JP2016170315A - Region dividing wavelength plate and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a thin region dividing wavelength plate of 50 μm or less, which can be inserted into a groove formed to cross the light relative to an optical waveguide.SOLUTION: A manufacturing method for a region dividing wavelength plate according to the present invention includes steps of: applying a light alignment film on a glass substrate; aligning a first region of the light alignment film in a first polarizing direction and aligning a second region of the light alignment film in a second polarizing direction, the first region and the second region being divided; applying polymerizable liquid crystal on the light alignment film; irradiating the polymerizable liquid crystal with UV light; further applying polymerizable liquid crystal on the polymerizable liquid crystal and irradiating the liquid crystal with UV light, thereby forming a polymerizable liquid crystal layer; attaching a surface of the glass substrate on which the light alignment film is applied to a polishing table and polishing a surface of the glass substrate opposite to the surface thereof on which the light alignment film is applied to a desired thickness; and cutting the glass substrate into a desired size and detaching the substrate from the polishing table.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a region-dividing wave plate and a method of manufacturing the region-dividing wave plate, and more specifically, in an optical fiber array or an optical waveguide array, the region is divided for each region to be inserted to control the polarization of the optical waveguide. It relates to a wave plate.

  In order to control the polarization of the optical waveguide, a method of digging a groove in the substrate on which the optical waveguide is formed and inserting a polyimide wavelength plate is often used. FIG. 1 is a diagram illustrating a state in which a wave plate is inserted into a substrate on which an optical waveguide is formed. In FIG. 1, an optical circuit 103 including an optical waveguide 102 is formed on a Si substrate 101. A groove 104 having a certain depth and width (specifically, a depth of 150 μm to 200 μm and a width of 20 μm) is formed in a direction perpendicular to the light guiding direction of the optical waveguide 102 on the upper surface of the optical circuit 103. Is inserted with a λ / 2 wave plate 105. The λ / 2 wavelength plate 105 is formed of a polyimide stretched film. Since the refractive index difference dn of the polyimide stretched film is about 0.05, in the light of 1.5 μm, which is the communication wavelength band, the polyimide stretched film has a thickness of about 15 μm. Play a role. Since the optical waveguide has polarization dependency, the polarization of the optical waveguide 102 is changed by inserting a λ / 2 wavelength plate 105, which is a polyimide stretched film, into a groove formed in the substrate as shown in FIG. It becomes possible to control. (See Patent Document 1).

  The polyimide stretched film has a certain polarization direction. Therefore, in an optical waveguide array in which a plurality of optical waveguides are formed on a substrate, in order to insert wave plates having different polarization directions into adjacent optical waveguides, wave plates having different polarization directions are inserted into the respective optical waveguides. There is a need.

  FIG. 2 is a top view showing a waveguide-type polarizing beam splitter 200 in which two wave plates are inserted into one groove. A waveguide-type polarization beam splitter 200 includes an input optical waveguide 201, a Y branch coupler 203 connected to the input optical waveguide 201, and a TE polarization waveguide 204 connected to the output of the Y branch coupler 203 on a substrate 201. And a TM polarization waveguide 205 are formed. Further, the optical waveguide type polarization beam splitter 200 is a TE polarization output in which the 2 × 2 MMI 206 connected to the TE polarization waveguide 204 and the TM polarization waveguide 205 and the output of the 2 × 2 MMI 206 are respectively connected on the substrate 201. An optical waveguide 207 and a TM polarization output optical waveguide 208 are formed.

  On the upper surface of the waveguide-type polarization beam splitter 200, in a direction perpendicular to the light guiding direction of the TE-polarization waveguide 204 and the TM-polarization waveguide 205 so as to cross the TE-polarization waveguide 204 and the TM-polarization waveguide 205. A groove 211 having a certain depth (specifically, a depth of 150 μm to 200 μm) is formed. In the groove 211, a λ / 4 wavelength plate (90 degrees) 212 is inserted so as to cross the TE polarization waveguide 204, and a λ / 4 wavelength plate (0 degrees) 213 is inserted so as to cross the TM-shaped optical waveguide 205. The The groove 211 is formed by dicing.

  In the waveguide type polarization beam splitter 200 of FIG. 2, a λ / 4 wavelength plate (0 degree) 213 and a λ / 4 wavelength plate (90 degrees) 212 are inserted between the Y-branch coupler 203 and the 2 × 2 MMI 206. The TE wave is advanced 90 degrees by the λ / 4 wavelength plate (0 degree) 213, and the TM wave is advanced 90 degrees by the λ / 4 wavelength plate (90 degrees) 212. By shifting the phase of the two lights separated by the Y-branch coupler 203 to + and − by 90 ° and inputting them to the 2 × 2 MMI 206, only one TE-polarized light is supplied to one optical waveguide (TE-polarized output optical waveguide 207). Only the TM polarized light is output to the other optical waveguide (TM polarized output optical waveguide 208) (see Non-Patent Document 1).

  In recent years, with the increase in the number of ports, the number of wavelengths, etc. processed by an optical circuit, the need to integrate a large number of optical processing circuits in one chip for one optical circuit of an optical waveguide has increased. Among them, a circuit for providing polarization control is required, and it is required to integrate the polarization beam splitter shown in FIG. When integrating polarization beam splitters for multiple ports, it is necessary to increase the spacing between adjacent optical waveguides in order to insert different wavelength plates into the respective optical waveguides. For this reason, there is a drawback that the size of the entire circuit becomes large. Furthermore, in order to form an array structure in which a large number of these polarizing beam splitters and the like are integrated, it is necessary to insert a plurality of wave plates into a plurality of grooves or a straight groove perpendicular to the optical waveguide. The thin wave plate is cut at intervals between the optical waveguides and placed at the exact optical waveguide position, and is required to be fixed, which is difficult to work with, resulting in a decrease in yield and an increase in cost. It was.

  As a technique for solving this, a region-divided wave plate in which a phase difference is arbitrarily given in accordance with the position along the in-plane long axis direction of the wave plate is required in one wave plate.

Japanese Patent No. 3501235 Japanese Patent No. 3885936 Japanese Patent No. 3632220 Japanese Patent No. 3767632 Japanese Patent No. 3842102

Yusuke Nasu, Takayuki Mizuno, Ryoichi Kasahara, Takashi Saida, “Temperature Insensitive and Ultra Wideband Silica-based Dual Polarization Optical Hybrid for Coherent Receiver with Highly Symmetrical Interferometer Design,” Tu.3.LeSaleve.4, 37th European Conference and Exhibition on Optical communication 2011 (September 18-22, 2011, Geneva, Switzerland). Photonic Lattice Co., Ltd., “Regional Wavelength Plate for Optical Communication”, http://www.photonic-lattice.com/en/products/region-segmentation-polarizer/waveplate-for-digital-coherent-communication-devices/ Nobuhiro Kawatsuki, Tetsuro Kawakami, and Tohei Yamamoto, “A Photoinduced Birefringent Film with a High Orientational Order Obtained from a Novel Polymer Liquid Crystal,” Adv. Mater. 2001, 13, No. 17, September 3, p1337-1339. Yoshihiro Kawatsuki, Koji Ono, "Photoalignable Polymer Liquid Crystal", Liquid Crystal, Vol. 7, No. 4, 2003, 332 (44)

  In an array in which polarization beam splitters are integrated for multiple ports, a technique is disclosed that uses comb-like film-type wave plates to insert wave plates having different polarization directions into adjacent optical waveguides ( Patent Document 2). FIG. 3 is a perspective view showing an optical circuit 300 in which a comb-like film type wave plate is inserted. The optical circuit 300 includes a Si substrate 301, a plurality of optical waveguides 302a to 302h formed on the Si substrate 301, and a film shape inserted in a direction orthogonal to the light guiding direction of the plurality of optical waveguides 302a to 302h. and a λ / 2 wavelength plate 303.

  The optical circuit 300 of FIG. 3 cuts a 45 ° -direction polyimide stretched film into a comb-like shape by dicing to create a comb-like film-type λ / 2 wavelength plate 303, and includes a plurality of optical waveguides 302a to 302h. It is inserted in a direction orthogonal to the light guiding direction. In this case, the film type λ / 2 wavelength plate 303 is not inserted into all the optical waveguides of the optical circuit 300, but is inserted only into the selected optical waveguide. Therefore, an optical waveguide in which only a part of the optical waveguide is polarized and the polarization is rotated by 90 degrees and an optical waveguide that does not rotate the polarization are realized in one substrate.

  However, it is difficult to machine a 15 μm thin polyimide stretched film into a comb-teeth shape by machining, and since it is formed in a comb-teeth shape, it is weak in mechanical strength and can be easily inserted into a groove. It was difficult. Furthermore, a 250 μm pitch is the limit for cutting and patterning a polyimide wave plate, and it is difficult to produce a patterned wave plate with a pitch smaller than that. In addition, since only a single polarization direction can be created, there is a problem that a plurality of polarization directions cannot be given to the polarization beam splitter 300.

  Although there is a region-dividing wavelength plate made of a photonic crystal (see Non-Patent Document 2), it is very expensive because it is basically manufactured by crystal growth.

  On the other hand, in the field of displays, in recent years, an alignable curable resin called a polymerizable liquid crystal has been developed and used as a retardation film for compensating the visual dependency and color of a liquid crystal display. In addition, since the polymerizable liquid crystal can realize a retardation film having a division pattern by dividing light alignment or rubbing alignment using a mask, the polarization of pixels for the right eye and the left eye is rotated by 90 degrees so that 3D television Is realized.

  The polymerizable liquid crystal is characterized in that it is oriented according to the orientation direction when applied on the photo-alignment film, and is polymerized while maintaining the orientation when mainly irradiated with ultraviolet rays. Therefore, the polymerizable liquid crystal cured after orientation has a large refractive index anisotropy (Δn = 0.1 to 0.2) like the liquid crystal. Since Δn of the polyimide wave plate is about 0.05, it can be seen that it is very large.

  Conventional retardation films have been stretched to have anisotropy and are affixed to a liquid crystal display. However, when this polymerizable liquid crystal is used, a retardation film can be produced by directly applying it to the substrate. In addition, the region-divided wave plate can be formed by combining with the split light alignment by the mask and the split rubbing alignment by the mask.

  On the other hand, when the wavelength plate has a thickness of 50 μm or more, the loss of the optical waveguide increases. Therefore, the thickness of the wave plate has to be 50 μm or less (preferably 15 μm or less). However, conventionally, there has been a problem that the photo-alignment film and the polymerizable liquid crystal cannot be applied and UV-cured on a thin glass substrate of 50 μm or less.

  The present invention has been made in view of such problems, and is a thin region division wave plate having a thickness of 50 μm or less and a region division wave plate that can be inserted into a groove formed so as to cross light with respect to an optical waveguide. The manufacturing method of this is provided.

  A first aspect of the present invention is a method of manufacturing a region-dividing wavelength plate, the step of applying a photo-alignment film on a glass substrate, and orienting the first region of the photo-alignment film in a first polarization direction. And aligning the second region of the photo-alignment film in a second polarization direction, wherein the first region and the second region are arranged separately, and the light A step of applying a polymerizable liquid crystal on the alignment film, a step of irradiating the polymerizable liquid crystal with UV, a further step of applying a polymerizable liquid crystal on the polymerizable liquid crystal and performing UV irradiation to form a polymerizable liquid crystal layer Bonding the surface of the glass substrate coated with the photo-alignment film to a polishing table, and polishing the surface of the glass substrate opposite to the surface coated with the photo-alignment film to a desired thickness; and A glass substrate is cut into a desired size, and the polishing table Characterized in that it comprises the step of stripping al.

  A second aspect of the present invention is a method for manufacturing a region-divided wavelength plate, the step of attaching a glass substrate on a glass plate, wherein the glass substrate partially protrudes from an edge of the glass plate. A step of applying in a state, a step of applying a photo-alignment film on the glass substrate, a first region of the photo-alignment film is aligned in a first polarization direction, and a second of the photo-alignment film Aligning the region in the second polarization direction, wherein the first region and the second region are arranged separately, and applying a polymerizable liquid crystal on the photo-alignment film A step of irradiating the polymerizable liquid crystal with UV, a step of further applying a polymerizable liquid crystal on the polymerizable liquid crystal and performing UV irradiation to form a polymerizable liquid crystal layer, and the glass plate of the glass substrate The part that protrudes from the optical waveguide Characterized in that it comprises the steps of inserting into a groove formed on the optical circuit so as to cross.

  According to a third aspect of the present invention, there is provided a method of manufacturing a region-dividing wavelength plate, the step of attaching a glass substrate on a glass plate, the step of applying a photo-alignment film on the glass substrate, and the photo-alignment film Orienting the first region in the first polarization direction and orienting the second region of the photo-alignment film in the second polarization direction, wherein the first region, the second region, Are disposed separately, a step of applying a polymerizable liquid crystal on the photo-alignment film, a step of irradiating the polymerizable liquid crystal with UV, and a further step of applying a polymerizable liquid crystal on the polymerizable liquid crystal. Performing UV irradiation to form a polymerizable liquid crystal layer, and cutting the glass substrate into a desired size and peeling the glass substrate from the glass plate.

  According to a fourth aspect of the present invention, there is provided the method of manufacturing a region-dividing wavelength plate according to any one of the first to third aspects, the glass substrate, the light distribution film, the polymerizable liquid crystal layer, The total thickness of is formed to be 50 μm or less.

  According to a fifth aspect of the present invention, there is provided a method of manufacturing a region-dividing wavelength plate, the step of applying a photo-alignment film on a glass substrate, and orienting the first region of the photo-alignment film in a first polarization direction. And aligning the second region of the photo-alignment film in a second polarization direction, wherein the first region and the second region are arranged separately, and the light A step of applying a polymerizable liquid crystal on the alignment film, wherein the photo-alignment film and the polymerizable liquid crystal have weak adhesion; a step of irradiating the polymerizable liquid crystal with UV; and the polymerization The method further comprises the steps of: applying a polymerizable liquid crystal on the polymerizable liquid crystal and performing UV irradiation to form a polymerizable liquid crystal layer; and peeling the polymerizable liquid crystal layer from the glass substrate.

  According to a sixth aspect of the present invention, there is provided the method of manufacturing a region-dividing wavelength plate according to any one of the first to fourth aspects, wherein the first region of the photo-alignment film is aligned in a first polarization direction. The step of orienting the second region of the photo-alignment film in the second polarization direction includes covering the photo-alignment film with a striped mask and irradiating UV direct polarization in the first polarization direction; Irradiating the UV-polarized wave in the second polarization direction to a region where the UV-polarized wave in the first direction is not irradiated by shifting the stripe-shaped mask in the pitch direction. It is characterized by.

  A seventh aspect of the present invention is a region-dividing wavelength plate, which is a glass substrate and a photo-alignment film applied on the glass substrate, and the photo-alignment film is oriented in the first polarization direction. A first alignment region and a second region oriented in a second polarization direction, wherein the first region and the second region are arranged separately, and A polymerizable liquid crystal layer formed on a photo-alignment film, wherein the polymerizable liquid crystal layer is formed by applying the polymerizable liquid crystal in a plurality of times and performing UV irradiation; and The total thickness of the glass substrate, the light distribution film, and the polymerizable liquid crystal layer is formed to be 50 μm or less.

  An eighth aspect of the present invention is a region-dividing wavelength plate, which is a glass plate and a glass substrate attached on the glass plate, wherein the glass substrate is partially from the edge of the glass plate. A glass substrate attached in a protruding state, and a photo-alignment film applied on the glass substrate, wherein the photo-alignment film includes a first region oriented in a first polarization direction, and a second region A second region aligned in a polarization direction, the first region and the second region being arranged separately, and a photopolymerization film formed on the photoalignment film It is a liquid crystal layer, Comprising: The said polymeric liquid crystal layer is equipped with the polymeric liquid crystal layer formed by apply | coating a polymeric liquid crystal in multiple times and performing UV irradiation, It is characterized by the above-mentioned.

  A ninth aspect of the present invention is the area division wavelength plate according to the eighth aspect, wherein the total thickness of the glass substrate, the light hardening film, and the polymerizable liquid crystal layer is 50 μm or less. It is formed.

  A tenth aspect of the present invention is a region-divided wave plate, which is formed of a polymerizable liquid crystal layer, and the polymerizable liquid crystal layer is coated on a glass substrate, and has a low photo-alignment with the polymerizable liquid crystal. After being formed on the film, it is peeled off from the glass substrate, and the polymerizable liquid crystal layer is aligned in the first polarization direction and the second polarization direction, which are arranged in a divided manner. The first region oriented in the first polarization direction and the second region oriented in the second polarization direction are provided by being coated on the photo-alignment film having the second region formed. It is formed in this.

  An eleventh aspect of the present invention is the region division wavelength plate according to any one of the seventh to tenth aspects, wherein the photo-alignment film is covered with a striped mask, and is in the first polarization direction. UV direct polarized light is irradiated, and then the striped mask is shifted in the pitch direction so that the UV direct polarized light in the second polarization direction is applied to a region where the UV direct polarized light in the first direction is not irradiated. It is characterized by being oriented by being irradiated.

  According to the present invention, a thin region division wave plate of 50 μm or less can be realized. Therefore, when inserted into the optical waveguide, the polarization of each optical waveguide can be controlled, and it is not necessary to manually insert the wave plates one by one into the groove. Thus, the need for forming a wave plate in a comb shape by machining is eliminated.

It is a figure which shows a mode that a wavelength plate is inserted in the board | substrate with which the optical waveguide was formed. It is a top view which shows the waveguide type polarization beam splitter 200 which inserted two wavelength plates in one groove | channel. It is a perspective view which shows the polarizing beam splitter 300 which inserted the comb-tooth-shaped film-type wavelength plate. It is a figure which shows the process of the manufacturing method of the area | region division | segmentation wavelength plate concerning the 1st Embodiment of this invention. It is a figure which shows the relationship between the frequency | count of application | coating of the polymeric liquid crystal in the process of FIG. 4, and the phase difference of a wavelength plate. It is a figure which shows a mode that the wavelength plate produced in the process of FIG. 4 is inserted in an optical waveguide. It is a figure which shows the process of the manufacturing method of the area | region division | segmentation wavelength plate concerning the 2nd Embodiment of this invention. It is a figure which shows the process of the manufacturing method of the area | region division | segmentation wavelength plate concerning the 3rd Embodiment of this invention. It is a figure which shows the process of the manufacturing method of the area | region division | segmentation wavelength plate concerning the 4th Embodiment of this invention. It is a figure which shows the polarizing microscope photograph of the area | region division wavelength plate produced by the 1st Embodiment of this invention. It is a figure which shows a mode that the area | region division | segmentation wavelength plate of FIG. 10 was inserted in the optical waveguide groove | channel.

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

[First Embodiment]
FIG. 4 is a diagram illustrating the steps of the method of manufacturing the region-dividing wavelength plate according to the first embodiment of the present invention.

  First, in step 401, a glass substrate 411 having a thickness of about 1 mm is prepared, and a photo-alignment film 412 is applied to the glass substrate 411 by spin coating. The photo-alignment film is formed with a thickness of about 40 nm.

  In step 402, after the photo-alignment film 412 applied to the glass substrate 411 is dried and cured, the photo-alignment film 412 is irradiated with UV linearly polarized light to cause split light alignment. Divided light alignment is performed by using a metal mask 413 having a 250 μm stripe pitch, irradiating UV linearly polarized light in the 90 ° direction, and then moving the metal mask 413 250 μm in the pitch direction and irradiating the UV linearly polarized wave in the 0 ° direction. . Due to the split light alignment, a region having a polarization direction of 0 degrees and a region having a polarization direction of 0 degrees are arranged in a stripe shape on the light alignment film. The split light alignment can also be performed by rubbing alignment.

  In step 403, a polymerizable liquid crystal layer 414 is formed on the photo-alignment film 412 that has undergone split light alignment. Here, the polymerizable liquid crystal will be described. The polymerizable liquid crystal can be easily aligned by applying it on a normal liquid crystal alignment means (rubbed photo-alignment film or UV-irradiated photo-alignment film) in the monomer state, and the molecular arrangement of the liquid crystal skeleton in the aligned state. Can be fixed into a film by UV irradiation or the like (see Patent Documents 3 to 5).

  Unlike a normal side chain polymer liquid crystal, the polymerized liquid crystal does not show a liquid crystal phase and is a thermally stable cured product. Using these polymerizable liquid crystals, a phase difference film having a liquid crystal skeleton forming a homogeneous alignment, a super twist nematic (STN) alignment, or a pattern alignment, or a phase difference film having a different retardation depending on the place has been put into practical use. Yes. In particular, a stretched film has been conventionally used as a retardation compensation film for liquid crystal displays. However, a thinner, more easily polymerizable polymerizable liquid crystal retardation film has been put to practical use and patterned for 3D television. A retardation film has also been put into practical use.

  In addition, a polymerizable liquid crystal that does not require a photo-alignment film and that is aligned and polymerized in a direction orthogonal to the linearly polarized UV light, that is, a polymerizable liquid crystal having a function of a photo-alignment film is also available. is there. If this is used, it is not necessary to apply a photo-alignment film (see Non-Patent Documents 3 and 4).

  Next, details of step 403 will be described. First, a polymerizable liquid crystal containing a solvent is applied onto the photo-alignment film 412 by spin coating (1000 rpm), and the solvent is dried at 85 ° C. and allowed to cool. At the time of application, the polymerizable liquid crystal is aligned in a direction perpendicular to the photo-alignment direction of the photo-alignment film.

  The coated polymerizable liquid crystal is allowed to cool and then irradiated with UV to cure the polymerizable liquid crystal. Since the polymerizable liquid crystal has a thin film thickness of about 1 μm by one application, the polymerizable liquid crystal layer 414 is formed by performing overcoating and UV irradiation so as to obtain a desired thickness. In this embodiment, the coating is repeated until the film thickness of the polymerizable liquid crystal layer becomes 3 μm to 4 μm. Note that once the polymerizable liquid crystal is applied on the photo-alignment film 412, it is not necessary to apply the photo-alignment film on the polymerizable liquid crystal. Therefore, for the second and subsequent coatings of the polymerizable liquid crystal, it is only necessary to omit the photo-alignment film and the split photo-alignment and apply the polymerizable liquid crystal on the UV-irradiated polymerizable liquid crystal. This is because the polymerizable liquid crystal applied thereon inherits the alignment of the polymerizable liquid crystal. Here, FIG. 5 is a diagram showing the relationship between the number of coatings of the polymerizable liquid crystal and the retardation of the wave plate. As shown in FIG. 5, the number of times the polymerizable liquid crystal is applied and the retardation of the wave plate are in a linear relationship. The polymerizable liquid crystal layer 414 was well aligned without deterioration of alignment even when the polymerizable liquid crystal was applied five times or more. After forming the polymerizable liquid crystal phase 414, the glass substrate 411 is sufficiently annealed.

  In step 404, the glass substrate 411 is turned over, and the surface on which the polymerizable liquid crystal layer 414 is formed is attached to the polishing glass 415 with wax.

  In step 405, the polishing table (glass 415) to which the polymerizable liquid crystal layer 414 is attached is set in a glass polishing machine, and the total thickness of the polymerizable liquid crystal layer 414 + photo-alignment film 412 + glass substrate 411 reaches 15 μm. The glass substrate 411 is polished.

  In step 406, the glass substrate 411 polished to a desired thickness is cut into a desired size. Thereafter, the polishing table 415 is heated to melt the wax, and the cut region division wave plate 416 is peeled off and taken out. Thereafter, the area division wave plate 416 is washed with IPA. Thus, it is possible to realize a λ / 4 region-dividing wave plate having a thickness of 15 μm and having a region oriented in the 90 ° and 0 ° directions in a stripe shape with a 250 μm bitch.

  FIG. 6 is a diagram illustrating a state in which the wave plate 406 created in the process of FIG. 4 is inserted into the optical waveguide. The region division wavelength plate 406 is inserted into a groove 603 having a width of 20 μm and a depth of 150 μm formed so as to cross the optical waveguide 602 formed on the Si substrate 601 by vacuum tweezers. The polarization could be rotated 90 ° for every 250 μm pitch. The extinction ratio was 20 dB.

[Second Embodiment]
FIG. 7 is a diagram showing the steps of the method of manufacturing the region-dividing wavelength plate according to the second embodiment of the present invention. First, in step 701, a glass substrate 711 is prepared, and a photo-alignment film 712 is applied to the glass substrate 711 by spin coating. In step 702, after drying and curing the photo-alignment film 712 applied to the glass substrate 711, using a metal mask 713 having a 250 μm stripe pitch, the photo-alignment film 712 is irradiated with UV linearly polarized waves in a 90-degree direction, and then the metal mask. 713 is moved by 250 μm in the pitch direction, and UV linearly polarized light is irradiated to the photo-alignment film 712 in the 0-degree direction to perform split light alignment.

  In Step 703, a polymerizable liquid crystal layer 714 is formed on the photo-alignment film 712 that has undergone split light alignment. First, a polymerizable liquid crystal containing a solvent is applied by spin coating (1000 rpm). In the present embodiment, the photo-alignment film and the polymerizable liquid crystal are selected as a combination having weak adhesion. The applied polymerizable liquid crystal is dried at 85 ° C. and allowed to cool. The coated polymerizable liquid crystal is allowed to cool and then irradiated with UV to cure the coated polymerizable liquid crystal. The polymerizable liquid crystal is further overcoated so as to have a desired thickness, and UV irradiation is performed to form a polymerizable liquid crystal layer 714. After forming the polymerizable liquid crystal layer 714, the glass substrate is sufficiently annealed.

  In step 704, the polymerizable liquid crystal layer 714 can be peeled off as a thin film 716 by applying an adhesive tape 715 to the end of the formed polymerizable liquid crystal layer 714 and pulling it. When the peeled film 716 is cut into a desired size, an area division wavelength plate 717 is obtained.

  The region division wavelength plate 717 has a thickness of about 10 μm, and when inserted into the optical waveguide, is formed so as to cross the optical waveguide formed on the Si substrate by vacuum tweezers as in the first embodiment. Insert into the groove.

[Third Embodiment]
FIG. 8 is a diagram showing the steps of the method for manufacturing the region-dividing wavelength plate according to the third embodiment of the present invention. First, in Step 801, a thin glass substrate 811 having a thickness of 10 μm is attached to the glass plate 812. When the glass substrate 811 is attached to the glass plate 812, the glass substrate 811 is attached so as to protrude from the glass plate 812 by 30 μm or more as shown in FIG. The reason why the thickness is 30 μm is that the core of the optical waveguide is usually formed at a position of about 30 μm from the surface. A photo-alignment film 813 is applied to the glass substrate 811 by spin coating. In step 802, after drying and curing the photo-alignment film 813 applied to the glass substrate 811, using a metal mask 814 with a 250 μm stripe pitch, the photo-alignment film 813 is irradiated with UV linearly polarized light in a 90-degree direction, and then the metal mask. The optical alignment film 813 is irradiated with UV linearly polarized light in the 0 degree direction by moving 814 in the pitch direction by 250 μm, and split light alignment is performed.

  In step 803, a polymerizable liquid crystal layer 815 is formed on the photo-alignment film 813 that has been subjected to split light alignment. First, a polymerizable liquid crystal containing a solvent is applied on the photo-alignment film 813 by spin coating (1000 rpm). The applied polymerizable liquid crystal is dried at 85 ° C. and allowed to cool. The coated polymerizable liquid crystal is allowed to cool and then irradiated with UV to cure the coated polymerizable liquid crystal. The polymerizable liquid crystal is further overcoated so as to have a desired thickness, and UV irradiation is performed to form a polysynthetic liquid crystal layer 815. After forming the polymerizable liquid crystal layer 815, the glass substrate is sufficiently annealed.

  In Step 804, the region division wavelength plate (glass substrate 811 + photo-alignment film 813 + polymerizable liquid crystal layer 815) attached to the glass plate 812 is placed on the optical waveguide 816. Specifically, the glass plate 812 and the glass substrate 811 are placed so that part of the protrusions is in contact with the upper surface of the optical circuit. At this time, since the 10 μm glass substrate 811 protrudes from the glass plate 812, the glass substrate 811 is slightly inclined. In this state, the glass plate 812 is slid to the groove 817 of the optical waveguide 816. When reaching the groove 817, the wave plate portion protruding from the glass plate 812 is inserted into the groove 817 of the optical waveguide 816 (step 805). .

  By projecting and adhering the glass substrate 811 to the glass plate 812, a region-dividing wavelength plate of several tens of μm is inserted into the groove 817 of the optical waveguide 816 without directly handling the 10 μm glass substrate 811. Can do.

[Fourth Embodiment]
FIG. 9 is a diagram illustrating the steps of the method for manufacturing the region-dividing wavelength plate according to the fourth embodiment of the present invention. First, in step 901, a glass plate 911 is prepared, and a thin glass substrate 912 having a thickness of 10 μm is attached to the glass plate 911 using a wax 913. Alternatively, four corners of a thin glass substrate 912 having a thickness of 10 μm are fixed on the glass plate 911 using an adhesive 914. In step 902, a photo-alignment film 915 is applied to the glass substrate 912 by spin coating. In step 903, after drying and curing the photo-alignment film 915 applied to the glass substrate 912, using a metal mask 916 having a 250 μm stripe pitch, the photo-alignment film 915 is irradiated with UV linearly polarized waves in a 90-degree direction, and then the metal mask. The optical alignment film 914 is irradiated with UV linearly polarized light in the 0-degree direction by moving 916 by 250 μm in the pitch direction, and split light alignment is performed.

  In step 904, a polymerizable liquid crystal layer 917 is formed on the photo-alignment film 915 that has been subjected to split light alignment. First, a polymerizable liquid crystal containing a solvent is applied on the photo-alignment film 915 by spin coating (1000 rpm). The applied polymerizable liquid crystal is dried at 85 ° C. and allowed to cool. The coated polymerizable liquid crystal is allowed to cool and then irradiated with UV to cure the coated polymerizable liquid crystal. The polymerizable liquid crystal is further overcoated so as to have a desired thickness, and UV irradiation is performed to form a polymerizable liquid crystal layer 917. After forming the polymerizable liquid crystal layer 917, the glass substrate is sufficiently annealed.

  In step 905, the glass substrate 912 having a thickness of 10 μm on which the photo-alignment film 915 and the polymerizable crystal layer 917 are formed is cut into a desired size.

  In step 906, the wax bonding the glass plate 911 and the glass substrate 912 is heated and melted, or the adhesive is removed, and the cut region division wave plate 918 is taken out. Thereafter, the area division wave plate 918 is washed with IPA. The cleaned region division wave plate 918 is inserted into a groove on the optical circuit using vacuum tweezers or the like.

[Example]
FIG. 10 is a diagram showing a state of a polarization micrograph of a 250 μm pitch λ / 4 region-dividing wave plate oriented in the ± 45 ° direction and manufactured according to the first embodiment of the present invention. FIG. It is a figure which shows a mode that the 250 micrometer pitch (lambda) / 4 area division | segmentation wavelength plate was inserted in the optical waveguide groove | channel.

  Also, the input light is separated into TE and TM polarized waves by the PBS array, and inserted into the optical waveguides that are TE, TM, TE, TM, TE, and TM in the direction of the optical waveguide array. Are aligned with TE or TM polarization, a λ / 2 region division wave plate with a pitch of 250 μm oriented in the direction of 0 ° and 45 ° was prepared and inserted into the optical waveguide array. As a result, all polarized waves could be aligned with TE or TM polarized waves.

101, 201, 301, 601 Si substrate 102, 202, 204, 205, 207, 208, 302a to 302h, 602 Optical waveguide 103, 816 Optical circuit 104, 212, 603, 817 Groove 105, 212, 213, 303 Wave plate 203 Y branch coupler 206 2 × 2 MMI
411, 711, 811, 912 Glass substrate 412, 712, 813, 915 Photo-alignment film 413, 713, 916 Striped metal mask 414, 714, 815, 917 Polymerizable liquid crystal layer 415 Polishing table 416, 406, 717, 918 Region Division wavelength plate 715 Tape 716 Film 812, 911 Glass plate 913 Wax 914 Adhesive

Claims (11)

Applying a photo-alignment film on a glass substrate;
Orienting a first region of the photo-alignment film in a first polarization direction and orienting a second region of the photo-alignment film in a second polarization direction, the first region and the first Steps arranged separately from the area of 2;
Applying a polymerizable liquid crystal on the photo-alignment film;
Irradiating the polymerizable liquid crystal with UV;
Applying a polymerizable liquid crystal on the polymerizable liquid crystal and performing UV irradiation to form a polymerizable liquid crystal layer;
Bonding the surface of the glass substrate coated with the photo-alignment film to a polishing table, and polishing the surface of the glass substrate opposite to the surface coated with the photo-alignment film to a desired thickness;
Cutting the glass substrate into a desired size, and peeling the glass substrate from the polishing table. A step of affixing a glass substrate on a glass plate, wherein the glass substrate is affixed in a state in which a part protrudes from an edge of the glass plate; and
Applying a photo-alignment film on the glass substrate;
Orienting a first region of the photo-alignment film in a first polarization direction and orienting a second region of the photo-alignment film in a second polarization direction, the first region and the first Steps arranged separately from the area of 2;
Applying a polymerizable liquid crystal on the photo-alignment film;
Irradiating the polymerizable liquid crystal with UV;
Applying a polymerizable liquid crystal on the polymerizable liquid crystal and performing UV irradiation to form a polymerizable liquid crystal layer;
And inserting a portion of the glass substrate protruding from the glass plate into a groove formed on the optical circuit so as to cross the optical waveguide. Attaching a glass substrate on the glass plate;
Applying a photo-alignment film on the glass substrate;
Orienting a first region of the photo-alignment film in a first polarization direction and orienting a second region of the photo-alignment film in a second polarization direction, the first region and the first Steps arranged separately from the area of 2;
Applying a polymerizable liquid crystal on the photo-alignment film;
Irradiating the polymerizable liquid crystal with UV;
Applying a polymerizable liquid crystal on the polymerizable liquid crystal and performing UV irradiation to form a polymerizable liquid crystal layer;
Cutting the glass substrate into a desired size, and peeling the glass substrate from the glass plate.   4. The region according to claim 1, wherein a total thickness of the glass substrate, the light distribution film, and the polymerizable liquid crystal layer is formed to be 50 μm or less. 5. A method of manufacturing a divided wave plate. Applying a photo-alignment film on a glass substrate;
Orienting a first region of the photo-alignment film in a first polarization direction and orienting a second region of the photo-alignment film in a second polarization direction, the first region and the first Steps arranged separately from the area of 2;
A step of applying a polymerizable liquid crystal on the photo-alignment film, wherein the photo-alignment film and the polymerizable liquid crystal are weak in adhesion; and
Irradiating the polymerizable liquid crystal with UV;
Applying a polymerizable liquid crystal on the polymerizable liquid crystal and performing UV irradiation to form a polymerizable liquid crystal layer;
Peeling the polymerizable liquid crystal layer from the glass substrate. A method for producing a region-dividing wavelength plate, comprising: Orienting the first region of the photo-alignment film in a first polarization direction and orienting the second region of the photo-alignment film in a second polarization direction,
Covering the photo-alignment film with a striped mask and irradiating UV directly polarized light in the first polarization direction;
Displacing the stripe-shaped mask in the pitch direction, and irradiating the UV polarized light in the second polarization direction to a region not irradiated with the UV direct polarization in the first direction. The manufacturing method of the area | region division | segmentation wavelength plate of any one of Claim 1 thru | or 4 characterized by the above-mentioned. A glass substrate;
A photo-alignment film coated on the glass substrate, the photo-alignment film comprising: a first region oriented in a first polarization direction; a second region oriented in a second polarization direction; A photo-alignment film, wherein the first region and the second region are arranged separately, and
A polymerizable liquid crystal layer formed on the photo-alignment film, wherein the polymerizable liquid crystal layer is formed by applying the polymerizable liquid crystal in a plurality of times and performing UV irradiation. When,
And a total thickness of the glass substrate, the light distribution film, and the polymerizable liquid crystal layer is formed to be 50 μm or less. A glass plate,
A glass substrate affixed on the glass plate, wherein the glass substrate is affixed with a part protruding from an edge of the glass plate; and
A photo-alignment film coated on the glass substrate, the photo-alignment film comprising: a first region oriented in a first polarization direction; a second region oriented in a second polarization direction; A photo-alignment film, wherein the first region and the second region are arranged separately, and
A polymerizable liquid crystal layer formed on the photo-alignment film, wherein the polymerizable liquid crystal layer is formed by applying the polymerizable liquid crystal in a plurality of times and performing UV irradiation. When,
A region-dividing wavelength plate comprising:   9. The region division wavelength plate according to claim 8, wherein a total thickness of the glass substrate, the light distribution film, and the polymerizable liquid crystal layer is formed to be 50 μm or less. A region-dividing wave plate formed by a polymerizable liquid crystal layer,
The polymerizable liquid crystal layer is applied on a glass substrate, formed on a photo-alignment film having low adhesion to the polymerizable liquid crystal, and then peeled off from the glass substrate.
The polymerizable liquid crystal layer is applied on the photo-alignment film including a first region oriented in a first polarization direction and a second region oriented in a second polarization direction arranged in a divided manner. Thus, the region-dividing wavelength plate is formed so as to include a first region oriented in the first polarization direction and a second region oriented in the second polarization direction.   The photo-alignment film is covered with a striped mask and irradiated with UV direct polarization in the first polarization direction, and then the UV mask in the first direction is shifted by shifting the striped mask in the pitch direction. 11. The region division according to claim 7, wherein the region division is performed by irradiating the UV direct polarization in the second polarization direction to a region where the polarization is not irradiated. Wave plate.

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