, so that adhesion of foreign matter can be suppressed. Thereby, it is possible to suppress light scattering caused by foreign matter and decrease in bonding efficiency, and it is possible to improve the reliability of the GaN-based semiconductor laser LD.

Further, the sealing space SA can be formed by adding only the processing steps in which the concave portion GA is formed on the incident end surface 30A of the optical fiber 30 without using other components, so that the component cost can be reduced.

Further, in the case where the semiconductor laser LD output using 150 mW or more has a vibration wavelength of 160 nm to 500 nm and a light-emitting region of 7 × 1 μm ² or a 4x optical lens, in the conventional optical fiber having no concave portion GA, the optical fiber is passed through the optical fiber. The cross-sectional area of the incident light source B and the exit end face of the dielectric block is 28 × 4 μm ² , and the incident end face of the core and the exit end face of the dielectric block have a high energy of 1.0 mW/μm ² or more. In the density region, the incident end face of the optical fiber and the exit end face of the dielectric block are optically contacted, and when the laser light B is generated, there is a fear that the incident end face of the core and the exit end face of the dielectric block are fused. However, the sealed space SA is formed as described above, and the incident end surface 5a of the core 5 and the incident end surface 6a2 inside the cladding layer 6 adjacent to the incident end surface 5a are separated from the exit end surface 4b of the dielectric block 4 to prevent the aforementioned Melt.

<Example 1>

Here, a method of processing the incident end surface 30A of the optical fiber 30 of the above embodiment and an embodiment in which the optical fiber 30 after the processing is repeatedly attached and detached to the dielectric block 4 will be described. The optical fiber 30 is a SI-type quartz fiber having a core diameter of 60 μm and a coating layer 6 having a diameter of 125 μm, and is fixed to the sleeve 7 by adhesion. The optical fiber 30 and the sleeve 7 are formed by polishing the incident end surface (the end surface 7a of the sleeve 7, the incident end surface 5a of the core 5, and the incident end surface 6a of the cladding layer 6).

1) The incident end face of the optical fiber 30 was immersed in an aqueous solution which had been mixed at a weight ratio of HF:NH4F:pure water = 0.15:0:0.1, and the above-mentioned optical fiber 30 was etched for 5 hours. As a result, a concave shape having a radius of curvature of about 25 μm was obtained.

2) Thereafter, the polishing process is performed, and the incident end surface 30A having the concave portion GA is formed such that the end surface 7a of the sleeve 7 and the outer surface incident end surface 6a1 of the cladding layer 6 are flush with each other.

3) Then, the incident end surface 30A of the optical fiber 30 in which the concave portion GA is formed as described above is pressed to the optically disposed GaN-based semiconductor laser LD, the collecting lens 3, and the dielectric block by a connector (not shown) The exit end face 4b of the dielectric block 4 of the integral module of the body 4 is repeatedly attached and detached. As a result, it has been confirmed that the foreign matter adheres to the incident end surface 5a of the core 5 of the optical fiber 30 as compared with the conventional optical fiber which does not have the concave portion GA.

4) Further, even when only a small amount of foreign matter adheres, it is possible to easily remove the adhered foreign matter by wiping it with a cotton swab or the like. In the optical fiber which does not have the recessed part GA in the past, the incident end surface of the optical fiber and the exit end surface 4b of the dielectric block 4 are strongly pressed, so that foreign matter mixed between the two ends is attached to the incident end face of the core 5. In contrast, since the concave portion GA is formed on the incident end surface 30A of the optical fiber 30, since the incident end surface 5a of the core 5 is not pressed, it is estimated that the attachment of the foreign matter can be suppressed.

Next, an optical device 1B according to a second embodiment of the present invention will be described in detail with reference to the drawings. Fig. 2 is a side cross-sectional view showing a schematic shape of an optical device 1B according to the second embodiment.

Since the optical device 1B of the present embodiment is substantially the same as the optical device 1 of the above-described first embodiment, only the incident end faces 30B of the optical fibers 30 of different portions will be described in detail. In addition, since the effects of the invention are the same as those of the optical device 1 of the first embodiment, the description thereof is omitted.

The optical fiber 30 of the present embodiment forms a concave portion GB having a shape different from that of the concave portion GA formed on the incident end surface 30A of the optical fiber 30 of the optical device 1. As shown in Fig. 2, the recessed portion GB has a gentle curvature toward the center of the core 5 only on the incident end surface 5a of the core 5, and the incident end surface 30B on which the recessed portion GB is formed is covered by evaporation to prevent the laser light B from being irradiated. Reflected AR (non-reflective) film. When the optical fiber 30 having the incident end face 30B in which the concave portion GB is formed and the dielectric block 4 are pressed, the incident end face of the core 5 is between the incident end face 30B of the optical fiber 30 and the exit end face 4b of the dielectric block 4. The 5a is separated from the exit end face 4b, and the end face 7a of the sleeve 7 and the incident end face 6a of the cover layer 6 are in close contact with the exit end face 4b. Thereby, a sealed space SB is formed between the incident end surface 30B of the optical fiber 30 and the emission end surface 4b of the dielectric block 4.

<Example 2>

Here, a method of processing the incident end surface 30B of the optical fiber 30 of the above embodiment and an embodiment in which the optical fiber 30 after the processing is repeatedly attached and detached to the dielectric block 4 will be described. Further, the present embodiment is the same as the steps up to the above-described first to (1). Therefore, the steps after (2) will be explained.

2) Thereafter, the polishing process is performed, and the incident end surface 30B having the concave portion GB is formed such that the end surface 7a of the sleeve 7 and the incident end surface 6a of the cladding layer 6 are flush with each other.

3) Then, in the same manner as in the above-described first embodiment, the incident end surface 30B of the optical fiber 30 in which the concave portion GB is formed as described above is pressed against the emission end surface 4b of the dielectric block 4, and the detachment is repeated. As a result, in the same manner as in the above-described first embodiment, it has been determined that the foreign matter adheres to the incident end surface 5a of the core 5 of the optical fiber 30, and it is estimated that the adhesion of the foreign matter can be suppressed.

Next, an optical device 1C according to a third embodiment of the present invention will be described in detail with reference to the drawings. Fig. 3 is a side cross-sectional view showing a schematic shape of an optical device 1C according to a third embodiment.

Since the optical device 1C of the present embodiment is substantially the same as the optical device 1 of the above-described first embodiment, only the incident end surface 30C of the optical fiber 30 of a different portion will be described in detail.

The optical fiber 30 of the present embodiment is formed in a concave portion GC having a different shape in the concave portion GA formed by the incident end surface 30A of the optical fiber 30 of the optical device 1. As shown in FIG. 3, the concave portion GC is formed such that the core 5 of the optical fiber 30 and the flat incident end faces 5a, 6a of the cladding layer 6 are formed to be farther away from the end face 7a of the sleeve 7 in the traveling direction of the laser light B, for example, 40. The μm is constituted by the inner faces of the flat incident end faces 5a and 6a of the core 5 and the cladding layer 6. The concave portion GC is formed by coating the coating layer 6 of the optical fiber 30 having the flat end faces 5a and 6a of the core 5 and the cladding layer 6 which have been polished in advance, for example, by using a jig or the like. 7 is formed such that the end surface 7a protrudes more from the side of the dielectric block 4 than the incident end faces 5a, 6a and is fixed by solder, and then the end face 7a of the sleeve 7 is polished to be flat.

Further, the formation of the concave portion GC is not limited to the above-described method. For example, after the optical fiber 30 and the incident end surface 30C of the sleeve 7 are polished to be flat, the immersion in an aqueous solution of HF as an etching solution or a mixed aqueous solution of HF and NH4F is carried out. Wet etching can also be used to form. Then, the incident end surface 30C on which the concave portion GC is formed is coated with an AR (non-reflective) film that prevents reflection of the laser light B by evaporation.

When the optical fiber 30 having the incident end surface 30C in which the recess GC is formed and the sleeve 7 to the dielectric block 4 are pressed, the incident end surface 6a of the cladding layer 6 and the incident end surface 5a of the core 5 are connected to the dielectric block. The exit end face 4b of 4 is separated, and the end face 7a of the sleeve 7 is in close contact with the exit end face 4b. Thereby, a sealed space SC is formed between the incident end surface 30C of the optical fiber 30 and the emission end surface 4b of the dielectric block 4.

Therefore, even when some foreign matter is mixed into the sealed space, the foreign matter can be prevented from being pressed against the incident end surface of the core, so that the adhesion of the foreign matter can be suppressed. Thereby, it is possible to suppress light scattering caused by foreign matter and a decrease in bonding efficiency, and it is possible to improve the reliability of the light source.

Further, in the present embodiment, since the solder is not used instead of the adhesive agent in the fixing of the sleeve 7 and the optical fiber 30, the fixed surface W does not pass from the fixed surface W even if it faces the sealed space SC. Organic molecules are generated, so organic molecules do not mix into the closed space SC. In addition, the fixing of the sleeve 7 and the optical fiber 30 may be a method of fixing the organic molecules without being mixed into the sealed space SC. For example, only a part of the fixing surface W on the sealed space SC side is made of solder, and the other part is not. A method using an adhesive can also be used.

Next, an optical device 1D according to a fourth embodiment of the present invention will be described in detail with reference to the drawings. Fig. 4 is a side cross-sectional view showing a schematic shape of an optical device 1D shown in the fourth embodiment.

Since the optical device 1D of the present embodiment is substantially the same as the optical device 1 of the above-described first embodiment, only the incident end face 30a of the optical fiber 30 and the outgoing end face 4b of the dielectric block will be described in detail. In addition, since the effects of the invention are the same as those of the optical device 1 of the first embodiment, the description thereof is omitted.

The optical device 1D of the present embodiment differs from the above-described first to third embodiments in that the optical fiber 30 is as shown in Fig. 4, the end face 7a of the sleeve 7, the core 5 of the optical fiber 30, and the incident end face 5a of the cladding layer 6, 6a (hereinafter referred to as the incident end face 30a of the optical fiber 30) is polished to be flat, and the concave portion GD is formed not on the optical fiber 30 but on the exit end face 4b of the dielectric block 4.

When the optical fiber 30 and the dielectric block 4 are pressed, the concave portion GD is formed at a position corresponding to the incident end surface 5a of the core 5 so that the circular opening of the concave portion GD surrounds the incident end surface 5a, and is closed so as to be oriented from the exit end surface 4b. The end face 4a is incident and the bottom is spherical. Then, the AR (non-reflective) film that prevents the reflection of the laser light B is coated by evaporation on the emission end surface 4b on which the concave portion GD is formed, the incident end surface 4a, and the incident end surface 30a of the optical fiber 30 by evaporation.

When the exit end face 4b of the dielectric block 4 in which the recess GD is formed is pressed And the optical fiber 30, between the incident end face 30a of the optical fiber 30 and the exit end face 4b of the dielectric block 4, the incident end face 5a of the core 5 and the incident end face 6a of the cladding layer 6a adjacent to the incident end face 5a A part is separated from the exit end face 4b, and the end face 7a of the sleeve 7 and the incident end face 6a from which the portion of the cover layer 6 is removed are in close contact with the exit end face 4b. Thereby, a sealed space SD is formed between the incident end surface 30a of the optical fiber 30 and the emission end surface 4b of the dielectric block 4.

In the present embodiment, the recess GD has a circular shape in the opening of the recess GD as described above, and the bottom portion has a spherical shape. However, the present invention is not limited thereto. For example, in the fifth embodiment shown in FIG. 5, an opening is formed. The concave portion GE formed by the columnar holes of the square corner may be used. In this case, when the exit end face 4b of the dielectric block 4 in which the recess GE is formed and the optical fiber 30 are pressed, between the incident end face 30a of the optical fiber 30 and the exit end face 4b of the dielectric block 4, the core A portion of the incident end surface 5a of the fifth and the incident end surface 6a of the cladding layer 6a adjacent to the incident end surface 5a are separated from the emission end surface 4b, and the end surface 7a of the sleeve 7 and the incident end surface 6a from which the portion of the cladding layer 6 is removed are attached. It is in close contact with the exit end face 4b. Thereby, a sealed space SE is formed between the incident end surface 30a of the optical fiber 30 and the emission end surface 4b of the dielectric block 4.

Further, an optical device 1F according to a sixth embodiment of the present invention will be described in detail by way of examples. Fig. 6 is a side cross-sectional view showing the shape of the front end of the optical fiber of the optical device 1F of the sixth embodiment. Further, in Fig. 6, the horizontal axis represents the distance (μm) in the radial direction of the optical fiber, the vertical axis represents the distance (nm) in the axial direction of the optical fiber, and the coordinate of the vertical axis serves as the relative coordinate of the measurement system.

In the same manner as the optical fiber 30 of the fourth and fifth embodiments, the optical fiber 30 of the present embodiment is formed by flattening the end surface 7a of the sleeve 7 and the incident end surface 30a of the optical fiber 30, and further using an intermediate particle diameter (9 um). An abrasive is polished. As a result, the front end shape as shown in Fig. 6 can be obtained. The incident end face 30a of the optical fiber 30 and the end face 7a of the sleeve 7 have a mountain shape at the front end with the end face 7a of the sleeve 7 projecting more toward the front end side than the incident end face 30a of the optical fiber 30.

Then, in the same manner as in the above-described first embodiment, the optical fiber 30 formed as described above is pressed against the exit end face 4b of the dielectric block 4, and the detachment is repeated. As a result, since the end surface 7a of the sleeve 7 protrudes more than the front end side of the incident end surface 30a of the optical fiber 30, only the end surface 7a of the sleeve 7 is pressed in the exit end surface 4b because the incident end surface 30b and the incident end surface 30a of the optical fiber 30 are pressed. In the same manner as in the above-described first embodiment, it is possible to determine that the foreign matter adheres to the incident end surface 5a of the core 5 of the optical fiber 30, and it is estimated that the foreign matter can be suppressed from being attached.

Further, although the optical device of the above-described embodiment is configured as described above, the optical device of the present invention is not limited thereto, and can be appropriately modified in design.

Next, an image exposure apparatus including the optical device of the present invention as a light source for exposure will be described.

[Configuration of image exposure device]

As shown in Fig. 7, the image exposure apparatus includes a flat movable pedestal 152 for adsorbing and holding the sheet-like photosensitive material 150 on the surface. On the surface of the thick plate-shaped mounting table 156 supported by the four leg portions 154, two guide portions 158 extending in the moving direction of the pedestal are provided. The pedestal 152 is disposed such that its longitudinal direction faces the pedestal moving direction while being supported by the guide portion 158 so as to be movable back and forth. Further, the exposure apparatus is provided with a pedestal driving device 304 (see FIG. 16) which will be described later to drive the pedestal 152 as a sub-scanning means along the guide portion 158.

In the central part of the setting station 156, The gated gate 160 is designed to move across the moving pedestal 152. will The respective ends of the gates 160 are fixed to both side faces of the setting table 156. A gate 162 is disposed, one side of which is provided with a scanner 162, and the other side is provided with a plurality of (for example, two) sensors 164 for detecting the front end or the rear end of the photosensitive material 150. The scanner 162 and the sensor 164 are each mounted to the shutter 160 and fixedly disposed above the movement path of the pedestal 152. Further, the scanner 162 and the sensor 164 are connected to a controller (not shown) for controlling them.

The scanner 162 has a plurality of (for example, 14) exposure heads 166 arranged in a matrix of m columns and n rows (for example, three columns and five rows) as shown in Figs. 8 and 9(B). In this example, four exposure heads 166 are arranged in the third column because of the relationship of the width of the photosensitive material 150. Further, each of the exposure heads arranged in the nth row of the mth column is indicated by the exposure head 166 _mn .

The exposure area 168 of the exposure head 166 has a rectangular shape in which the sub-scanning direction is a short side. Therefore, as the pedestal 152 moves, a strip-shaped exposed region 170 is formed on each of the exposure heads 166 on the photosensitive material 150. Further, the exposure regions of the respective exposure heads arranged in the nth row of the mth column are indicated by the exposure region 168 _mn .

Further, as shown in Fig. 9(A) and Fig. 9(B), the strip-shaped exposed areas 170 are arranged in a line-like arrangement in order to be arranged in the direction orthogonal to the sub-scanning direction. Each of the exposure heads is arranged to be staggered at a predetermined interval (a natural multiple of the long side of the exposure area, twice in this example) in the arrangement direction. Therefore, the portion of the first column between the exposed region 168 ₁₁ and the exposed region 168 ₁₂ that is not exposed can be exposed by the second column of exposed regions 168 ₂₁ and the third column of exposed regions 168 ₃₁ .

As shown in Fig. 10 and Fig. 11, each of the exposure heads 166 ₁₁ to 166 _mn is provided with a digital micromirror device (DMD) 50 manufactured by Texas Instruments, Inc., which is modulated in accordance with image data on each pixel. A spatial light modulation element of the incident beam. The DMD 50 is connected to a controller 302 (see FIG. 16), which will be described later, including a data processing unit and a mirror drive control unit. In the data processing unit of the controller 302, control signals are generated based on the input image data for driving the respective micromirrors in the control region of the DMD 50 in the respective exposure heads 166. In addition, the area to be controlled will be described later. Further, in the mirror drive control unit, the angles of the reflection surfaces of the respective micromirrors of the DMD 50 are controlled by the respective exposure heads 166 based on the control signals generated in the image data processing unit. Further, the angle control with respect to the reflecting surface will be described later.

The optical fiber array light source 66 is disposed on the light incident side of the DMD 50, and is provided with a laser exiting portion in which the exit end portion (light emitting point) of the optical fiber is arranged in a row in a direction corresponding to the longitudinal direction of the exposure region 168. The lens system 67 corrects the laser light emitted from the fiber array light source 66 and condenses it on the DMD; and the mirror 69 reflects the laser light transmitted through the lens system 67 toward the DMD 50. In addition, FIG. 10 schematically shows the lens system 67.

The lens system 67 is as shown in detail in Fig. 11, and is composed of a collecting lens 71 that condenses the laser light B as illumination light emitted from the fiber array light source 66, and a rod-shaped optical homogenizer 72 ( Hereinafter, it is referred to as a rod-shaped homogenizer, and is inserted into the light path of the light passing through the condensing lens 71; and the imaging lens 74 is disposed on the downstream side of the rod-shaped homogenizer 72, that is, on the side of the mirror 69. The condenser lens 71, the rod-shaped homogenizer 72, and the imaging lens 74 cause the laser light emitted from the optical fiber array light source 66 to become a light beam that approaches parallel light and has uniform intensity in the beam cross section, and is incident on the DMD 50. The shape or action of this rod-shaped homogenizer 72 will be described in detail later.

The laser light B emitted from the lens system 67 is reflected by the mirror 69 and is irradiated to the DMD 50 via TIR (total reflection) 稜鏡 70. Further, this TIR 稜鏡 70 is omitted in the tenth figure.

Further, on the light reflection side of the DMD 50, an imaging optical system 51 for imaging the laser light B reflected by the DMD 50 on the photosensitive material 150 is disposed. Fig. 10 is a view schematically showing the imaging optical system 51, as shown in detail in Fig. 11, which is composed of a first imaging optical system composed of lens systems 52 and 54 and composed of lens systems 57 and 58. a second imaging optical system; a microlens array 55 interposed between the imaging optical systems; and an aperture array 59.

The microlens array 55 is formed by arranging a plurality of microlenses 55a corresponding to respective pixels of the DMD 50 in two dimensions. In a position where the laser light B from the corresponding micromirror 62 is incident, each of the microlenses 55a is disposed at the imaging position shifted from the imaging position of the micromirror 62 formed by the lens systems 52, 54 and The separation concentrating position formed by the lens systems 52, 54. In this example, as will be described later, since only 1024 × 256 lines are driven in the 1024 × 768-line micromirrors of the DMD 50, the microlenses 55a are arranged in 1024 × 256 lines corresponding thereto. Further, the arrangement pitch of the microlenses 55a is 41 μm both in the longitudinal direction and in the lateral direction. The microlens 55a of this example has a focal length of 0.19 mm and an NA (number of openings) of 0.11, and is formed of optical glass BK7. Further, the shape of the microlens 55a will be described later. Then, the beam diameter of the laser light B at the position of each microlens 55a is 41 μm.

Further, the above-described aperture array 59 forms a plurality of openings (openings) 59a corresponding to the respective microlenses 55a of the microlens array 55. In the present embodiment, the diameter of the opening 59a is 10 μm.

The first imaging optical system described above magnifies the image of the DMD 50 by a factor of three and forms an image on the microlens array 55. Then, the second imaging optical system magnifies the image passing through the microlens array 55 by 1.6 times and images and projects on the photosensitive material 150. Therefore, as a whole, the image of the DMD 50 is expanded to 4.8 times and projected and imaged on the photosensitive material 150.

Further, in this example, a pair of yokes 73 is disposed between the second imaging optical system and the photosensitive material 150, and the photosensitive material 150 can be adjusted by moving the 稜鏡 pair 73 in the upper and lower directions in FIG. The focus of the image. Further, in the same figure, the photosensitive material 150 is subjected to sub-scanning movement in the direction of the arrow F.

As shown in Fig. 12, the DMD 50 is a mirror device which is formed on a SRAM cell (memory cell) 60 by a micromirror (micromirror) constituting a plurality of pixels (pixels) of a plurality of pixels (for example, 1024 × 768). 62 is arranged in a lattice shape. In each of the pixels, a micromirror 62 supported by a pillar is provided on the uppermost portion, and a high reflectance material such as aluminum is evaporated on the surface of the micromirror 62. Further, the reflectance of the micromirror 62 is 90% or more. In this example, the arrangement pitch is 13.7 μm both in the longitudinal direction and in the lateral direction. Further, a SRAM cell 60 of a gate CMOS fabricated in a general semiconductor memory production line is disposed directly under the micromirror 62 via a pillar including a hinge and a yoke, and the whole system is configured as a monolithic body. .

When the digital signal is written to the SRAM cell 60 of the DMD 50, the micromirrors 62 supported by the pillars are centered on the diagonal and are within ±α degrees (e.g., ±12 degrees) with respect to the substrate side on which the DMD 50 is disposed. tilt. Fig. 13(A) shows a state in which the micromirror 62 is tilted by +α degrees in the ON state, and Fig. 13(B) shows a state in which the micromirror 62 is tilted by -α degrees in the OFF state. Therefore, the tilt of the micromirrors 62 of the respective pixels of the DMD 50 is controlled in accordance with the image signal as shown in Fig. 12, whereby the laser light B incident on the DMD 50 is reflected to the tilt direction of each of the micromirrors 62.

Further, Fig. 12 shows an example in which one portion of the DMD 50 is enlarged and the micromirror 62 is controlled to a state of +α and -α degrees. The ON/OFF control of each of the micromirrors 62 is performed by the controller 302 connected to the DMD 50. Further, a light absorber (not shown) is disposed in a direction in which the laser beam B reflected by the micromirror 62 in the OFF state travels. Although the micromirror 62 of the present embodiment has a skew on the reflecting surface thereof, the skew is omitted in Figs. 12 and 13 .

Further, the DMD 50 is preferably arranged such that its short side and the sub-scanning direction are slightly inclined at a predetermined angle θ (for example, 0.1° to 5°). Fig. 14(A) shows the scanning trajectory of the reflected light image (exposure beam) 53 of each micromirror when the DMD 50 is not tilted, and Fig. 14(B) shows the scanning trajectory of the exposure beam 53 when the DMD 50 is tilted.

In the DMD 50, micromirror rows in which a plurality of micromirrors (for example, 1024) are arranged in the longitudinal direction are arranged in a plurality of arrays (for example, 756 groups) in the short direction, as shown in FIG. 14(B). When the DMD 50 is tilted, the pitch P ₁ of the scanning trajectory (scanning line) of the exposure beam 53 of each micromirror becomes narrower than the distance P ₂ between the scanning lines when the DMD 50 is not inclined, and the resolution can be greatly improved. On the other hand, since the inclination angle of the DMD 50 is small, the scanning width W ₂ when the DMD 50 is inclined and the scanning width W ₁ when the DMD 50 is not inclined are substantially the same.

In addition, the same scanning line is repeatedly exposed (multiple exposure) by different micromirror rows. As such, by multiple exposures, a small amount of exposure position relative to the calibration mark can be controlled, enabling high-definition exposure. Further, the joint portion between the plurality of exposure heads arranged in the main scanning direction is controlled at a small amount of exposure position, thereby achieving connection without height difference.

Further, in addition to tilting the DMD 50, the same effect can be obtained even if the respective micro mirror rows are arranged to be zigzag at a predetermined interval in the orthogonal direction of the sub-scanning direction.

The fiber array light source 66 is composed of a plurality (for example, 14) of optical devices 1 including the optical fibers 30 as shown in Fig. 15A. The other end of the optical fiber 30 is coupled with a second optical fiber 31 having the same core diameter as the optical fiber 30 and having a smaller cladding diameter than the optical fiber 30. As shown in detail in Fig. 15B, the ends of the second optical fiber 31 on the side opposite to the optical fiber 30 are arranged in seven main scanning directions orthogonal to the sub-scanning direction, and are arranged. The laser emitting portion 68 is formed in two rows.

The laser emitting portion 68 formed at the end of the second optical fiber 31 is sandwiched and fixed by two support plates 65 having a flat surface as shown in Fig. 15B. Further, it is preferable that the light-emitting end face of the second optical fiber 31 is provided with a transparent protective plate for protecting glass or the like. The light-emitting end face of the second optical fiber 31 is easily deteriorated due to the high optical density, and the dust can be prevented from adhering to the end surface by arranging the protective plate as described above, and deterioration can be delayed.

In this example, as shown in Fig. 15C, the tip end portion of the laser light-emitting side of the optical fiber 30 having a large cladding diameter is coaxially coupled with a second coating layer having a length of about 1 to 30 cm. Optical fiber 31. These optical fibers 30 and 31 are joined by fusing the incident end faces of the second optical fibers 31 to the exit end faces of the optical fibers 30 in a state in which the respective core axes are aligned. As described above, the diameter of the core 31a of the second optical fiber 31 is the same as the diameter of the core 5 of the optical fiber 30.

Next, the electrical configuration of the image exposure apparatus of this embodiment will be described with reference to Fig. 16. As shown in the figure, the entire control unit 300 is connected to a modulation circuit 301 which is connected to the controller 302 that controls the DMD 50. Further, the entire control unit 300 is connected to the LD drive circuit 303 that drives the optical device 1. Further, the entire control unit 300 is connected to the pedestal driving device 304 that drives the pedestal 152.

[Operation of image exposure device]

Next, the operation of the image exposure apparatus will be described. In each of the exposure heads 166 of the scanner 162, the laser light B emitted from each of the GaN-based semiconductor lasers LD (see FIG. 1) constituting the combined laser light source of the optical fiber array light source 66 is emitted in a divergent state. The optical lens 3 condenses and passes through the dielectric block 4 and converges on the incident end surface 5a of the core 5 of the optical fiber 30. Then, the laser light B that has entered the core 5 of the optical fiber 30 is conducted in the optical fiber 30, and is emitted from the second optical fiber 31 coupled to the exit end face of the optical fiber 30.

When the image is exposed, the image data according to the exposure pattern is input from the modulation circuit 301 shown in Fig. 16 to the controller 302 of the DMD 50, and temporarily stored in the frame memory. This image data indicates data of the density of each pixel constituting the image by a binary value (the presence or absence of the recording of the dot).

The pedestal 152 that sucks the photosensitive material 150 on the surface is moved from the upstream side to the downstream side of the shutter 160 along the guide 158 at a constant speed by the pedestal driving device 304 shown in Fig. 16. When the pedestal 152 passes under the gate 160, if the front end of the photosensitive material 150 is detected by the sensor 164 attached to the shutter 160, the image data memorized by the frame memory is sequentially read for each of the plurality of lines. A control signal is generated for each of the exposure heads 166 based on the image data read by the data processing unit. Then, the mirror driving control unit controls the ON/OFF of each of the micromirrors of the DMD 50 in each of the exposure heads 166 in accordance with the generated control signal. Further, in the case of this example, the size of the above-described micromirror which is one pixel portion is 14 μm × 14 μm.

When the DMD 50 is irradiated with the laser light B from the fiber array light source 66, the laser light reflected when the micromirror of the DMD 50 is in the ON state is imaged on the photosensitive material 150 by the lens systems 54, 58. In this way, the laser light emitted from the fiber array light source 66 is controlled to be ON/OFF on each pixel, and the photosensitive material 150 is in the same number of pixel units as the DMD50 (the exposure area). 168) was exposed. Further, by the photosensitive material 150 and the pedestal 152 moving at a constant speed, the photosensitive material 150 is sub-scanned in the direction opposite to the moving direction of the pedestal by the scanner 162, and a strip-shaped exposure is formed in each of the exposure heads 166. Finish area 170.

The sub-scanning of the photosensitive material 150 by the scanner 162 is completed. When the sensor 164 detects the rear end of the photosensitive material 150, the pedestal 152 is returned to the upstream of the gate 160 by the pedestal driving device 304 along the guiding portion 158. The origin of the side is again moved from the upstream side to the downstream side of the gate 160 along the guide 158 at a constant speed.

Next, an illumination optical system shown in Fig. 11 will be described, which is composed of an optical fiber array light source 66, a collecting lens 71, a rod-shaped homogenizer 72, an imaging lens 74, a mirror 69, and a TIR 70, and The laser light B of the illumination light is incident on the DMD 50. The rod-shaped homogenizer 72 is formed, for example, as a translucent pole of a quadrangular prism shape, and when the laser beam B is advanced while being totally reflected inside, the intensity distribution in the beam section of the laser beam B is uniformized. Further, an anti-reflection film is applied to the incident end surface and the emission end surface of the rod-shaped homogenizer 72 to increase the transmittance. In the above manner, if the intensity distribution in the cross section of the laser beam B of the illumination light can be made highly uniform, the unevenness of the illumination light intensity can be eliminated, and a high-definition image can be exposed on the photosensitive material 150.

1, 1B, 1C, 1D, 1E, 1F. . . Optical device

2. . . Thermal block (heat block)

3. . . Condenser lens (optical system)

30. . . optical fiber

30A, 30B, 30C, 30a. . . Incident end face of the fiber

31. . . Second fiber

4. . . Dielectric block

4a. . . Incident end face of dielectric block

4b. . . Exit end face of dielectric block

5, 31a. . . Core

5a. . . Core incident end face

6. . . Coating

6a. . . Incident end face of the cladding

7. . . casing

7a. . . Incident end face of the casing

B. . . Laser light

GA, GB, GC, GD, GE. . . Concave

LD. . . GaN-based semiconductor laser (light source)

SA, SB, SC, SD, SE, SF. . . hermetic space

50, 250. . . Digital micromirror device (DMD)

51. . . Imaging optics

52, 54. . . Lens system

55. . . Microlens array

55a, 56a, 155a, 355a. . . Microlens

56. . . Concentrating microlens array

57, 58. . . Lens system

59,159. . . Open array

59a, 159a. . . Opening

62. . . Micromirror

66. . . Fiber array light source

68. . . Laser exit department

72. . . Rod homogenizer

150. . . Photosensitive material

152. . . Pedestal

162. . . scanner

166. . . Exposure head

168. . . Exposure area

170. . . Exposure area

Fig. 1A is a side cross-sectional view showing a schematic shape of an optical device according to the first embodiment.

Fig. 1B is a view showing the relationship between the distance L between the incident end face of the core and the exit end face of the dielectric block and the transmission.

Fig. 2 is a side cross-sectional view showing a schematic shape of an optical device according to a second embodiment.

Fig. 3 is a side cross-sectional view showing a schematic shape of an optical device according to a third embodiment.

Fig. 4 is a side cross-sectional view showing a schematic shape of an optical device according to a fourth embodiment.

Fig. 5 is a side cross-sectional view showing a schematic shape of an optical device according to a fifth embodiment.

Fig. 6 is a side cross-sectional view showing the shape of the front end of the optical fiber of the optical device of the sixth embodiment.

Fig. 7 is a perspective view showing the appearance of an image exposure apparatus according to an embodiment of the present invention.

Fig. 8 is a perspective view showing the configuration of a scanner of the image exposure apparatus of Fig. 7.

Fig. 9(A) is a plan view showing an exposed region formed on a photosensitive material, and Fig. 9(B) is a view showing an arrangement of exposure regions of respective exposure heads.

Fig. 10 is a perspective view showing a schematic configuration of an exposure head of the image exposure apparatus of Fig. 7.

Figure 11 is a cross-sectional view of the above exposure head.

Fig. 12 is a partially enlarged view showing the configuration of a digital micromirror device (DMD).

Fig. 13(A) and Fig. 13(B) are explanatory diagrams for explaining the operation of the DMD.

The 14th (A) and 14th (B) drawings show the arrangement of the exposure beam and the plan view of the scanning line in the case where the DMD is not tilted and tilted.

Fig. 15A is a perspective view showing the configuration of a fiber array light source.

Fig. 15B is a front elevational view showing the arrangement of the light-emitting points of the laser emitting portion of the fiber array light source.

Fig. 15C is a view showing the configuration of an optical fiber.

Fig. 16 is a block diagram showing the electrical configuration of the image exposure apparatus.

1. . . Optical device

2. . . Thermal block (heat block)

2a. . . Lead wiring

3. . . Condenser lens

30. . . optical fiber

30A. . . Incident end face of the fiber

4. . . Dielectric block

4a. . . Incident end face of dielectric block

4b. . . Exit end face of dielectric block

5. . . Core

5a. . . Core incident end face

6. . . Coating

6a. . . Incident end face of the cladding

6a1. . . Outer incident end face

6a2. . . Medial incident end face

7. . . casing

7a. . . Incident end face of the casing

B. . . laser

GA. . . Concave

LD. . . GaN-based semiconductor laser

SA. . . hermetic space

Claims (13)

An optical device comprising: a light source; an optical system that condenses a light beam emitted from the light source; a dielectric mass disposed on an optical path of a light beam passing through the optical system; and an optical fiber configured to pass the medium The light beam of the electric mass is incident from the end surface of the core; the optical device is characterized in that at least the incident end surface of the core is located between the incident end surface of the optical fiber and the exit end surface of the dielectric block a portion where the exit end face of the dielectric block is separated, and a portion of the incident end face of the optical fiber that surrounds the incident end face of the core is pressed against the dielectric block to form an incident end face surrounding the core. hermetic space. The optical device according to claim 1, wherein the optical fiber has a coating layer around the core, and an end surface of at least a portion of the cladding layer adjacent to an incident end surface of the core is located at the dielectric The position at which the exit end of the mass is separated. The optical device of claim 1, wherein the incident end face of the optical fiber and/or the exit end face of the dielectric block are covered with an AR film for preventing a light beam emitted from the light source. reflection. An optical device as claimed in claim 1, wherein the wave of the beam In the case of λ, the distance L between the incident end face of the core and the exit end face of the dielectric block is L = n λ / 2 ± λ / 8 (n is an integer). The optical device according to claim 1, wherein the wavelength of the light beam is from 160 nm to 500 nm. The optical device according to claim 1, wherein the energy density of the light beam is 1.0 mW/μm ² or more when incident on an incident end surface of the optical fiber. An optical device comprising: a light source; an optical system that condenses a light beam emitted from the light source; a dielectric mass disposed on an optical path of a light beam passing through the optical system; and an optical fiber configured to pass through the medium a light beam of the electric mass is incident from an end surface of the core; and a sleeve is disposed around the optical fiber from a position where the incident end surface of the optical fiber protrudes to a predetermined position of the traveling direction of the light beam; The method is characterized in that at least between the incident end face of the optical fiber and the exit end face of the dielectric block, at least the incident end face of the core is located at a position separated from the exit end face of the dielectric block, and is incident from the optical fiber. The end surface of the sleeve projecting from the end surface is pressed against the dielectric block to form a sealed space surrounding the incident end surface of the core. The optical device of claim 7, wherein the member forming the sealed space or the member contacting the inside of the sealed space is not included Contains components consisting of organic molecules. The optical device of claim 7, wherein the incident end face of the optical fiber and/or the exit end face of the dielectric block are covered with an AR film for preventing a light beam emitted from the light source. reflection. The optical device of claim 7, wherein, in the case where the wavelength of the light beam is λ, the distance L between the incident end face of the core and the exit end face of the dielectric block is L = n λ / 2±λ/8 (n is an integer). The optical device of claim 7, wherein the wavelength of the light beam is from 160 nm to 500 nm. The optical device according to claim 7, wherein the energy density of the light beam is 1.0 mW/μm ² or more when incident on an incident end surface of the optical fiber. An image exposure apparatus comprising the optical device of the first application of the patent scope as a light source for exposure.