JP2007193008A - Multilayer waveguide and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer waveguide including a photosensitive medium having small loss, and to provide its manufacturing method. <P>SOLUTION: The multilayer waveguide has a multilayer structure laminated so as to alternately superpose a polymer clad layer (set in thickness d<SB>0</SB>, and refractive index n<SB>0</SB>) and a polymer core layer (thickness d<SB>1</SB>and refractive index n<SB>1</SB>, in addition, set in n<SB>1</SB>>n<SB>0</SB>), sets 10dB/cm or less of guiding light loss, forms a light introduction part introducing light on an end face extending along an orthogonal direction or a direction of 45 degrees to a direction of a laminated layer extension, contains the photosensitive medium, sets Δn=n<SB>1</SB>-n<SB>0</SB>by a refractive index Δn of the clad layer and the core layer, and when the light of wavelength λ<SB>1</SB>is propagated, d<SB>0</SB>, d<SB>1</SB>, and Δn are set so as to satisfy inequality 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multilayer waveguide having a multilayer structure in which clad layer / core layer / cladding layer / core layer / cladding layer.

Conventionally, multilayer waveguides have been used as multilayer structure type optical hologram memories. Many patent applications have been filed for this type of optical hologram memory (see, for example, Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5).
JP 2004-109871 A JP 2001-092339 A JP 2000-321964 A JP 2002-366017 A JP 11-337756 A

  This type of multi-layer structure type optical hologram memory is configured exclusively for reading. This structure and reading method are as shown in FIG. 9, for example. That is, reference numeral 101 denotes a multilayer hologram medium, and this multilayer hologram medium 101 is laminated so that the clad layer 103 and the core layer 102 are alternately overlapped to form a multilayer structure. The thickness of the cladding layer 103 is 10 to 20 μm, and the thickness of the core layer 102 is 0.5 to 1 μm. Reference numeral 104 denotes a computer generated hologram, which is constituted by unevenness provided between the cladding layer 103 and the core layer 102. Reference numeral 105 indicates readout light, reference numeral 106 indicates a cylindrical lens, reference numeral 107 indicates diffracted light, and reference numeral 108 indicates an image sensor that reads two-dimensional information.

  In the multilayer hologram medium 101 configured as described above, the reading light 105 is incident on the side end surface of the selected layer of the multilayer hologram medium 101. The reading light 105 that has entered the light propagates through the multilayer hologram medium 101 and is diffracted by the computer generated hologram 104 that is configured to be uneven. Then, the diffracted light 107 is read out by a two-dimensional information reading image sensor 108 disposed so as to face the multilayer hologram medium 101. The multilayer hologram medium 101 configured in this way has a multilayer structure composed of a clad layer and a core layer, so that a large-capacity storage medium can be realized while being compact. .

  The read-only multilayer hologram memory 101 is manufactured as shown in the manufacturing process diagram of FIG. That is, as shown in FIG. 10A, the clad layer 112 and the core layer 113 are laminated on the film substrate 111. The clad layer 112 and the core layer 113 are made of an ultraviolet curable resin. Reference numeral 114 denotes a stamper on which a computer generated hologram to be laminated on the core layer 113 is written, and an ultraviolet curable resin paint is applied on the stamper. Next, as shown in FIG. 10B, the clad layer 112 and the core layer 113 laminated in this way are irradiated with ultraviolet rays 115 and cured so that the laminated layers are fixed to the film substrate 111. Then, as shown in FIG. 10C, the stamper 114 is peeled off.

  Thereafter, a new cladding layer and a core layer are laminated on the laminate shown in FIG. 10C so that the procedure shown in FIGS. 10A and 10B is repeated. That is, as shown in FIG. 10D, a new low-refractive clad 116 layer and a new core layer 117 are laminated on the laminate shown in FIG. However, as shown in FIG. 10E, the ultraviolet rays 115 are irradiated to cure these laminates so as to adhere to the laminate of FIG. 10C. Then, as shown in FIG. 10F, the stamper 114 is peeled off.

  As described above, by repeating the steps from FIG. 10A to FIG. 10E, the multilayer hologram medium 101 described above is manufactured to realize the manufacture of the multilayer structure type optical hologram memory. Since the multilayer optical hologram memory is manufactured as a read-only memory in this way, an ultraviolet curable resin cladding layer or an ultraviolet curable resin core layer is used because of the ease of manufacturing the multilayer structure. It was.

  By the way, there is a demand to make the above-described multilayer structure type optical hologram memory writable or rewritable. When a multi-layer structure type optical hologram memory is configured to be writable or rewritable as described above, a change in refractive index is caused by light of two wavelengths. Two-photon absorption or two-color absorption It was necessary to dope a photosensitive medium such as.

  However, such a photosensitive medium has a property that the photosensitive medium itself is exposed when irradiated with ultraviolet rays. In such a production method as described above, the photosensitive medium is cured by irradiation with ultraviolet rays. It was left unwell to use. In addition, photosensitive media such as two-photon absorption or two-color absorption have a property of absorbing a large amount of light, and there remains a problem that a waveguide doped with this has a very large loss. It was. In addition, when preparing a layered film usually made of a polymer, if the film is to be laminated by spin coating or blade method, the solvent of the film applied above is applied to the underlying layer. There is also a problem (intermixing) in which the membranes are mixed and the membranes are mixed.

  On the other hand, development of a multilayer optical memory in which a layer containing a two-photon absorption medium is sandwiched between adhesive layers is also progressing. In the case of a multilayer optical memory including such a two-photon absorption medium, the light from the multilayer optical memory is focused on a selected layer by injecting an ultrashort pulse laser beam perpendicular to the plane. Only by using the two-photon absorption effect selectively, pits (points where the refractive index, reflectance, and transmittance are changed) can be written. As a result, a large-capacity memory can be realized. Note that the multilayer hologram memory configured without using the waveguide structure used in the multilayer optical memory has a characteristic that light is not propagated in parallel to the layers.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a multilayer waveguide including a photosensitive medium with little loss and a manufacturing method thereof. In particular, in a multi-layer optical memory, light of λ ₁ can be propagated only to a selected layer, light of λ ₂ can be applied perpendicularly to the layer, and information can be written only at the point where the light of λ ₁ and λ ₂ intersect An object of the present invention is to provide a structure of an optical memory having a multi-layer waveguide structure and a manufacturing method thereof.

  In order to solve the above-described problems, the present invention provides the following multilayer waveguide and a method for manufacturing the same as the means. That is, in a structure and manufacturing method of a multilayer waveguide memory, etc., a photosensitive medium such as two-photon absorption or two-color absorption is doped only in a cladding layer where light does not propagate, and heat softening is performed instead of an ultraviolet curable resin. Provided is a method for producing a multilayer waveguide formed by laminating layers containing a photosensitive medium by bonding polymer layers of a mold together by heat lamination, heat press pressure bonding, or heat roll pressure bonding. In addition, the polymer layers are laminated by thermosetting transparent adhesive, laminated, press-bonded, or roll-bonded to be multilayered, and then thermally bonded together to include a photosensitive medium. The present invention provides a method for producing a multilayer waveguide obtained by stacking layers. More specifically, it is as follows.

That is, the multilayer waveguide according to claim 1 includes a polymer cladding layer (set to a thickness d ₀ and a refractive index n ₀ ) and a polymer core layer (thickness d ₁ and a refractive index n ₁ (where n ₁ > n ₀ )) are alternately stacked, the loss of guided light is set to 10 dB / cm or less, and the light introduction part is used to introduce light. The laminated layer is formed with an end face extending in a direction orthogonal to the extending direction or a direction of 45 degrees, and the clad layer contains a photosensitive medium.

The multilayer waveguide according to claim 2 is the multilayer waveguide according to claim 1, wherein the refractive index difference Δn between the cladding layer and the core layer is set to Δn = n ₁ −n ₀ When propagating light of λ ₁

を満たすように、ｄ_０、ｄ_１、Δｎが設定されていることを特徴とする。

D ₀ , d ₁ , and Δn are set so as to satisfy the above.

A multilayer waveguide according to claim 3 is the multilayer waveguide according to claim 1 or 2, wherein the photosensitive medium is pentathiophene.
A multilayer waveguide according to a fourth aspect is the multilayer waveguide according to any one of the first to third aspects, wherein the multilayer waveguide has a hologram memory function.

  According to a fifth aspect of the present invention, there is provided a multilayer waveguide manufacturing method in which either a clad or a core film is coated on a first film by any one of a spin coating method, a blade method, and screen printing. Then, the first film is laminated on the newly prepared second film so that the first laminating film is sandwiched between the first laminating film and the first laminating film. After bonding by either the pressure bonding method or the hot roll pressure bonding method, the first film is peeled off from the second film, and the first lamination film is removed from the first film. A clad layer or a core layer is formed on the second film so as to be transferred to a film, and then a spin coating method, a blade method, or screen printing is performed on the first film. Accordingly, the second lamination film is formed by coating either the clad or the core film different from the first lamination film, and removing the solvent to form the second lamination film. Is bonded to the clad layer or the core layer formed on the second film, and the first film is bonded to the second film by any one of a heat laminating method, a hot press pressing method, and a hot roll pressing method. The first film is peeled off from the second film, and the second lamination film is transferred from the first film to the second film. By laminating a new clad layer or core layer different from the clad layer or core layer formed on the film 2 and repeating such a laminating procedure, Forming a multilayer part laminated on the second film so that a clad layer and a core layer are alternately superposed, and orthogonal to a direction in which the laminated layer extends in the multilayer part; It is cut out in a direction or a direction of 45 degrees to form an end face serving as a light introducing portion.

  According to a sixth aspect of the present invention, there is provided a multilayer waveguide manufacturing method in which one of a clad film and a core film is coated on a first film by any one of a spin coating method, a blade method, and screen printing. The solvent is removed to form the first lamination film, and the second film is different from the first lamination film by spin coating, blade method, or screen printing on the second film. The other film of the core is coated and the solvent is removed to form a second laminated film, and the first and second laminated films are made to face each other, and the thermosetting property is set between them. The first film and the second film are bonded together by any one of a laminating method, a press-bonding method, and a roll-bonding method while interposing a transparent adhesive having the second film. The first film is peeled off, and the first film for lamination is transferred from the first film to the second film, so that a clad layer and a core layer are formed on the second film. Then, it differs from the clad layer or the core layer formed on the uppermost surface of the second film on the first film by any one of a spin coating method, a blade method, and screen printing. Then, the clad or core film is applied and the solvent is removed to form a new lamination film, and this new lamination film is formed on the uppermost surface of the second film. The first film and the second film are laminated while interposing a transparent adhesive having a thermosetting property therebetween so as to face the layer or the core layer, The first film is peeled off from the second film, and the first film for laminating is transferred from the first film to the second film. Then, a new clad layer or core layer is laminated on the clad layer or core layer that has been formed, and the laminating procedure is repeated, whereby the clad layer and the core layer are formed on the second film. Are formed so as to be alternately stacked to form a multi-layered part, and the multi-layered part or single-layer part thus formed is subjected to thermocompression bonding at once or for every multi-layered part. An end face serving as a light introducing portion is formed by cutting in a direction orthogonal to a direction in which the stacked layers extend or a direction of 45 degrees.

A multilayer waveguide manufacturing method according to claim 7 is the multilayer waveguide manufacturing method according to claim 6, wherein the adhesive is a two-component thermosetting silicone resin.
Further, according to an eighth aspect of the present invention, there is provided a multilayer waveguide fabrication method according to any one of the fifth to seventh aspects, wherein the cladding film is a fluorinated polymethyl methacrylate (fluorine). The core layer is formed of polymethylmethacrylate, and the temperature at the time of thermocompression bonding is 100 to 150 ° C. The conversion rate is set to 1 to 5% by weight and the refractive index is set to n ₁ > n ₀ ). It is characterized by being set to.
A multilayer waveguide fabrication method according to claim 9 is the multilayer waveguide fabrication method according to any one of claims 5 to 7, wherein the cladding film and the core film are cycloolefins. It is formed of a polymer (refractive index is set to n ₁ > n ₀ ), and the temperature at the time of thermocompression bonding is set to 150 to 180 ° C.
A method for producing a multilayer waveguide according to claim 10 is the method for producing a multilayer waveguide according to any one of claims 5 to 9, wherein the first film is a polyethylene terephthalate film. It is characterized by being.
A multilayer waveguide fabrication method according to claim 11 is the multilayer waveguide fabrication method according to any one of claims 5 to 9, wherein the core film is formed on the first film. After that, a mask is placed on the substrate, and the refractive index of the irradiated portion is changed by ultraviolet irradiation, laser irradiation, or ion implantation.

  According to the multilayer waveguide and the manufacturing method thereof according to the present invention, (1) loss can be reduced while being a multilayer waveguide including a photosensitive medium such as photosensitive two-photon absorption and two-color absorption. (2) The photosensitive medium can be multilayered without being exposed to light, and (3) there is an advantage that no intermixing problem occurs even when the multilayer is formed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a multilayer waveguide according to the invention will be described with reference to the drawings. In the multilayer waveguide described below and the manufacturing method thereof, there is no problem even if the guided light is either single mode or multimode. However, in view of writing on the hologram, it is desirable to select the single mode. In manufacturing a multilayer waveguide by this single mode, the following refractive index control and film thickness control are required.

That is, reference numeral 1 in FIG. 1 shows a cross-sectional view of the multilayer waveguide according to the present invention. The multi-layer waveguide 1 has a multi-layer structure in which a clad layer 10 and a core layer 20 are laminated so as to alternately overlap each other. In addition, this layer is formed in a film shape, and may be referred to as a film below. FIG. 2 is a partially enlarged view of FIG. 1, showing two clad layers 10 and a core layer 20 located between them. Both the clad layer 10 and the core layer 20 are made of a polymer. Here, the thickness d ₀ and the refractive index n ₀ are set for the cladding layer 10, and the thickness d ₁ and the refractive index n ₁ are set for the core layer 20. Reference numeral lambda _C in Figure 2 shows the wavelength of the propagated the laminated cladding layer 10 and core layer 20 light. In the multilayer waveguide 1 set as described above, the propagation condition of the single mode is set as follows.

The wavelength λ _C of the light propagating to the multilayer waveguide 1 is set as shown in [Equation 2]. Regarding V _C , a, and δ used in this [Equation 2], [Equation 3] is set. Therefore, when [Equation 3] is substituted for [Equation 2], [Equation 4] is obtained. Note that Δn = n ₁ −n ₀ .
Here, the refractive index n ₀ of the clad layer _10, the respective refractive index n ₁ of the core layer 20, and takes a value of nearly "1.5", if approximating the sum of about "3", above [Equation 5] can be obtained from [Equation 4].

In the [Equation 5] obtained in this way, for example, when the wavelength λ _C of the propagated light is set to 0.66 μm and the thickness of the core layer 20 is set to 5 μm, the single mode for this multilayer waveguide 1 is set. The condition is Δn <1.45 × 10 ⁻³ , and the clad layer 10 and the core layer 20 constituting the multilayer waveguide 1 must be adjusted with an accuracy of “10 ⁻³ ”. On the other hand, for example, when the wavelength λ _C of the propagated light is set to 0.66 μm and the thickness of the core layer 20 is set to 1 μm, the single mode condition for the multilayer waveguide 1 is Δn <0.0364, The clad layer 10 and the core layer 20 constituting the multilayer waveguide 1 need only be adjusted with an accuracy of “10 ⁻² ”, and there is an advantage that requirements for accuracy adjustment are eased. Although not specifically shown in the figure, this multilayer waveguide 1 has an end surface extending in a direction orthogonal to the direction in which the layer in which the light introduction part is laminated for introducing light extends or in a direction of 45 degrees. The clad layer 10 contains a photosensitive medium.

  Next, a basic manufacturing process for the multilayer waveguide 1 configured as described above will be described with reference to FIG. That is, reference numeral 31 is a first film, reference numeral 32 is a second film, reference numeral 33 is a clad film (first laminating film) formed by coating and drying, and reference numeral 34 is applied and dried. A core film (second laminating film) is formed, and reference numeral 35 denotes a roll laminator (a heat laminating method is adopted). The clad film 33 and the core film 34 are formed on the first film 31. When the clad film 33 and the core film 34 are formed on the first film 31, they are in a film state. The clad film 33 and the core film 34 are formed.

  First, in FIG. 3 (a), this is applied to the first film 31 on which the clad film 33 is formed by coating the clad and removing the solvent by spin coating, blade or screen printing. The first film 31 is bonded to a newly prepared second film 32 by a roll laminator 35 so as to sandwich the clad film 33. Then, after bonding the first film 31 and the second film 32, the first film 31 is peeled off from the second film 32. At this time, the clad layer 33 </ b> A is formed on the second film 32 so that the clad film 33 is transferred from the first film 31 to the second film 32.

  Next, as shown in FIG. 3B, the first film in which the core film 34 is formed by coating the core and removing the solvent again by any one of the spin coating method, the blade method, and the screen printing. The first film 31 is bonded to the second film 32 by a roll laminator 35 so that the core film 34 is bonded to the clad layer 33 </ b> A formed on the second film 32. Then, after bonding the first film 31 and the second film 32, the first film 31 is peeled off from the second film 32. At this time, the core layer 34 A is formed on the second film 32 so that the core film 34 is transferred from the first film 31 to the second film 32. That is, the clad layer 33A is laminated so that a new core layer 34A different from this overlaps. In addition, it is preferable to use a polyethylene terephthalate (PET) film for the first film 31 from the viewpoint of easy peeling of the formed film.

  By repeating such a lamination procedure, a multilayer portion 1A is formed in which the clad layers 33A and the core layers 34A are alternately laminated on the second film 32 as shown in FIG. . The multi-layer portion 1A has a multi-layer structure, and although not particularly illustrated, the multi-layer portion 1A has a direction orthogonal to the direction in which the stacked layers 33A and 34A extend or An end face serving as a light introducing portion is formed by cutting in a 45 degree direction.

  Even if the clad layer 33A and the core layer 34A are interchanged and stacked alternately, it is assumed that there is no problem. Moreover, in the above-mentioned, it is an example of thermocompression bonding by a heat laminating method using a roll laminator 35, but is not limited thereto, and an appropriate press crimping machine (thermal press crimping method) or roll crimping machine ( The first film 31 and the second film 32 may be bonded together by a hot roll pressing method).

  Next, another example of the basic fabrication process for the multilayer waveguide 1 will be described with reference to FIG. That is, reference numeral 41 is a first film, reference numeral 42 is a second film, reference numeral 43 is a cladding layer (second laminating film defined in claim 5), and reference numeral 44 is a core layer. The adhesive layer is a first laminating film as defined in claim 5, and reference numeral 45 is a roll laminator (a heat laminating method is employed). The adhesive layer 44 is formed by applying a thermosetting transparent adhesive (for example, silicone resin) to the second film 42 by any one of a spin coating method, a blade method, and a screen method. ing.

  In FIG. 4, a clad layer 43 is previously formed on the first film 41 by any one of a spin coating method, a blade method, and screen printing. Then, an adhesive layer 44 is formed on the clad layer 43 formed on the first film 41 by using a transparent adhesive serving as a thermosetting resin by any one of a spin coating method, a blade method, and screen printing. To do. The adhesive layer 44 constitutes the core layer 44 as described above.

  Next, the first and second film-formed layers are opposed to the second film 42 on which the clad layer 43 is formed in advance by any one of a spin coating method, a blade method, and screen printing. The first film 41 is bonded to the second film 42 by the roll laminator 45 so as to match. Then, after bonding the first film 41 and the second film 42, the first film 41 is peeled off from the second film 42. At this time, a new cladding layer 43 is formed on the second film 42 so that the previously formed cladding layer 43 is transferred from the first film 41 to the second film 42. That is, the clad layer 43 and the clad layer 43 are laminated so that a different core layer 44 </ b> A, which is an adhesive layer 44, overlaps with the clad layer 43. In addition, it is preferable to use a polyethylene terephthalate (PET) film for the first film 31 as in the above-described basic manufacturing process.

  By repeating such a laminating procedure, the multilayer portion 1A is laminated such that the clad layer 43 and the core layer 44A are alternately superposed on the first or second film 41, 42 as shown in FIG. Will be formed. The multi-layer portion 1A has a multi-layer structure, and although not particularly illustrated, the multi-layer portion 1A is orthogonal to the direction in which the stacked layers 43A and 44A extend or An end face serving as a light introducing portion is formed by cutting in a 45 degree direction. The second film 42 is preferably a film made of the same material as that used for the clad layer 43 and the core layer 44 </ b> A (adhesive layer 44) from the viewpoint of adhesiveness of the clad layer 43. In this way, by repeating the lamination transfer of the cladding layer 43 and the like on the first film 41, the layers (films) can be multilayered so as to be laminated.

[Example 1]
Next, specific examples performed based on the two basic manufacturing steps described above will be described.
FIG. 5 shows the steps of Example 1 according to the present invention (an example in which a multi-layer portion is formed by ZEONEX 480R / ZEONEX E48R / ZEONEX 480R /...). ZEONEX 480R (refractive index n ₀ = 1.525 at 589 nm) and ZEONEX E48R (refractive index n ₁ = 1.530 at 589 nm) which are cycloolefin polymers of Nippon Zeon Co., Ltd. are alternately layered as a cladding layer and a core layer, respectively. It shows the process of going.

Reference numeral 51 denotes a PET film having a thickness of 250 μm, which is flexible but has a hardness that allows a film to be spin-coated thereon. Reference numeral 52 is a ZEONOR of Nippon Zeon Co., Ltd., a film made of ZEONEX, reference numeral 53 is ZEONEX 480R, reference numeral 54 is ZEONEX E48R, and reference numeral 55 is a thermal roll laminator. ZEONEX 480R and ZEONEX E48R are dissolved in mesitylene in an amount of 5 to 30% by weight to form a solution. To the ZEONEX 480R solution as the cladding layer, pentathiophene (refractive index n = 1.602 at 633 nm) as the photosensitive medium (two-color absorption medium) and DZDS (trade name of Azide, manufactured by Toyo Gosei Co., Ltd. as the energy acceptor, (Refractive index n = 1.585 at 633 nm) is added in an amount of 1 to 10% by weight. The absorption coefficient of this layer has a value at 410 nm of 340 cm ⁻¹ , and when used for the core layer, the absorption coefficient is attenuated to 1/100 only by 100 μm. On the other hand, when the one including the two-color absorbing medium is used as the clad, the main light propagates through the core layer, and the leaked light sensitizes the clad photosensitive medium. The light is advantageous because it only attenuates to about 1/10.

  These solutions are formed in a dark room or a yellow room on a film made of PET by a spin coating method and dried at a temperature of 90 ° C. The ZEONEX 480R as the cladding is applied with a thickness of 10 to 20 μm, and the ZEONEX E48E as the core is applied with a thickness of 1 to 5 μm. Here, although the refractive index difference (Δn) between the clad and the core varies depending on the concentrations of pentathiophene and DZDS, the following single-mode conditions obtained above are satisfied.

Here, the wavelength λ ₁ is the second excitation light of pentathiophene, and the wavelength is 650 nm. The wavelength of the first excitation light of pentathiophene is 410 nm, and the absorption is large at this wavelength. For this reason, ZEONEX E48R, which is a core layer through which light propagates, is doped with ZEONEX 480R that constitutes the cladding layer without doping pentathiophene. The light is not completely confined in the core layer but also oozes out into the clad layer, and is recorded in pentathiophene using this leaching light.

  First, ZEONEX 480R (10 to 20 μm) / PET film and ZEONOR film are heated to 150 to 180 ° C. and bonded to each other by a roll laminator. Thereafter, the PET film is peeled off. The adhesion between the PET film and the ZEONOR film is low, and the PET film can be easily peeled off. By this operation, ZEONEX 480R is transferred so as to be transferred to a film made of ZEONEX. Next, ZEONEX E48R (1-5 μm) / PET film and ZEONEX 480R (10 μm) / ZEONOR film are bonded together by a similarly heated roll laminator. Thereafter, the PET film is peeled off. By this operation, ZEONEX E48R is transferred so as to be transferred to ZEONEX 480R / ZEONOR film, and a multilayer structure of ZEONEX E48R / ZEONEX 480R / ZEONOR film can be realized. And by repeating this lamination process (lamination procedure), a multilayer structure of ZEONEX 480R / ZEONEX E48R / ZEONEX 480R /.../ ZEONOR film can be realized.

  Then, an end surface serving as a light introducing portion for entering light is formed by cutting and polishing the end portion of the film with a dicing saw. This cutting / polishing may be performed in a direction perpendicular to the direction in which the above-described cladding layer and core layer extend, or an angle of 45 degrees is given to the direction in which these layers extend. It may be made in the direction.

  Of the multilayer waveguide fabricated in the process of this example, the light from the 410 nm semiconductor laser is squeezed by the lens from the end face of the layer serving as the light introducing portion, and the light enters from the end face of the selected core layer, Light propagates throughout the core layer. Further, light from the same laser as the object light is put into the selected same layer from the direction perpendicular to the selected same layer using the light of 660 nm as the reference light. This object light has two-dimensional light information written through a spatial light modulator, and is squeezed by a lens and put perpendicular to the surface.

  This 660 nm light propagates in the multi-layer waveguide in a single mode, and causes interference at the intersection of the light of the selected layers. At this intersection, a hologram formed by points can be written and recorded. Two-dimensional large-capacity information written by a spatial light modulator is recorded at the point where the hologram is written. In addition, the hologram formed at this point can be recorded in the same manner at different locations on this layer. That is, many hologram points can be written in one layer. Furthermore, hologram points can be written in other layers as well as this one layer. In this way, a hologram can be recorded on multiple points in one layer, and further, it can be recorded in a larger capacity by making it into multiple layers.

  Further, in the case of reading, 660 nm light having the same wavelength as that at the time of writing is squeezed into an arbitrarily selected layer. Then, the light (two-dimensional information) diffracted in the direction perpendicular to the layer by the hologram in the layer into which light of 660 nm is put can be read out by the CCD camera. However, in the case of such reading, since a hologram formed by a large number of points is written in one layer, a two-dimensional optical shutter for selecting the points of each hologram is used. With this two-dimensional optical shutter, a hologram formed at a desired point can be selected. Here, as the two-dimensional optical shutter, for example, a liquid crystal spatial modulator or the like is used. In this way, a hologram memory can be realized.

  In the multilayer waveguide, the light from the 410 nm semiconductor laser is squeezed by the lens from the end face of the layer serving as the light introducing portion, and the light is introduced from the end face of the selected core layer. Is propagated. Furthermore, light of 660 nm can be put perpendicular to the waveguide layer, and the refractive index of the portion where the light of 410 nm and the light of 660 nm intersect can be changed by two-photon absorption. In this way, it is possible to record in a multilayer waveguide using pits using two-photon absorption.

[Example 2]
Next, a second embodiment different from the above-described first embodiment will be described. FIG. 6 shows the steps of Example 2 (example of forming a multilayer portion by ZEONEX 480R / silicone resin / ZEONEX 480R /...) According to the present invention. Reference numeral 61 is a PET film, reference numeral 62 is a ZEONOR film, reference numeral 63 is an uncured two-component silicone resin adhesive layer, reference numeral 64 is ZEONEX 480R, and reference numeral 65 is a roll laminator. Reference numeral 66 denotes a film spacer, which is used to adjust the pressure of the roll laminator 65. A ZEONEX 480R film (10 to 20 μm) doped with the same two-color absorbing dye (pentathiophene) and energy acceptor (DZDS) as in Example 1 was formed on a PET film by spin coating or the like, and mesitylene as a solvent was added. It is blown at 90 ° C., and a silicone resin (GE Toshiba Silicone two-part silicone resin XE5844 and XE14-C1253 is mixed at a weight ratio of 0.21: 0.79, and the refractive index is set to 1.530. The above-mentioned single mode condition [Equation 6] is satisfied by spin coating, and this is held in a state where it is not thermally cured.

  Usually, when a film composed of two layers containing a solvent is applied with a spinner, intermixing occurs. However, since this two-part silicone resin does not contain a solvent, it does not penetrate into the underlying ZEONEX layer, so that there is an advantage that problems due to intermixing do not occur. A film (10 to 20 μm) of ZEONEX 480R doped with two-color absorbing dye (pentathiophene) and energy acceptor (DZDS) was formed on this ZEONOR film by a spin coat method or the like. And these films were bonded together by roll lamination at room temperature. The lamination pressure was adjusted by inserting a film spacer 56. If the pressure is insufficient or if the silicone resin is not sufficiently dehydrated, bubbles will enter, but the bubbles will be removed by dehumidifying the silicone resin in vacuum using a thick (200 μm thick) PET film as a spacer. be able to. Then, the PET film is peeled off from the integrally bonded films. Since the adhesion between this PET film and ZEONEX is low, it can be easily peeled off.

  Then, by repeating these laminating steps (lamination procedure), a multi-layer portion having the cladding / core / cladding /... Of ZEONEX 480R / silicone resin / ZEONEX 480R is formed. Next, pressure is applied to the multilayer portion at once, and the silicone resin is thermally cured at 150 ° C. for 2 hours. In this way, the integration of ZEONEX 480R / silicone resin / ZEONEX 480R.

  Then, an end surface serving as a light introducing portion for entering light is formed by cutting and polishing the end portion of the film with a dicing saw. This cutting / polishing may be performed in a direction perpendicular to the direction in which the above-described cladding layer and core layer extend, or an angle of 45 degrees is given to the direction in which these layers extend. It may be made in the direction.

  Of the multilayer waveguide fabricated in the process of this example, the light from the 410 nm semiconductor laser is squeezed by the lens from the end face of the layer serving as the light introducing portion, and the light enters from the end face of the selected core layer, Light propagates throughout the core layer. Further, light from the same laser as the object light is put into the selected same layer from the direction perpendicular to the selected same layer using the light of 660 nm as the reference light. This object light has two-dimensional light information written through a spatial light modulator, and is squeezed by a lens and put perpendicular to the surface.

  This 660 nm light propagates in the multi-layer waveguide in a single mode, and causes interference at the intersection of the light of the selected layers. At this intersection, a hologram formed by points can be written and recorded. Two-dimensional large-capacity information written by a spatial light modulator is recorded at the point where the hologram is written. In addition, the hologram formed at this point can be recorded in the same manner at different locations on this layer. That is, many hologram points can be written in one layer. Furthermore, hologram points can be written in other layers as well as this one layer. In this way, a hologram can be recorded on multiple points in one layer, and further, it can be recorded in a larger capacity by making it into multiple layers.

  Further, in the case of reading, 660 nm light having the same wavelength as that at the time of writing is squeezed into an arbitrarily selected layer. Then, the light (two-dimensional information) diffracted in the direction perpendicular to the layer by the hologram in the layer into which light of 660 nm is put can be read out by the CCD camera. However, in the case of such reading, since a hologram formed by a large number of points is written in one layer, a two-dimensional optical shutter for selecting the points of each hologram is used. With this two-dimensional optical shutter, a hologram formed at a desired point can be selected. Here, as the two-dimensional optical shutter, for example, a liquid crystal spatial modulator or the like is used. In this way, a hologram memory can be realized.

Example 3
Next, a third embodiment different from the first and second embodiments will be described. FIG. 7 shows the steps of Example 3 (example in which a multilayer part is formed of fluorinated PMMA / PMMA (1 to 5 μm) / fluorinated PMMA /...) According to the present invention. Reference numeral 71 is a PET film, reference numeral 72 is a PMMA film (for example, trade name Technoloy of Sumitomo Chemical Co., Ltd.), and reference numeral 73 is a fluorinated PMMA (refractive index is PMMA) obtained by fluorinating 3.5% by weight of PMMA. The refractive index n ₀ = 1.489 at 633 nm), which constitutes the cladding layer here. Reference numeral 74 denotes PMMA (refractive index n ₁ = 1.495 at 633 nm), which forms the core layer here. Here, the cladding layer 73 includes a two-color absorption medium or a two-photon absorption medium. Reference numeral 75 denotes a roll laminator.

  First, a solution obtained by dissolving 3.5 wt% fluorinated PMMA in monochlorobenzene is applied on a PET film by spin coating and dried at 90 ° C. In this way, a film having a thickness of 10 to 20 μm is formed on the PET film. Subsequently, this film and a PMMA film (Sumitomo Chemical Co., Ltd., trade name Technoroy thickness 75 μm) are bonded together by a heated roll laminator. As for the temperature in that case, 100-150 degreeC is desirable. When the temperature is low, the films do not stick to each other, and when the temperature is high, there is a problem that the film melts. This layer serves as a cladding layer when it becomes a multilayer waveguide. After bonding these films together, the PET film is peeled off.

  Next, a solution obtained by dissolving PMMA in monochlorobenzene is applied onto the PET film by a spin coating method, and dried at 90 ° C. to form a film having a thickness of 1 to 5 μm on the PET film. When a multilayer waveguide is thus obtained, this layer becomes the core layer. This film and the fluorinated PMMA on technoloy prepared earlier are bonded together with a heated roll laminator. The temperature at the time of this heating is also preferably 100 to 150 ° C. as before. A PET film is peeled off from the film bonded in this way. By repeating such a laminating step (lamination procedure), a multilayer structure in which clad / core / clad / core... Is repeated can be realized.

  Then, an end surface serving as a light introducing portion for entering light is formed by cutting and polishing the end portion of the film with a dicing saw. This cutting / polishing may be performed in a direction perpendicular to the direction in which the above-described cladding layer and core layer extend, or an angle of 45 degrees is given to the direction in which these layers extend. It may be made in the direction.

  Of the multilayer waveguide fabricated in the process of this example, the light from the 410 nm semiconductor laser is squeezed by the lens from the end face of the layer serving as the light introducing portion, and the light enters from the end face of the selected core layer, Light propagates throughout the core layer. Further, light from the same laser as the object light is put into the selected same layer from the direction perpendicular to the selected same layer using the light of 660 nm as the reference light. This object light has two-dimensional light information written through a spatial light modulator, and is squeezed by a lens and put perpendicular to the surface.

  This 660 nm light propagates in the multi-layer waveguide in a single mode, and causes interference at the intersection of the light of the selected layers. At this intersection, a hologram formed by points can be written and recorded. Two-dimensional large-capacity information written by a spatial light modulator is recorded at the point where the hologram is written. In addition, the hologram formed at this point can be recorded in the same manner at different locations on this layer. That is, many hologram points can be written in one layer. Furthermore, hologram points can be written in other layers as well as this one layer. In this way, a hologram can be recorded on multiple points in one layer, and further, it can be recorded in a larger capacity by making it into multiple layers.

  Further, in the case of reading, 660 nm light having the same wavelength as that at the time of writing is squeezed into an arbitrarily selected layer. Then, the light (two-dimensional information) diffracted in the direction perpendicular to the layer by the hologram in the layer into which light of 660 nm is put can be read out by the CCD camera. However, in the case of such reading, since a hologram formed by a large number of points is written in one layer, a two-dimensional optical shutter for selecting the points of each hologram is used. With this two-dimensional optical shutter, a hologram formed at a desired point can be selected. Here, as the two-dimensional optical shutter, for example, a liquid crystal spatial modulator or the like is used. In this way, a hologram memory can be realized.

Example 4
Next, a fourth embodiment different from the first to third embodiments will be described. FIG. 8 shows a process of the fourth embodiment (example of patterned multilayer waveguide) according to the present invention. Reference numeral 81 is a PET film, reference numeral 82 is a ZEONOR film, reference numeral 83a is a ZEONEX 480R having a thickness of 10 to 20 μm (refractive index n ₀ = 1.525 at 589 nm), reference numeral 83B is a ZEONEX 480R having a thickness of 1 to 5 μm, and reference numeral 84 is a photo. Mask, reference numeral 85 is ultraviolet light, reference numeral 86 is a portion where the refractive index of ZEONEX 480R is reduced by about 10 ⁻³ to 10 ⁻² due to ultraviolet irradiation, reference numeral 87 is a linear waveguide, and reference numeral 88 is a multilayer linear waveguide. . The multilayer waveguide of this example has a configuration similar to that of the multilayer waveguide described in Example 1, but the photosensitive layer is not contained in the cladding layer. In addition, in the multilayer waveguide of this example, a step of patterning the core layer is added.

  As shown on the left side in FIG. 8, ZEONEX 480R (mesitylene solution) is applied on a PET film, dried at 90 ° C., and set to a film thickness of 1 to 5 μm. A photomask is placed on it and irradiated with ultraviolet rays. Here, the refractive index of ZEONEX 480R was reduced by about 0.01 by ultraviolet rays using a mask having a stripe pattern. Here, a combination of ZEONEX 480R, a photomask, and ultraviolet rays was used. However, any other material, laser irradiation, ion implantation, or any method can be used as long as the refractive index is changed. It does not depart from the spirit of the present invention.

Thereafter, the ZEONEX 480R / ZEONOR film produced in the process of Example 1 was irradiated with ultraviolet rays 85 to expose the ZEONEX 480R (reference numeral 83a) to the front, and the refractive index was reduced by about 0.01, that is, the refractive index was 10 ^{−. 3} and 10 ^-2 extent reduced since ZEONEX 480R (code 86). This film is heated and laminated on the film irradiated with patterning ultraviolet rays. In this way, a structure in which a straight portion having a high refractive index is sandwiched between layers having a low refractive index from the top, bottom, left, and right is a linear waveguide that can realize cladding / core / cladding. . In this way, a straight waveguide of 88 can be realized, and by repeating this operation, a multilayer linear waveguide of 89 can be realized.

  The multilayer waveguide and the manufacturing method thereof according to the present invention are not limited to the above-described embodiments, and can be appropriately selected and configured without departing from the spirit of the present invention. For example, in the multilayer waveguide described above, a two-part silicone resin was selected as a thermosetting transparent adhesive, but the thermosetting property was not limited to this example. A transparent resin adhesive capable of propagating appropriate light can be selected.

1 is a cross-sectional view of a multilayer waveguide according to the present invention. It is an expanded sectional view of the multilayer waveguide of FIG. It is a figure which shows the example of the basic production process which concerns on this invention. It is a figure which shows an example different from the basic preparation process of FIG. It is a figure which shows the process of Example 1 which concerns on this invention. It is a figure which shows the process of Example 2 which concerns on this invention. It is a figure which shows the process of Example 3 which concerns on this invention. It is a figure which shows the process of Example 4 which concerns on this invention. It is a figure which shows the structure of the conventional multilayer optical hologram memory. It is the figure which showed the reading method from the multilayer optical hologram memory of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multilayer waveguide 1A Multilayer part 10,43,53,63,73 Clad layer 20,44,54,64,74 Core layer

Claims (11)

A polymer cladding layer (set to thickness d ₀ and refractive index n ₀ ) and a polymer core layer (thickness d ₁ and refractive index n ₁ (where n ₁ > n ₀ ) are set alternately) It has a multilayer structure that is stacked so as to overlap, the loss of guided light is set to 10 dB / cm or less, and it is orthogonal to the direction in which the layer in which the light introducing portion is stacked for introducing light extends. A multilayer waveguide, characterized in that it is formed with an end face extending along a direction or a direction of 45 degrees, and the clad layer contains a photosensitive medium. The multilayer waveguide according to claim 1, wherein
When the refractive index difference Δn between the cladding layer and the core layer is set to Δn = n ₁ −n ₀ and light of wavelength λ ₁ is propagated,

D ₀ , d ₁ , Δn are set so as to satisfy The multilayer waveguide according to claim 1 or 2, wherein
A multilayer waveguide, wherein the photosensitive medium is pentathiophene. In the multilayer waveguide according to any one of claims 1 to 3,
A multilayer waveguide having a hologram memory function. On the first film, either a clad or core film is applied by spin coating, blade method, or screen printing, and the solvent is removed to form a first lamination film.
The first film was bonded to a newly prepared second film by any one of a heat laminating method, a hot press pressure bonding method, or a heat roll pressure bonding method so as to sandwich the first lamination film. Later, the first film is peeled off from the second film, and the first film for lamination is transferred from the first film to the second film so that the second film is clad. Or form a core layer,
Next, either the clad or the core film different from the first lamination film is coated on the first film by any one of a spin coating method, a blade method, and screen printing. Forming a second lamination film by removing the solvent;
In order to adhere the second lamination film to the clad layer or core layer formed on the second film, the first film is bonded to the second film by a heat laminating method, a hot press bonding method, Alternatively, after bonding by any one of the hot roll pressing methods, the first film is peeled off from the second film, and the second laminating film is transferred from the first film to the second film. In a different manner, the clad layer or core layer formed on the second film is laminated so that a new clad layer or core layer different from this is superimposed,
By repeating such a lamination procedure, a multilayer part laminated so that the clad layer and the core layer are alternately superimposed on the second film is formed,
A method for producing a multilayer waveguide, wherein an end face serving as a light introducing portion is formed by cutting in a direction orthogonal to a direction in which the stacked layers extend or a direction of 45 degrees among the multilayer portions. . On the first film, either a clad or core film is applied by spin coating, blade method, or screen printing, and the solvent is removed to form a first lamination film.
On the second film, either the clad or the core, which is different from the first lamination film, is applied by spin coating, blade or screen printing, and the solvent is removed. To form a second lamination film,
While laminating the first film and the second film, the first film and the second film are laminated while interposing a transparent adhesive having thermosetting therebetween. The first film is peeled off from the second film by laminating by either the press pressure bonding method or the roll pressure bonding method, and the first film is laminated from the first film to the second film. So as to form a clad layer and a core layer on the second film,
Next, a clad different from the clad layer or the core layer formed on the uppermost surface of the second film on the first film by any one of a spin coating method, a blade method, and screen printing. Alternatively, a film for any of the cores is applied and a solvent is removed to form a new film for lamination.
This new film for lamination is opposed to the clad layer or the core layer formed on the uppermost surface of the second film, and a thermosetting transparent adhesive is interposed therebetween. On the other hand, the first film and the second film are bonded together by a laminating method, a press-bonding method, or a roll-bonding method, and the first film is peeled off from the second film, and the first lamination is performed. The film is transferred from the first film to the second film, and a new cladding layer or core layer is laminated on the cladding layer or core layer that has been formed,
By repeating such a lamination procedure, a multilayer portion formed by laminating the clad layer and the core layer alternately on the second film is formed,
The laminated multi-layered part or single-layered part is subjected to thermocompression bonding at once or for every lamination,
A method for producing a multilayer waveguide, wherein an end face serving as a light introducing portion is formed by cutting in a direction orthogonal to a direction in which the stacked layers extend or a direction of 45 degrees among the multilayer portions. . In the manufacturing method of the multilayer waveguide according to claim 6,
A method for producing a multilayer waveguide, wherein the adhesive is a two-component thermosetting silicone resin. In the method for producing a multilayer waveguide according to any one of claims 5 to 7,
The clad film is formed of fluorinated polymethyl methacrylate (fluorination rate is set to 1 to 5% by weight, refractive index is set to n ₁ > n ₀ );
The core layer is formed of polymethylmethacrylate;
A method for producing a multilayer waveguide, characterized in that a temperature at the time of thermocompression bonding is set to 100 to 150 ° C. In the method for producing a multilayer waveguide according to any one of claims 5 to 7,
The clad film and the core film are formed of cycloolefin polymer (refractive index is set to n ₁ > n ₀ ),
A method for producing a multilayer waveguide, characterized in that a temperature at the time of thermocompression bonding is set to 150 to 180 ° C. In the manufacturing method of the multilayer waveguide according to any one of claims 5 to 9,
The method for producing a multilayer waveguide, wherein the first film is a polyethylene terephthalate film. In the manufacturing method of the multilayer waveguide according to any one of claims 5 to 9,
After forming the core film on the first film, a mask is placed on the first film, and the refractive index of the irradiated portion is changed by ultraviolet irradiation, laser irradiation, or ion implantation. Manufacturing method.

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