Method for manufacturing nonlinear optical laminate

Abstract

To provide a method for manufacturing a nonlinear optical laminate, capable of manufacturing a nonlinear optical laminate with a high yield.SOLUTION: A method for manufacturing a nonlinear optical laminate with an electro-optic polymer layer located on an objective substrate includes a first step of preparing a first laminate in which a support substrate, a light absorption layer, a first electrode, an electro-optic polymer layer, and a second electrode are laminate in this order, a second step of executing polling processing to the electro-optic polymer layer of the first laminate, a third step of acquiring a second laminate by removing the second electrode from the first laminate, a fourth step of acquiring a third laminate by laminating the objective substrate on a surface in touch with the second electrode in the second laminate, a fifth step of acquiring a fourth laminate by removing the support substrate by performing laser exfoliation of the support substrate from the third laminate, and a sixth step of acquiring a nonlinear optical laminate by removing the light absorption layer and the first electrode from the fourth laminate in this order.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method for producing a nonlinear optical laminate. [Background technology]

[0002] Electro-optic polymers are nonlinear optical materials (electro-optic materials) that have a large electro-optic coefficient compared to inorganic nonlinear optical materials such as lithium niobate and zinc telluride, and organic nonlinear optical materials such as DAST (4-N,N-dimethylamino-4'-N'-methyl-stilbazolium tosylate). Electro-optic polymers have a figure of merit (n 3 Since the refractive index (r; n: refractive index of the nonlinear optical material (electro-optic material), r: electro-optic coefficient) (Non-Patent Document 3) can be larger than that of other materials, highly efficient optical phase modulation and optical modulation can be realized by the electro-optic effect. Furthermore, while crystalline nonlinear optical materials have a large absorption coefficient due to crystal lattice vibration in the terahertz wave (electromagnetic wave with a frequency of 0.1 to 20 THz) band, electro-optic polymers have a small absorption coefficient over a wide band including the terahertz wave band. Therefore, electro-optic polymers can be used to generate and detect terahertz waves over a wide band. Furthermore, electro-optic polymers have a small difference in refractive index from the optical region to the terahertz wave band, millimeter wave band, and microwave band. Therefore, nonlinear optical elements (including electro-optic elements) containing electro-optic polymers can efficiently interact with two or more types of electromagnetic waves included in a wide range of frequencies, including the optical region, the terahertz wave band, millimeter wave band, and microwave band. Furthermore, nonlinear optical elements (including electro-optic elements) containing electro-optic polymers can perform efficient frequency conversion, phase modulation of electromagnetic waves, and the like. From this perspective, electro-optic polymers are attracting attention as materials that will be used in next-generation optical communications, wireless communications, electromagnetic wave sensing, and the like.

[0003] Electro-optic polymers include (1) guest-host electro-optic polymers, which are a mixture of a matrix polymer and electro-optic molecules, which exhibit second-order nonlinear optical effects; (2) side-chain electro-optic polymers, in which electro-optic molecules are covalently bonded to the side chains of a base polymer; (3) main-chain electro-optic polymers, in which electro-optic molecules are covalently bonded to the main chain of a base polymer; (4) cross-linked electro-optic polymers, in which cross-links are formed between matrix polymers or base polymers, or between matrix polymers or base polymers and electro-optic molecules; and (5) molecular glass electro-optic polymers. Electro-optic polymers are known as high-performance second-order nonlinear optical materials. Furthermore, electro-optic polymers exhibit second-order nonlinear optical effects.

[0004] Second-order nonlinear optical effects include second-order harmonic generation, optical rectification, sum frequency generation, difference frequency generation, optical parametric oscillation / amplification, and the electro-optic effect (Pockels effect). These second-order nonlinear optical effects enable frequency (wavelength) conversion of electromagnetic waves of various frequencies and phase control of electromagnetic waves using electric fields in nonlinear optical elements containing electro-optic polymers. Specifically, terahertz waves can be generated by frequency conversion of laser light containing two or more frequencies using the second-order nonlinear optical effect. Frequency conversion of laser light containing one or more frequencies and terahertz waves using the second-order nonlinear optical effect changes the frequency of the laser light, and terahertz waves can be detected by detecting the frequency-shifted laser light. Terahertz waves and electric fields can also be detected by using refractive index changes due to the electro-optic effect. Phase modulation of electromagnetic waves can also be achieved by using refractive index changes due to the electro-optic effect.

[0005] For an electro-optic polymer to exhibit a second-order nonlinear optical effect, the electro-optic molecules contained in the electro-optic polymer must be aligned (oriented) in the same direction as much as possible. This process is called poling. One method for poling involves fabricating a structure with poling electrodes arranged above and below the electro-optic polymer layer, heating the layer to near the glass transition temperature of the electro-optic polymer contained in the electro-optic polymer, and applying a voltage between the electrodes. The electric field applied to the electro-optic polymer layer during poling is typically 100 V / μm to 200 V / μm. Another method for poling is to perform corona discharge on an electro-optic polymer layer stacked on a lower electrode. During poling, heating the electro-optic polymer to near its glass transition temperature softens the electro-optic polymer, making the electro-optic molecules in the electro-optic polymer more easily movable by the electric field, thereby facilitating their orientation. Furthermore, the higher the glass transition temperature of the electro-optic polymer, the better the heat resistance of the manufactured nonlinear optical element and the less likely the orientation relaxation of the electro-optic molecules due to heat will occur, resulting in improved long-term thermal stability. The glass transition temperature of the electro-optic polymer is typically 50°C to 200°C. The electro-optic polymer layer can be easily formed by a method such as spin coating. The electro-optic polymer layer can be processed into a waveguide using microfabrication processes such as photolithography and dry etching.

[0006] Conventional methods for manufacturing nonlinear optical devices containing electro-optic polymers involve, for example, forming a conductive cladding layer such as a sol-gel glass on a lower electrode, forming an electro-optic polymer layer (or an electro-optic polymer waveguide structure) on top of that, and then forming an upper electrode on top of that. Poling of the electro-optic polymer layer is achieved by applying a voltage between the lower and upper electrodes (see Non-Patent Document 1). To efficiently pole an electro-optic polymer layer, a conductive cladding layer with greater conductivity than the electro-optic polymer layer must be present between the lower electrode and the electro-optic polymer layer in order to suppress voltage drop across the cladding layer. However, nonlinear optical devices fabricated using this method have a conductive cladding material that exhibits significant absorption loss of terahertz waves, making it difficult to fabricate highly efficient nonlinear optical devices that utilize terahertz waves. Furthermore, there are limitations on the placement of the electrodes, such as the need to position the lower electrode at a distance and location that allows for appropriate poling. In other words, it has been difficult to manufacture nonlinear optical elements having a cladding layer made of any material, such as a material with low absorption loss for terahertz waves (e.g., cycloolefin polymer) or an insulating material, nonlinear optical elements without a bottom electrode, or nonlinear optical elements in which a bottom electrode or the like is arranged at any distance and position. Therefore, a method has been proposed for manufacturing nonlinear optical laminates and nonlinear optical elements using such laminates by transferring a pre-poled electro-optic polymer onto a target substrate of your choice (Non-Patent Documents 2 and 4). Using this method, it is possible to manufacture nonlinear optical elements having a cladding layer made of any material, such as a material with low absorption loss for terahertz waves or an insulating material, nonlinear optical elements without a bottom electrode, or nonlinear optical elements including an electro-optic polymer in which a bottom electrode or the like is arranged at any distance and position.

[0007] A nonlinear optical element containing an electro-optic polymer can be manufactured by using a "nonlinear optical laminate." The term "nonlinear optical laminate" refers to a laminate used in manufacturing a nonlinear optical element. In a conventional method for manufacturing a nonlinear optical laminate, a poled electro-optic polymer layer is pulled and peeled from the interface on the support substrate side having a poling electrode, and transferred onto a target substrate (Patent Document 1, Non-Patent Document 2). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. WO2019 / 039530 [Non-patent literature]

[0009] [Non-Patent Document 1] Y Enami, et al., “Hybrid polymer / sol-gel waveguide modulators with exceptionally large electro-optic coefficients”, Nat. Photonics 1, 180-185 (2007). [Non-patent document 2] Takahiro Kaji, et al., “Terahertz-wave generation devices using electro-optic polymer slab waveguides and cyclo-olefin polymer clads”, Optics Express Vol. 26, Issue 23, pp. 30466-30475 (2018). [Non-patent document 3] “Organic Electro-Optics and Photonics” (LR Dalton, et al., Cambridge University Press (2015)). [Non-patent document 4] Takahiro Kaji, et al., “D-band optical modulators using electro-optic polymer waveguides and non-coplanar patch antennas”, Optics Express Vol. 31, Issue 11, pp. 17112-17121 (2023). Summary of the Invention [Problem to be solved by the invention]

[0010] In conventional methods for producing a nonlinear optical laminate, when a small substrate or a large-area wafer substrate is used as the target substrate, it is sometimes difficult to uniformly peel the electro-optic polymer layer from the support substrate having poling electrodes, because the electro-optic polymer layer is mechanically pulled and peeled from the support substrate having poling electrodes during transfer of the electro-optic polymer layer. If the electro-optic polymer layer cannot be uniformly peeled from the support substrate having poling electrodes, defective structures such as cracks are likely to occur in the electro-optic polymer layer of the nonlinear optical laminate, and therefore it is sometimes difficult to produce nonlinear optical laminates with a good yield.

[0011] The present invention has been made in view of the above circumstances, and has as its object to provide a method for producing a nonlinear optical laminate that can produce nonlinear optical laminates with a high yield. [Means for solving the problem]

[0012] A method for producing a nonlinear optical laminate according to one embodiment of the present disclosure includes the steps of: 1. A method for producing a nonlinear optical laminate comprising a target substrate and an electro-optic polymer layer disposed on the target substrate, the method comprising: a first step of preparing a first laminate in which a support substrate, a light absorbing layer, a first electrode, an electro-optical polymer layer, and a second electrode are laminated in this order; a second step of performing a poling treatment on the electro-optic polymer layer of the first laminate; a third step of removing the second electrode from the first laminate to obtain a second laminate; a fourth step of laminating the target substrate on the surface of the second laminate that was in contact with the second electrode to obtain a third laminate; a fifth step of removing the support substrate from the third laminate by laser peeling, thereby obtaining a fourth laminate; and a sixth step of removing the light absorbing layer and the first electrode from the fourth stack to obtain a nonlinear optical stack. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a method for producing a nonlinear optical laminate, which is capable of producing a nonlinear optical laminate with a high yield. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view of a first laminate for explaining the first step according to this embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the first laminate for explaining the second step according to this embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the second laminate for explaining the third step according to this embodiment. [Figure 4] FIG. 4 is a cross-sectional view of the third laminate for explaining the fourth step according to this embodiment. [Figure 5] FIG. 5 is a cross-sectional view of the fourth laminate for explaining the fifth step according to this embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a nonlinear optical laminate for explaining the sixth step according to this embodiment. [Figure 7] FIG. 7 is a view showing a bright-field microscope image of the nonlinear optical laminate according to Sample 1. As shown in FIG. [Figure 8] FIG. 8 is a diagram showing a dark-field microscope image of the nonlinear optical laminate according to Sample 1. As shown in FIG. [Figure 9]FIG. 9 is a view showing a bright-field microscope image of the nonlinear optical laminate according to Sample 101. As shown in FIG. [Figure 10] FIG. 10 is a diagram showing the absorption spectrum of the nonlinear optical laminate according to the sample 102. As shown in FIG. [Figure 11] FIG. 11 is a diagram showing the absorption spectrum of the nonlinear optical laminate according to Sample 2. As shown in FIG. [Figure 12] FIG. 12 is a diagram showing a cross-sectional scanning electron microscope image of the optical waveguide device according to Sample 4. As shown in FIG. [Figure 13] FIG. 13 is a cross-sectional view of another example of the first stack according to the present embodiment. [Figure 14] FIG. 14 is a cross-sectional view of another example of the first stack according to the present embodiment. [Figure 15] FIG. 15 is a cross-sectional view of another example of the third stack, another example of the fourth stack, and another example of the nonlinear optical stack for explaining the sealing film layer according to this embodiment. [Figure 16] FIG. 16 is a cross-sectional view of another nonlinear optical laminate for explaining the sixth step according to this embodiment. [Figure 17] FIG. 17 is a cross-sectional view of still another nonlinear optical laminate for illustrating the sixth step according to this embodiment. [Figure 18] FIG. 18 is a cross-sectional view of another nonlinear optical laminate for illustrating the sixth step according to this embodiment. [Figure 19] FIG. 19 is a cross-sectional view of yet another nonlinear optical laminate for illustrating the sixth step according to this embodiment. [Figure 20] FIG. 20 is a cross-sectional view of another nonlinear optical laminate for illustrating the sixth step according to this embodiment. [Figure 21] FIG. 21 is a cross-sectional view of still another nonlinear optical laminate for illustrating the sixth step according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described. [1] The method for producing a nonlinear optical laminate according to the present disclosure includes: A method for manufacturing a nonlinear optical laminate, comprising: a target substrate; and an electro-optic polymer layer located on the target substrate, the method comprising: a first step of preparing a first laminate in which a support substrate, a light absorbing layer, a first electrode, an electro-optical polymer layer, and a second electrode are laminated in this order; a second step of performing a poling treatment on the electro-optic polymer layer of the first laminate; a third step of removing the second electrode from the first laminate to obtain a second laminate; a fourth step of laminating the target substrate on the surface of the second laminate that was in contact with the second electrode, thereby obtaining a third laminate; a fifth step of removing the support substrate from the third laminate by laser peeling, thereby obtaining a fourth laminate; and a sixth step of removing the light absorbing layer and the first electrode from the fourth stack to obtain a nonlinear optical stack.

[0016] This makes it possible to provide a method for producing a nonlinear optical laminate, which allows the nonlinear optical laminate to be produced with a high yield.

[0017] [2] In the above [1], the light absorbing layer may be made of a first resin, thereby providing a method for producing a nonlinear optical laminate with a higher yield.

[0018] [3] In the above item [2], the glass transition temperature of the first resin may be higher than the glass transition temperature of the electro-optic polymer layer, thereby providing a method for producing a nonlinear optical laminate with a higher yield.

[0019] [4] In the above [2] or [3], the heat distortion temperature of the first resin may be higher than the glass transition temperature of the electro-optic polymer layer, thereby providing a method for producing a nonlinear optical laminate with a higher yield.

[0020] [5] In any one of the above [2] to [4], the first resin may be polyimide, thereby providing a method for producing a nonlinear optical laminate with a higher yield.

[0021] [6] In any of the above [1] to [5], the first laminate may further include a first charge blocking layer between the first electrode and the electro-optic polymer layer, thereby providing a method for producing a nonlinear optical laminate with a higher yield.

[0022] [7] In the above [6], the first charge blocking layer may be further removed from the fourth stack in the sixth step, thereby providing a method for producing a nonlinear optical laminate with a higher yield.

[0023] [8] In any of the above [1] to [7], the first laminate may further include a second charge blocking layer between the electro-optic polymer layer and the second electrode, thereby providing a method for producing a nonlinear optical laminate with a higher yield.

[0024] [9] In the above [8], the second charge blocking layer may be further removed from the first laminate in the third step, thereby providing a method for producing a nonlinear optical laminate with a higher yield.

[0025]

[10] In any of the above [1] to [9], in the fourth step, a sealing film layer may be further laminated between the second laminate and the target substrate, and the nonlinear optical laminate may further include the sealing film layer located between the target substrate and the electro-optic polymer layer. This makes it possible to provide a method for manufacturing a nonlinear optical laminate that can produce nonlinear optical laminates with a higher yield.

[0026] [Details of the embodiments of the present disclosure] An embodiment of the present disclosure (hereinafter also referred to as "the present embodiment") will be described. However, the present embodiment is not limited thereto. In this specification, the notation in the format "A to Z" means the upper and lower limits of a range (i.e., A or more and Z or less). When no unit is specified for A and a unit is specified only for Z, the unit of A and the unit of Z are the same.

[0027] [Embodiment 1: Method for producing a nonlinear optical laminate] A method for manufacturing a nonlinear optical laminate according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 6 and 13 to 21. FIG. 1 is a cross-sectional view of a first laminate for illustrating a first step according to this embodiment. FIG. 2 is a cross-sectional view of a first laminate for illustrating a second step according to this embodiment. FIG. 3 is a cross-sectional view of a second laminate for illustrating a third step according to this embodiment. FIG. 4 is a cross-sectional view of a third laminate for illustrating a fourth step according to this embodiment. FIG. 5 is a cross-sectional view of a fourth laminate for illustrating a fifth step according to this embodiment. FIG. 6 is a cross-sectional view of a nonlinear optical laminate for illustrating a sixth step according to this embodiment. FIG. 13 is a cross-sectional view of another example of the first laminate according to this embodiment. FIG. 14 is a cross-sectional view of yet another example of the first laminate according to this embodiment. FIG. 15 is a cross-sectional view of another example of the third laminate, another example of the fourth laminate, and another example of a nonlinear optical laminate for illustrating a sealing film layer according to this embodiment. FIG. 16 is a cross-sectional view of another nonlinear optical laminate for illustrating a sixth step according to this embodiment. FIG. 17 is a cross-sectional view of yet another nonlinear optical laminate for illustrating the sixth step according to this embodiment. Fig. 18 is a cross-sectional view of another nonlinear optical laminate for illustrating the sixth step according to this embodiment. Fig. 19 is a cross-sectional view of yet another nonlinear optical laminate for illustrating the sixth step according to this embodiment. Fig. 20 is a cross-sectional view of yet another nonlinear optical laminate for illustrating the sixth step according to this embodiment. Fig. 21 is a cross-sectional view of yet another nonlinear optical laminate for illustrating the sixth step according to this embodiment.

[0028] A method for producing the nonlinear optical laminate 20 according to one embodiment of the present disclosure (hereinafter also referred to as "the present embodiment") includes the following steps: A method for manufacturing a nonlinear optical laminate (20) comprising a target substrate (6) and an electro-optic polymer layer (4) located on the target substrate (6), comprising: a first step of preparing a first laminate 11 in which a support substrate 1, a light absorbing layer 2, a first electrode 3, an electro-optical polymer layer 4, and a second electrode 5 are laminated in this order; a second step of performing a poling treatment on the electro-optic polymer layer 4 of the first laminate 11; a third step of removing the second electrode 5 from the first laminate 11 to obtain a second laminate 12; a fourth step of laminating the target substrate 6 on the surface of the second laminate 12 that was in contact with the second electrode 5, thereby obtaining a third laminate 13; a fifth step of removing the support substrate 1 from the third laminate 13 by laser peeling, thereby obtaining a fourth laminate 14; and a sixth step of removing the light absorbing layer 2 and the first electrode 3 from the fourth laminate 14 to obtain a nonlinear optical laminate 20.

[0029] The present disclosure makes it possible to provide a method for manufacturing the nonlinear optical laminate 20, which is capable of manufacturing the nonlinear optical laminate 20 with a high yield. The reason for this is presumed to be as follows.

[0030] The method for producing the nonlinear optical laminate 20 according to this embodiment includes a first step of preparing a first laminate 11 in which a support substrate 1, a light absorbing layer 2, a first electrode 3, and an electro-optic polymer layer 4 are stacked in this order; a fifth step of removing the support substrate 1 from the third laminate 13 by laser peeling to obtain a fourth laminate 14; and a sixth step of removing the light absorbing layer 2 and the first electrode 3 from the fourth laminate 14 to obtain a nonlinear optical laminate 20. This makes it easier to peel the fourth laminate 14 including the electro-optic polymer layer 4 uniformly from the support substrate 1 side, and also prevents the generation of structural defects such as cracks in the electro-optic polymer layer 4 by destroying the light absorbing layer 2 that is not in direct contact with the electro-optic polymer layer 4 by laser irradiation. Therefore, the method for producing the nonlinear optical laminate 20 can prevent the generation of structural defects such as cracks in the electro-optic polymer layer 4 and improve yield.

[0031] As described above, this embodiment can provide a method for manufacturing the nonlinear optical laminate 20, which can manufacture the nonlinear optical laminate 20 with a high yield.

[0032] In this embodiment, the term "nonlinear optical laminate 20" refers to a laminate used in the manufacture of nonlinear optical elements, etc., and includes a target substrate 6 and an electro-optical polymer layer 4 located on the target substrate 6.

[0033] ≪1st process≫ The first step is to prepare a first laminate 11 in which a support substrate 1, a light absorbing layer 2, a first electrode 3, an electro-optical polymer layer 4, and a second electrode 5 are laminated in this order (FIG. 1).

[0034] The lamination may be performed by bonding the surface of the support substrate 1 and the surface of the light absorbing layer 2 together via a covalent bond, electrostatic interaction, van der Waals interaction, or the like; by bonding the surface of the light absorbing layer 2 and the surface of the first electrode 3 together via a covalent bond, electrostatic interaction, van der Waals interaction, or the like; by bonding the surface of the first electrode 3 and the surface of the electro-optical polymer layer 4 together via a covalent bond, electrostatic interaction, van der Waals interaction, or the like; or by bonding the surface of the electro-optical polymer layer 4 and the surface of the second electrode 5 together via a covalent bond, electrostatic interaction, van der Waals interaction, or the like.

[0035] <Support substrate> In this embodiment, the support substrate 1 may be made of at least one material selected from the group consisting of sapphire, quartz glass, synthetic quartz, fused silica, synthetic quartz glass, borosilicate glass, soda glass, BK7, glass, calcium fluoride, magnesium fluoride, potassium bromide, silicon, barium fluoride, and resin. The support substrate 1 may be made of a single layer or multiple layers made of different materials.

[0036] The thickness of the support substrate 1 is not particularly limited, but may be, for example, 1 μm to 100,000 μm, 10 μm to 10,000 μm, or 100 μm to 3,000 μm. The thickness of the "support substrate 1" can be determined by calculating the average thickness at any 10 locations.

[0037] The support substrate 1 may have a light transmittance in the thickness direction of the support substrate 1 at the wavelength of the laser beam used for laser peeling of 1% or more and 99.999% or less. This allows the laser beam to efficiently pass through the support substrate 1 and efficiently irradiate the light absorption layer 2 with the laser beam, thereby enabling the nonlinear optical laminate 20 to be manufactured with a higher yield. The light transmittance may be 10% or more and 99.999% or less, 30% or more and 99.999% or less, or 50% or more and 99.999% or less.

[0038] <Light absorption layer> In this embodiment, the light-absorbing layer 2 may be made of a first resin. This allows the light-absorbing layer 2 to be easily formed by a method such as spin coating, efficiently destroyed by laser irradiation, and easily removed by a method such as dry etching, thereby enabling the nonlinear optical laminate 20 to be manufactured with higher throughput and yield. Here, the phrase "the light-absorbing layer 2 is made of the first resin" encompasses not only the case where the light-absorbing layer 2 is made of only the first resin, but also the case where the layer contains inevitable impurities, etc., to the extent that the effects of the present invention are not impaired. The light-absorbing layer 2 may be made of at least one material selected from the group consisting of semiconductors, oxides, nitrides, oxynitrides, ferroelectric compounds, metals, transparent conductive materials, and glass. The light-absorbing layer 2 may be a gallium nitride (GaN)-based compound crystal layer. The light-absorbing layer 2 may be composed of a single layer or multiple layers made of different materials.

[0039] The glass transition temperature of the first resin may be higher than the glass transition temperature of the electro-optic polymer layer 4. This suppresses thermal deformation of the light absorbing layer 2 and the associated deformation of the first electrode 3 when the first laminate 11 is heated to a temperature close to the glass transition temperature of the electro-optic polymer layer 4 in the second step, thereby suppressing short circuits during the poling treatment, thereby enabling the nonlinear optical laminate 20 to be manufactured with a higher yield. The glass transition temperature of the first resin may be 20°C to 800°C, 100°C to 600°C, 150°C to 500°C, or 200°C to 400°C. The higher the glass transition temperature of the first resin, the more suppressed thermal deformation of the light absorbing layer 2 and the associated deformation of the first electrode 3 are in the poling treatment in the second step, even when the poling treatment is performed at a high temperature, thereby suppressing short circuits during the poling treatment. This allows the nonlinear optical laminate 20 to be manufactured with a higher yield, even when an electro-optic polymer with a high glass transition temperature is used. By using an electro-optic polymer with a high glass transition temperature, the heat resistance and thermal stability of the nonlinear optical laminate 20 can be improved.

[0040] The heat distortion temperature (in other words, deflection temperature under load) of the first resin may be higher than the glass transition temperature of the electro-optic polymer layer 4. This suppresses thermal deformation of the light absorbing layer 2 and the resulting deformation of the first electrode 3 when the first laminate 11 is heated to a temperature close to the glass transition temperature of the electro-optic polymer layer 4 in the second step of poling the electro-optic polymer layer 4 of the first laminate 11, thereby suppressing short circuits during the poling treatment, thereby enabling the nonlinear optical laminate 20 to be manufactured with a higher yield. The heat distortion temperature of the first resin may be 20°C or higher and 800°C or lower, 100°C or higher and 600°C or lower, 150°C or higher and 500°C or lower, or 200°C or higher and 400°C or lower. The higher the heat distortion temperature of the first resin, the more effectively the light-absorbing layer 2 and the associated first electrode 3 are prevented from thermally deforming, even when the poling treatment in the second step is performed at a high temperature. This suppresses short circuits during the poling treatment, making it possible to manufacture the nonlinear optical laminate 20 with a higher yield, even when an electro-optical polymer with a high glass transition temperature is used. Using an electro-optical polymer with a high glass transition temperature improves the heat resistance and thermal stability of the nonlinear optical laminate 20. Here, the heat distortion temperature can be rephrased as the deflection temperature under load. The heat distortion temperature refers to the temperature measured under a load of 1.80 MPa in accordance with ISO 75.

[0041] The first resin may be at least one resin selected from the group consisting of polyimide, polycarbonate, phenolic resin, aromatic polyetherketone (including polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), and polyetheretherketoneketone (PEEKK)), epoxy resin, melamine resin, polyamideimide, polyetherimide, Teflon (registered trademark), urea resin, unsaturated polyester, polyethersulfone, wholly aromatic polyester, polybenzimidazole, polysulfone, polyarylate, polydicyclopentanyl methacrylate (poly DCPMA), poly(DCPMA-co-MMA), polyadamantyl methacrylate (poly AdMA), poly(AdMA-co-MMA), cycloolefin polymer, cycloolefin copolymer, polystyrene, polyethylene, polymethylpentene, polypropylene, polyvinyl alcohol (PVA), polyethylene terephthalate, polyester, polyolefin, polyphenylene sulfide, polyurea, silicone-based resin, and fluororesin. In particular, from the viewpoint of enabling the nonlinear optical laminate to be manufactured with a higher yield, the first resin is preferably polyimide. The first resin may be a thermoplastic resin, a curable resin including a thermosetting resin, or a crosslinkable resin. In particular, when the first resin is polyimide, the glass transition temperature and heat distortion temperature of polyimide are typically 200°C to 400°C, which are higher than the glass transition temperature of the electro-optic polymer layer 4 (typically 50°C to 200°C). Therefore, when the first laminate 11 is heated to a temperature close to the glass transition temperature of the electro-optic polymer layer 4 in the second step, thermal deformation of the light absorption layer 2 and the resulting deformation of the first electrode 3 are suppressed, and short circuits during the poling treatment are suppressed, thereby enabling the nonlinear optical laminate 20 to be manufactured with a higher yield. Furthermore, when the first resin is polyimide, since polyimide has high surface smoothness, a first electrode 3 with high surface smoothness can be formed in the first step of forming the first electrode 3, and short circuits during the poling process are suppressed, making it possible to manufacture the nonlinear optical laminate 20 with a higher yield.The structure of the polyimide is not particularly limited.

[0042] The light absorbing layer 2 has an absorption coefficient of 0.01 cm at the wavelength of the laser beam used for laser peeling. -1 More than 1,000,000,000cm -1 May be less than 1cm -1 More than 1,000,000,000cm -1 May be less than 100cm -1 More than 1,000,000,000cm -1 The larger the absorption coefficient of the light absorbing layer 2 at the wavelength of the laser beam used for laser peeling, the more efficiently the laser beam is absorbed by the light absorbing layer 2 in the laser peeling in the fifth step, the more efficiently the light absorbing layer 2 is laser-destroyed, the support substrate 1 is laser-peeled from the third laminate 13 described below, and the power of the laser beam that is transmitted through the light absorbing layer 2 and the first electrode 3 and irradiated onto the electro-optic polymer layer 4 is reduced, thereby suppressing optical damage caused by the laser beam to the electro-optic polymer contained in the electro-optic polymer layer 4, and therefore it is possible to manufacture the nonlinear optical laminate 20 in which damage to the electro-optic polymer contained in the electro-optic polymer layer 4 is suppressed with a higher yield.

[0043] The thickness of the light absorbing layer 2 may be 0.0001 μm or more and 100,000 μm or less. This allows the removal of the light absorbing layer 2 in the sixth step to be completed in a short time, and in the fifth step, the power of the laser beam transmitted through the light absorbing layer 2 and the first electrode 3 and irradiated onto the electro-optic polymer layer 4 is reduced, thereby suppressing optical damage to the electro-optic polymer contained in the electro-optic polymer layer 4 due to the laser beam. This makes it possible to manufacture the nonlinear optical laminate 20 with reduced damage to the electro-optic polymer contained in the electro-optic polymer layer 4 with higher throughput and higher yield. The thickness of the light absorbing layer 2 may be 0.01 μm or more and 100 μm or less, or 0.1 μm or more and 20 μm or less. Except for the fact that the object of measurement is the "light absorbing layer 2," the thickness can be determined using the same method as the measurement method for the "thickness of the support substrate 1." The thickness of the light absorbing layer 2 is more preferably 0.1 μm or more and 20 μm or less, from the viewpoint that it is more preferable that the thickness be an appropriate thickness that is neither too thin nor too thick in order to suppress transmission of laser light while making it easy to remove.

[0044] <1st electrode> In this embodiment, the first electrode 3 may be made of a metal such as gold (Au), silver (Ag), copper (Cu), platinum (Pt), or aluminum (Al) and / or a transparent electrode material such as indium tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), InGaZnO (IGZO), aluminum-doped zinc oxide (AZO), or gallium-doped zinc oxide (GZO). The first electrode 3 may be made of a single layer or multiple layers made of different materials.

[0045] The thickness of the first electrode 3 is not particularly limited, and may be, for example, 0.0001 μm to 100,000 μm, 0.001 μm to 100 μm, or 0.01 μm to 10 μm. Except for the fact that the object of measurement is the "first electrode 3," the thickness can be determined in the same manner as the measurement method for the "thickness of the support substrate 1."

[0046] <Electro-optic polymer layer> In this embodiment, the "electro-optic polymer layer 4" refers to a layer made of a second resin. The second resin refers to an electro-optic polymer.

[0047] In this embodiment, an "electro-optic polymer" (hereinafter sometimes referred to as an "EO polymer") is a polymer that exhibits a second-order nonlinear optical effect, and includes (1) a guest-host electro-optic polymer in which a matrix polymer and electro-optic molecules are mixed, (2) a side-chain electro-optic polymer in which electro-optic molecules are covalently bonded to the side chains of a base polymer, (3) a main-chain electro-optic polymer in which electro-optic molecules are covalently bonded to the main chain of a base polymer, (4) a cross-linked electro-optic polymer in which cross-links are formed between matrix polymers or base polymers, or between a matrix polymer or base polymer and electro-optic molecules, and (5) a molecular glass electro-optic polymer. A molecular glass electro-optic polymer is an electro-optic polymer (electro-optic material) containing electro-optic molecules as the main component, and these electro-optic molecules may be cross-linked to each other. A guest-host electro-optic polymer can also be understood as a composition containing a matrix polymer and electro-optic molecules.

[0048] Examples of second-order nonlinear optical effects include second-order harmonic generation, optical rectification, sum frequency generation, difference frequency generation, optical parametric oscillation / amplification, and electro-optic effect (Pockels effect).

[0049] In this embodiment, the term "matrix polymer" refers to a polymer that serves as the base of an electro-optical polymer. The matrix polymer includes an organic polymer that serves as a host for a guest-host electro-optical polymer. The term "base polymer" refers to a polymer that serves as the basic skeleton of an electro-optical polymer. The base polymer includes an organic polymer that serves as the main chain of a side-chain, main-chain, or cross-linked electro-optical polymer. The matrix polymer and base polymer are preferably transparent polymers that do not scatter light and are used as optical materials, such as (meth)acrylate polymers (e.g., polymethyl methacrylate (PMMA)), polyamide, polyimide, polycarbonate (e.g., poly[Bisphenol A carbonate-co-4,4'-(3,3,5-trimethylcyclohexylidene)diphenol carbonate], etc.), polydicyclopentanyl methacrylate (polyDCPMA), polyadamantyl methacrylate (polyAdMA), poly(DCPMA-co-MMA), poly(AdMA-co-MMA), cycloolefin polymers, cycloolefin copolymers, polystyrene, polyethylene, polymethylpentene, polypropylene, polyvinyl alcohol (PVA), polyethylene terephthalate, polysulfone, polyethersulfone, polyester, polyolefin, polyphenylene sulfide, polyurea, silicone resins, epoxy resins, and fluororesins. The organic polymers may be used singly or in combination.

[0050] In this embodiment, the term "electro-optical molecule" refers to a compound that exhibits a second-order nonlinear optical effect. Examples of electro-optical molecules include compounds that exhibit a second-order nonlinear optical effect described in U.S. Patent No. 6,067,186, JP 2004-501,159 A, WO 2011 / 024774 A1, "Organic Materials for Nonlinear Optics" (edited by the Chemical Society of Japan, Quarterly Chemistry Review No. 15 (1992)), "Organic Nonlinear Optical Materials" (Ch. Bosshard et al., Gordon and Breach Publishers (1995)), "Latest Technology of Optical Organic Materials for Information and Communications" (edited by Kaino Toshikuni, CMC Publishing (2007)), and "Molecular Nonlinear Optics" (ed. J. Zyss, Academic Press (1994)).

[0051] The electro-optic molecule is not particularly limited as long as it exhibits a second-order nonlinear optical effect, but is preferably a compound having a conjugated chemical structure and further having an electron-donating group and an electron-withdrawing group in the molecule. Examples of conjugated chemical structures include aromatic compounds such as benzene, naphthalene, anthracene, perylene, biphenyl, indene, and stilbene, heterocyclic compounds such as furan, pyran, pyrrole, imidazole, pyrazole, thiophene, thiazole, pyridine, pyridazine, pyrimidine, pyrazine, quinoline, and coumarin, and compounds in which these compounds are bonded to each other via a carbon-carbon unsaturated bond or a nitrogen-nitrogen unsaturated bond.

[0052] Examples of the electron-donating group include an amino group which may be substituted with an alkyl group, an aryl group, or an acyl group, an alkoxy group, an allyloxy group, and a thioether group. Examples of the electron-withdrawing group include a nitro group, a cyano group, a dicyanovinyl group, a tricyanovinyl group, a halogen atom, a carbonyl group, a sulfone group, a perfluoroalkyl group, a tricyanovinylfuran group, and a tricyanofuran group.

[0053] Examples of electro-optical molecules include compounds represented by the following structural formulas [A-1] to [A-7]. These can be used alone or in combination of two or more.

[0054] [ka]

[0055] [ka]

[0056] The content of the electro-optical molecules is not particularly limited, but is typically about 1 to 70 mass %, preferably about 5 to 60 mass %, and more preferably about 10 to 50 mass %, of the total amount of the matrix polymer or base polymer and the electro-optical molecules (corresponding to the total mass of the electro-optical polymer). The above content is the same whether the electro-optical polymer is a side chain type or a main chain type. Here, in the case of a side chain type electro-optical polymer, the content of the electro-optical molecules is determined based on the electro-optical molecules from which the side chain portions are derived. In the case of a main chain type electro-optical polymer, the content of the electro-optical dye is determined based on the electro-optical molecular portion in the main chain.

[0057] The electro-optic polymer may be, for example, a side-chain electro-optic polymer having repeating units represented by formulas (1) to (3). In the formulas, p, q, and r each represent a positive integer. Here, the side-chain electro-optic polymer may be a copolymer of a repeating unit constituting a base polymer that does not contain an electro-optic molecular moiety as a side chain (e.g., a repeating unit represented by formula (1) or (3)) and a repeating unit constituting a base polymer that contains an electro-optic molecular moiety as a side chain (e.g., a repeating unit represented by formula (2)). In this case, the copolymer may be any of a random copolymer, a block copolymer, and a graft copolymer.

[0058] [ka]

[0059] The thickness of the electro-optic polymer layer 4 is not particularly limited, and may be, for example, 0.0001 μm to 100,000 μm, 0.001 μm to 100 μm, or 0.01 μm to 20 μm. The thickness of the electro-optic polymer layer 4 can be determined by the same method as the method for measuring the "thickness of the support substrate 1," except that the object of measurement is the "electro-optic polymer layer 4."

[0060] The method for producing the electro-optic polymer layer 4 is not particularly limited, but examples thereof include spin coating, dip coating, spray coating, bar coating, flow coating, gravure coating, and roll coating.

[0061] <Second electrode> In this embodiment, the second electrode 5 may be made of a metal such as gold (Au), silver (Ag), copper (Cu), platinum (Pt), or aluminum (Al) and / or a transparent electrode material such as indium tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), InGaZnO (IGZO), aluminum-doped zinc oxide (AZO), or gallium-doped zinc oxide (GZO). The second electrode 5 may be made of a single layer or multiple layers made of different materials.

[0062] The thickness of the "second electrode 5" is not particularly limited, and may be, for example, 0.0001 μm to 100,000 μm, 0.001 μm to 100 μm, or 0.01 μm to 10 μm. Except for the fact that the object of measurement is the "second electrode 5," the thickness can be determined in the same manner as the measurement method for the "thickness of the support substrate 1."

[0063] <First charge blocking layer> In the first laminate 11, a first charge blocking layer 7a may be further laminated between the first electrode 3 and the electro-optic polymer layer 4 (FIG. 13). This suppresses the current in the poling treatment in the second step, thereby suppressing short circuits during the poling treatment, thereby enabling the nonlinear optical laminate to be manufactured with a higher yield. Note that, when the first charge blocking layer 7a is further laminated between the first electrode 3 and the electro-optic polymer layer 4 in the first laminate 11, the first charge blocking layer 7a may be further removed from the fourth laminate 14 in the sixth step described below. Methods for further removing the first charge blocking layer 7a from the fourth laminate include dry etching, wet etching, chemical mechanical polishing, and mechanical polishing.

[0064] The first charge blocking layer 7a may be made of at least one material selected from the group consisting of, for example, oxides (Al2O3, HfO2, SiO2, TiO2, SrTiO3, Ta2O5, Gd2O3, ZrO2, Ga2O3, V2O5, Co3O4, ZnO, ZnO:Al, ZnO:B, In2O3:H, WO3, MoO3, Nb2O5, NiO, MgO, RuO2), fluorides (MgF2, AlF3), nitrides (TiN, TaN, Si3N4, AlN, GaN, WN, HfN, NbN, GdN, VN, ZrN), sulfides (ZnS, MoS2), aluminum alkoxide, benzocyclobutene (BCB), polymethylsiloxane, polydimethylsiloxane, and resin. The first charge blocking layer 7a may be formed by atomic layer deposition, plasma CVD, physical vapor deposition, or spin coating. The first charge blocking layer 7a may have the function of suppressing current during the poling treatment in the second step. The first charge blocking layer 7a may be composed of a single layer or multiple layers made of different materials. The thickness of the first charge blocking layer 7a may be, for example, 0.000001 μm to 10,000 μm, 0.00001 μm to 10 μm, or 0.0001 μm to 0.1 μm. The thickness of the first charge blocking layer 7a can be determined using the same method as the measurement method for the "thickness of the support substrate 1," except that the measurement target is the "first charge blocking layer 7a."

[0065] <Second charge blocking layer> In the first laminate 11, a second charge blocking layer 7b may be further laminated between the electro-optic polymer layer 4 and the second electrode 5 (FIG. 14). This suppresses the current in the poling treatment in the second step, thereby suppressing short circuits during the poling treatment, and therefore the nonlinear optical laminate 20 can be manufactured with a higher yield. Note that when the second charge blocking layer 7b is further laminated between the electro-optic polymer layer 4 and the second electrode 5 in the first laminate 11, the second charge blocking layer 7b may be further removed from the first laminate 11 in the third step described below. Methods for further removing the second charge blocking layer 7b from the first laminate 11 include dry etching, wet etching, chemical mechanical polishing, and mechanical polishing.

[0066] The second charge blocking layer 7b may be made of at least one material selected from the group consisting of, for example, oxides (Al2O3, HfO2, SiO2, TiO2, SrTiO3, Ta2O5, Gd2O3, ZrO2, Ga2O3, V2O5, Co3O4, ZnO, ZnO:Al, ZnO:B, In2O3:H, WO3, MoO3, Nb2O5, NiO, MgO, RuO2), fluorides (MgF2, AlF3), nitrides (TiN, TaN, Si3N4, AlN, GaN, WN, HfN, NbN, GdN, VN, ZrN), sulfides (ZnS, MoS2), aluminum alkoxide, benzocyclobutene (BCB), polymethylsiloxane, polydimethylsiloxane, and resin. The second charge blocking layer 7b may be formed by atomic layer deposition, plasma CVD, physical vapor deposition, or spin coating. The second charge blocking layer 7b may have the function of suppressing current during the poling treatment in the second step. The second charge blocking layer 7b may be composed of a single layer or multiple layers made of different materials. The thickness of the second charge blocking layer 7b may be, for example, 0.000001 μm to 10,000 μm, 0.00001 μm to 10 μm, or 0.0001 μm to 0.1 μm. The thickness of the second charge blocking layer 7b can be determined using the same method as the measurement method for the "thickness of the support substrate 1," except that the measurement target is the "second charge blocking layer 7b."

[0067] ≪Second process≫ The second step is a step of carrying out a poling treatment on the electro-optic polymer layer 4 of the first laminate 11 (FIG. 2).

[0068] In this embodiment, the term "poling treatment" refers to a treatment for orienting electro-optical molecules and fixing the orientation. The poling treatment is not particularly limited, and examples thereof include a method of sandwiching the electro-optical polymer layer 4 between a first electrode 3 and a second electrode 5 and applying a voltage near the glass transition temperature of the electro-optical polymer layer 4, and a method of subjecting the electro-optical polymer layer 4 to corona discharge. For example, as shown in FIG. 2, the electro-optical polymer layer 4 may be poled by applying a voltage between the first electrode 3 and the second electrode 5 near the glass transition temperature of the electro-optical polymer layer 4. Note that in FIGS. 2 to 6, the arrows indicate that the electro-optical molecules in the electro-optical polymer layer 4 are aligned by the poling treatment.

[0069] ≪3rd process≫ The third step is a step of obtaining a second laminate 12 by removing the second electrode 5 from the first laminate 11 (in other words, the first laminate 11 that has been subjected to the poling treatment in the second step) (Figure 3).

[0070] Methods for removing the second electrode 5 from the first laminate 11 (in other words, the first laminate 11 that has been subjected to the poling treatment in the second step) include wet etching, dry etching, chemical mechanical polishing, mechanical polishing, etc.

[0071] ≪4th process≫ The fourth step is a step of obtaining a third laminate 13 by laminating a target substrate 6 on the surface of the second laminate 12 that was in contact with the second electrode 5 (FIG. 4). The "surface of the second laminate 12 that was in contact with the second electrode 5" can also be understood as the "surface of the third laminate exposed by the third step." Examples of lamination methods include a method of performing plasma treatment and silane coupling treatment followed by pressure bonding.

[0072] <Target board> In this embodiment, the "target substrate 6" refers to a substrate that supports the electro-optic polymer layer 4. The target substrate 6 may have a single layer structure or a multi-layer structure depending on the application of the nonlinear optical laminate 20 to be manufactured. The target substrate 6 can be appropriately set depending on the application of the nonlinear optical laminate 20 to be manufactured.

[0073] Examples of the target substrate 6 include glass (e.g., BK7, etc.), SiO2 (e.g., quartz glass), sol-gel glass (e.g., MAPTMS, etc.), fluororesin (e.g., PTFE, CYTOP (Asahi Glass, registered trademark), Teflon (The Chemours Company, registered trademark) AF, etc.), polycarbonate (e.g., poly[Bisphenol A carbonate-co-4,4'-(3,3,5-trimethylcyclohexylidene)diphenol carbonate], etc.), (meth)acrylate polymer (e.g., polymethyl methacrylate (PMMA)), polydicyclopentanyl methacrylate (poly DCPMA), polyadamantyl methacrylate (poly AdMA), poly(DCPMA-co-MMA), poly(AdMA-co-MMA), cycloolefin polymer (e.g., ZEONEX (Nippon Zeon, registered trademark), ZEONOR (Nippon Zeon, registered trademark), ARTON (JSR, registered trademark), etc.), cycloolefin copolymer (TOPAS (Topas Advanced Polymers)), etc.), and the like. GmbH, registered trademark), APEL (Mitsui Chemicals, registered trademark), etc.), Tsurupica (registered trademark), Daikyo Resin CZ, polystyrene, polyethylene, polymethylpentene (TPX (Mitsui Chemicals, registered trademark)), polypropylene, polyimide, polyvinyl alcohol (PVA), polyethylene terephthalate, ultraviolet curing resins (e.g., SU8, UV15 and UV15LV manufactured by Masterbond, NOA61, NOA65, NOA71, NOA73 manufactured by Norland), electro-optical polymers (including poly(Disperse Red 1 acrylate), poly(Disperse Red 1 methacrylate), poly(Disperse Red 13 acrylate), poly(Disperse Red 13 methacrylate), poly(Disperse Orange 3 acrylamide), poly(Disperse Orange 3 methacrylamide), poly(Disperse Yellow 7 acrylate), poly(Disperse Yellow 7 methacrylate)), and the like.These can be used alone or in combination of two or more. In addition, the target substrate 6 may contain dye molecules (including electro-optical molecules).

[0074] Examples of the target substrate 6 include semiconductors, oxides, nitrides, oxynitrides, ferroelectric compounds, metals, transparent conductive materials, etc. Examples of semiconductors include Group IV semiconductors such as diamond (C), silicon (Si), boron-doped silicon, phosphorus-doped silicon, silicon carbide (SiC), silicon germanium (SiGe), and germanium (Ge), Group III-V semiconductors such as gallium arsenide (GaAs), indium phosphide (InP), gallium nitride (GaN), and gallium phosphide (GaP), and Group II-VI semiconductors such as zinc selenide (ZnSe), cadmium sulfide (CdS), cadmium selenide (CdSe), cadmium telluride (CdTe), zinc sulfide (ZnS), zinc selenide (ZnSe), zinc telluride (ZnTe), and cadmium zinc telluride (CdZnTe). Examples of oxides include silicon oxide, metal oxides (e.g., titanium oxide (TiO), aluminum oxide (AlO), hafnium oxide (HfO), lanthanum oxide (LaO), zirconium dioxide (ZrO), yttrium oxide (YO), tantalum pentoxide (TaO), zinc oxide (ZnO), gallium oxide (GaO), magnesium oxide (MgO), etc.), hafnium silicate (HfSiO), and silicon dioxide (SiO). Examples of nitrides include silicon nitride, carbon nitride, and metal nitrides (e.g., aluminum nitride (AlN), titanium nitride (TiN), and hafnium nitride (HfN)). Examples of oxynitrides include silicon oxynitride and metal oxynitride (e.g., aluminum oxynitride (AlON), hafnium oxynitride (HfON), etc.). Examples of ferroelectric compounds include lithium niobate (LiNbO3), lithium tantalate (LiTaO3), and lanthanum-doped lead zirconate titanate (PLZT). Examples of metals include gold (Au), silver (Ag), copper (Cu), platinum (Pt), and aluminum (Al). Examples of transparent conductive materials include ITO, IZO, FTO (fluorine-doped tin oxide), IGZO (InGaZnO), AZO (aluminum-doped zinc oxide), GZO (gallium-doped zinc oxide), and SnO2. These can be used alone or in combination of two or more.The above materials are preferably used for the layer in contact with the electro-optic polymer layer 4 when the target substrate 6 has a multi-layer structure.

[0075] The thickness of the target substrate 6 is not particularly limited, and may be, for example, 1 μm to 100,000 μm, 10 μm to 10,000 μm, or 100 μm to 3,000 μm. The thickness of the target substrate 6 can be determined using the same method as the method for measuring the "thickness of the support substrate 1," except that the measurement object is the "target substrate 6."

[0076] <Sealing film layer> In the fourth step, a sealing film layer 8 may be further laminated between the second laminate 12 and the target substrate 6 (FIG. 15). This enables the nonlinear optical laminate 20 to be manufactured with a higher yield. The sealing film layer 8 may have a function of suppressing the permeation of oxygen and water. This suppresses photodegradation of the manufactured nonlinear optical laminate 20, thereby enabling the nonlinear optical laminate 20 with excellent light resistance to be manufactured with a higher yield. Note that, when the sealing film layer 8 is further laminated between the second laminate 12 and the target substrate 6 in the fourth step, the nonlinear optical laminate 20 further includes the sealing film layer 8 located between the target substrate 6 and the electro-optic polymer layer 4.

[0077] The sealing film layer may be made of at least one material selected from the group consisting of, for example, oxides (Al2O3, HfO2, SiO2, TiO2, SrTiO3, Ta2O5, Gd2O3, ZrO2, Ga2O3, V2O5, Co3O4, ZnO, ZnO:Al, ZnO:B, In2O3:H, WO3, MoO3, Nb2O5, NiO, MgO, RuO2), fluorides (MgF2, AlF3), nitrides (TiN, TaN, Si3N4, AlN, GaN, WN, HfN, NbN, GdN, VN, ZrN), sulfides (ZnS, MoS2), aluminum alkoxide, benzocyclobutene (BCB), polymethylsiloxane, polydimethylsiloxane, and resin. The sealing film layer 8 may be formed by atomic layer deposition, plasma CVD, physical vapor deposition, or spin coating. The sealing film layer 8 may be composed of a single layer or multiple layers made of different materials. The thickness of the sealing film layer 8 may be, for example, 0.0001 μm to 100,000 μm, 0.001 μm to 100 μm, or 0.01 μm to 10 μm. The thickness of the sealing film layer 8 can be determined using the same method as the measurement method for the "thickness of the support substrate 1," except that the measurement target is the "sealing film layer 8."

[0078] ≪5th process≫ The fifth step is a step of removing the support substrate 1 from the third laminate 13 by laser peeling, thereby obtaining a fourth laminate 14 ( FIG. 5 ). Here, “laser peeling the support substrate 1 from the third laminate 13” means that the light absorbing layer 2 is irradiated with a laser beam to destroy the light absorbing layer 2, thereby peeling the support substrate 1 from the third laminate 13. Note that “laser peeling” can also be rephrased as “peeling by laser lift-off.” Because the light absorbing layer 2 is destroyed by a laser beam, the electro-optic polymer layer 4 can be easily peeled uniformly from the support substrate 1, thereby improving the yield of the method for manufacturing the nonlinear optical laminate 20. Note that the light absorbing layer 2 may be completely destroyed by the laser peeling (in other words, the fourth laminate 14 may not include the light absorbing layer 2), or a remnant of the light absorbing layer 2 may remain (in other words, the fourth laminate 14 may include the light absorbing layer 2). In the laser peeling, the light absorbing layer 2 may be destroyed by irradiating a laser beam from the surface of the third stack 13 on the support substrate 1 side. In the laser peeling, the destruction of the light absorbing layer 2 by irradiation with a laser beam may be destruction associated with one-photon absorption, two-photon absorption, three-photon absorption, or multi-photon absorption.

[0079] The wavelength of the laser beam may be 100 nm or more and 10,000 nm or less. This allows the light absorption layer to be efficiently destroyed by laser irradiation, making it possible to manufacture the nonlinear optical laminate 20 with a higher yield. The wavelength of the laser beam may be 100 nm or more and 1,100 nm or less, 100 nm or more and 400 nm or less, or 100 nm or more and 300 nm or less.

[0080] The repetition frequency of the laser beam may be 0.001 kHz or more and 1,000,000,000 kHz or less. This allows the nonlinear optical laminate 20 to be manufactured with a higher yield. The repetition frequency of the laser beam may be 0.01 kHz or more and 1,000,000 kHz or less, or 0.1 kHz or more and 1000 kHz or less. The laser beam may be a continuous wave laser beam.

[0081] The average output power of the laser beam may be 0.0001 W or more and 100,000 W or less. This allows for a higher yield of manufacturing the nonlinear optical laminate 20. The average output power of the laser beam may be 0.001 W or more and 100 W or less, or 0.01 W or more and 10 W or less.

[0082] The pulse width of the laser beam may be 0.001 ps or more and 10,000,000 ps or less. This allows the nonlinear optical laminate 20 to be manufactured with a higher yield. The pulse width of the laser beam may be 0.1 ps or more and 1,000,000 ps or less, or 1 ps or more and 100,000 ps or less. The laser beam may be a continuous wave laser beam.

[0083] The diameter of the beam when the laser beam is irradiated onto the light absorbing layer 2 (hereinafter also referred to as "beam diameter") may be 0.1 μm or more and 1000 μm or less. This enables the nonlinear optical laminate 20 to be manufactured with a higher yield. The beam diameter may be 0.05 μm or more and 10,000 μm or less, or 0.01 μm or more and 100,000 μm or less. The smaller the beam diameter, the easier it is to efficiently destroy the light absorbing layer 2 even with a low laser beam power, but the throughput of laser removal tends to decrease.

[0084] ≪6th process≫ The sixth step is a step of removing the light absorbing layer 2 and the first electrode 3 from the fourth stack 14 to obtain a nonlinear optical stack 20 (FIGS. 6, 16 to 21). Methods for removing the light absorbing layer 2 from the fourth stack 14 include dry etching, wet etching, chemical mechanical polishing, or mechanical polishing to remove the light absorbing layer 2 from the fourth stack 14. Methods for removing the first electrode 3 from the fourth stack 14 include wet etching, dry etching, chemical mechanical polishing, or mechanical polishing to remove the first electrode 3 from the fourth stack 14.

[0085] The method for manufacturing the nonlinear optical laminate 20 according to this embodiment may further include other steps such as "a step of processing the poled electro-optic polymer layer 4 after the sixth step." Examples of such other steps include: (1) Laminating another layer (not shown) on the poled electro-optic polymer layer 4 by sputtering or the like; (2) forming a mask on the electro-optic polymer layer 4 that has been subjected to poling treatment by photolithography or the like, and processing the electro-optic polymer layer 4 into a waveguide structure or the like by dry etching or the like (not shown); (3) Laminating a new layer (e.g., an upper cladding layer) on top of the waveguide obtained by processing the poled electro-optic polymer layer 4 (not shown); (4) laminating another poled electro-optical polymer layer 4 on the poled electro-optical polymer layer 4 laminated on the support (not shown); Examples include: [Example]

[0086] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0087] [Example 1] <<Production of nonlinear optical laminates>> Nonlinear optical laminates according to Samples 1 to 4, 101, and 102 were prepared as follows.

[0088] <Preparation of Nonlinear Optical Laminates for Samples 1 to 4> First, a support substrate, a light-absorbing layer, a first electrode, an electro-optic polymer layer, and a second electrode were stacked in this order to obtain a first laminate (step 1). The support substrate was prepared by dicing a 30 mm × 35 mm, 600 μm-thick sapphire substrate (C-face (0001)) using a diamond blade. The light-absorbing layer was prepared by spin-coating a polyimide coating material (non-photosensitive polyimide (Semicofine®) manufactured by Toray Industries, Inc.) onto the surface of the support substrate and heat-treating it at 300°C on a hot plate to obtain a 2.8 μm-thick light-absorbing layer. The first electrode was prepared by RF sputtering a 100 nm-thick IZO film on the surface of the light-absorbing layer, followed by oxygen plasma treatment using a reactive ion etching apparatus, followed by treatment with an amino-containing silane coupling agent (KBP-90 manufactured by Shin-Etsu Chemical Co., Ltd.). The electro-optic polymer layer was a layer of a side-chain electro-optic polymer (random copolymer) containing repeating units of the following chemical formulas (1) to (3) (where p, q, and r are each positive integers), which was formed by spin coating and then heat-treated at 170°C. The glass transition temperature of the electro-optic polymer used in the preparation of Samples 1 to 4 was 160°C. For Samples 1 to 4, the rotation speed of the spin coating in the first step of forming the electro-optic polymer layer, the concentration of the electro-optic polymer solution used for spin coating, and the thickness of the electro-optic polymer layer in the first laminate are shown in Table 1. For the second electrode, an IZO film was prepared by RF sputtering to a thickness of 100 nm.

[0089] [ka]

[0090] Next, while heating the first laminate to a temperature of 148°C, a voltage calculated from the voltage per unit thickness of the electro-optic polymer layer listed in the "Voltage per unit thickness of the electro-optic polymer layer in the poling treatment of the second step [V / μm]" column in Table 1 and the thickness of the electro-optic polymer layer listed in the "Thickness of the electro-optic polymer layer in the first laminate [μm]" column in Table 1 was applied between the first electrode and the second electrode of the first laminate to perform a poling treatment, and the first laminate was cooled to room temperature while maintaining the voltage (second step). The electro-optic coefficient (r 33 ) is compared with the "electro-optic coefficient at a wavelength of 1308 nm after the second process (r 33 ) and "Electro-optic coefficient at wavelength 1550 nm after the second process (r 33 )" column of Sample 1. 33 )" and "Electro-optic coefficient at wavelength 1308 nm after the second process (r 33 The difference between the "electro-optic coefficient (r 33 )" and "Electro-optic coefficient at wavelength 1550 nm after the second process (r 33 The difference between "1" and "2" is due to variations in the values. Next, the second electrode was removed from the first laminate by wet etching to obtain a second laminate (third step).

[0091] Next, one surface of the target substrate (the SiO2 side for Sample 1, the synthetic quartz side for Sample 2, the ITO side for Sample 3, and the cycloolefin polymer (ZEONOR (Zeon Corporation, registered trademark)) side for Sample 4) listed in Table 1 was oxygen plasma treated using a reactive ion etching apparatus, followed by treatment with a silane coupling agent (KBP-90, manufactured by Shin-Etsu Chemical Co., Ltd.) having an amino group. The surface of the second laminate that had been in contact with the second electrode was then oxygen plasma treated using a reactive ion etching apparatus. The second laminate and the target substrate were then pressure-bonded at 100°C so that the oxygen plasma-treated and silane coupling agent-treated surface of the target substrate was in contact with the electro-optic polymer layer side of the second laminate. This laminate was then laminated to the second laminate, yielding a third laminate (step 4). Next, using a laser processing machine "Laser Saw (DFL7560L)" (trademark) manufactured by Disco Corporation, the support substrate was removed by laser peeling from the third stack, thereby obtaining a fourth stack (step 5). Here, the laser irradiation for laser peeling was performed from the side of the third stack facing the support substrate. Next, the light absorption layer was removed from the fourth stack by dry etching using a reactive ion etching device, and the first electrode was removed by wet etching, thereby obtaining a nonlinear optical stack (step 6). Note that each of target substrates A to D refers to a target substrate having the following configuration. For example, when "2 μm SiO2 / 400 μm Si substrate" is described below, it means that "2 μm SiO2" and "400 μm Si substrate" are stacked in this order. (Target boards A to D) Target substrate A: 2 μm SiO2 / 400 μm Si substrate (substrate size: 25 mm × 25 mm) Target substrate B: Synthetic quartz glass substrate (substrate size: 25 mm x 25 mm x 1 mm) Target substrate C: ITO glass substrate (substrate size: 25 mm x 25 mm x 0.7 mm, ITO layer thickness: 9 nm) Target substrate D: 23 μm cycloolefin polymer (ZEONOR (Zeon Corporation, registered trademark)) / 800 nm SiO2 / 5 nm Ti / 200 nm Au / 10 nm Ti / 2 μm SiO2 / 400 μm Si substrate (substrate size: 25 mm × 25 mm)

[0092] <Preparation of Nonlinear Optical Laminate of Sample 101> To prepare Sample 101, a solution (15% by mass) of an electro-optic polymer with a glass transition temperature of 178°C was spin-coated at 3000 rpm onto an ITO glass substrate (substrate size: 40 mm × 30 mm × 0.7 mm, ITO layer thickness: 9 nm) as a support substrate, and then heat-treated at 180°C to form an electro-optic polymer layer. A 100-nm-thick IZO film was then formed on the electro-optic polymer layer by RF sputtering, yielding a first laminate. The thickness of the electro-optic polymer layer in the first laminate was 1.3 μm. A poling treatment was performed by applying a voltage (156 V) calculated from the voltage per unit thickness of the electro-optic polymer layer (120 V / μm) and the thickness of the electro-optic polymer layer (1.3 μm) between the ITO electrode below the electro-optic polymer layer and the IZO electrode above the electro-optic polymer layer, and the layer was cooled to room temperature while maintaining the voltage. The electro-optic coefficient (r 33The IR spectra were 45.0 pm / V at a wavelength of 1308 nm and 32.4 pm / V at a wavelength of 1550 nm. Next, the upper IZO electrode was removed from the first stack by wet etching to obtain a second stack. Next, the surface of the target substrate, which was composed of a 2.3 μm UV-curable resin (NTT-AT, FE4048), a 100 nm IZO layer, a 2 μm SiO layer, and a 500 μm Si substrate layer stacked in this order, was treated with oxygen plasma on the UV-curable resin (NTT-AT, FE4048) side using a reactive ion etching system, followed by treatment with an amino-functional silane coupling agent (Shin-Etsu Chemical Co., Ltd., KBP-90). The surface of the second stack, which was the electro-optic polymer layer side, was also treated with oxygen plasma on a reactive ion etching system. Thereafter, the second' laminate and the target substrate were pressure-bonded at 100°C so that the surface of the target substrate that had been treated with oxygen plasma and a silane coupling agent was in contact with the surface of the second' laminate facing the electro-optic polymer layer, thereby laminating the target substrate onto the second' laminate to obtain a third' laminate. Next, the support substrate (ITO glass substrate) was removed from the third' laminate by mechanically pulling and peeling it, thereby obtaining a nonlinear optical laminate according to Sample 101.

[0093] <Preparation of Nonlinear Optical Laminate of Sample 102> To prepare Sample 102, an electro-optic polymer layer was formed by spin coating on a substrate similar to the target substrate (synthetic quartz glass substrate) of Sample 2 using the same electro-optic polymer as used in preparing Sample 2, followed by heat treatment at 170°C to prepare a nonlinear optical laminate intermediate. The electro-optic polymer layer of Sample 102 was formed using an electro-optic polymer solution of the same concentration as Sample 2 and at the same spin coating rotation speed as Sample 2. The electro-optic polymer layer side of the nonlinear optical laminate intermediate was then subjected to oxygen plasma treatment similar to the oxygen plasma treatment performed on the electro-optic polymer layer side of Sample 2 in the fourth step, thereby obtaining a nonlinear optical laminate according to Sample 102. The thickness of the electro-optic polymer layer in the nonlinear optical laminate according to Sample 102 was 130 nm.

[0094] In this manner, nonlinear optical laminates according to Samples 1 to 4, 101 and 102 were prepared.

[0095] [Table 1]

[0096] <<Evaluation of properties of laminates for nonlinear optics>> <Homogeneity> To evaluate the homogeneity of the electro-optical polymer layer in the nonlinear optical laminate, the nonlinear optical laminate of Sample 1 was observed under a microscope. An example of a bright-field microscope image of the nonlinear optical laminate of Sample 1 is shown in Figure 7, and an example of a dark-field microscope image is shown in Figure 8. Defect structures such as cracks can be observed more clearly in the dark-field microscope image. No defect structures such as cracks were observed in either the bright-field or dark-field microscope images of the nonlinear optical laminate of Sample 1, confirming the production of a nonlinear optical laminate with excellent homogeneity. Note that the white spots seen in the dark-field microscope image of the nonlinear optical laminate of Sample 1 are due to deposits, not defect structures. As a comparative example, an example of a bright-field microscope image of the nonlinear optical laminate of Sample 101 is shown in Figure 9. Defect structures such as cracks were observed in the bright-field microscope image of the nonlinear optical laminate of Sample 101, which was prepared by mechanical tensile peeling. In addition, having excellent homogeneity means that the nonlinear optical laminate can be produced with a good yield, since defective structures such as cracks are less likely to occur in the nonlinear optical laminate.

[0097] <Non-damaging> To evaluate the non-damage resistance of the electro-optic polymer contained in the electro-optic polymer layer in the non-linear optical laminate, the absorption spectra of the non-linear optical laminates of Sample 2 and Sample 102 were measured. For the absorption spectrum measurement, a synthetic quartz glass substrate with a very small absorption coefficient at each wavelength was used as the target substrate for Sample 2 and Sample 102. An ultraviolet-visible-near-infrared spectrophotometer (UH4150, manufactured by Hitachi High-Tech Corporation) was used to measure the absorption spectrum. Figure 10 shows the absorption spectrum of the non-linear optical laminate of Sample 102 (Reference Example). Figure 11 shows the absorption spectrum of the non-linear optical laminate of Sample 2. The shape and intensity of the absorption spectra of the non-linear optical laminate of Sample 2 and the non-linear optical laminate of Sample 102 (Reference Example) were almost identical, confirming that the electro-optic polymer (including the electro-optic molecules) in the non-linear optical laminate of Sample 2 was not damaged and that a non-linear optical laminate with excellent non-damage resistance was produced. This indicates that the electro-optic polymer (including electro-optic molecules) contained in the electro-optic polymer layer is not damaged even by the fifth step, which includes laser irradiation, and other steps (steps 1, 2, 3, 4, and 6). For Sample 2, a very small "voltage per unit thickness of the electro-optic polymer layer" (0.01 V / μm) was applied in the poling treatment (step 2), as shown in Table 1, to eliminate the effect of changes in spectral intensity due to the orientation of the electro-optic molecules caused by poling the electro-optic polymer layer. Having excellent damage resistance means that the nonlinear optical properties of the nonlinear optical laminate are less likely to deteriorate due to damage to the electro-optic polymer (including the electro-optic molecules). This means that it is possible to manufacture nonlinear optical laminates with excellent nonlinear optical properties with high yield.

[0098] <Nonlinear optical properties> In order to evaluate the nonlinear optical properties (electro-optical properties) of the electro-optical polymer layer in the nonlinear optical laminate, the electro-optical coefficient of the nonlinear optical laminate relating to Sample 3 was evaluated. To measure the electro-optical coefficient, a glass substrate (ITO glass substrate) having a transparent electrode was used as the target substrate for Sample 3. An IZO film having a thickness of 100 nm was formed by RF sputtering on the surface of the nonlinear optical laminate relating to Sample 3 on the side of the electro-optical polymer layer. The electro-optical coefficient (r 33 ) was calculated from the "electro-optic coefficient at a wavelength of 1308 nm after the sixth step (r 33 ) [pm / V]" and "Electro-optic coefficient at wavelength 1550 nm after the 6th step (r 33 ) [pm / V]" column. For Sample 3, as shown in Table 1, there was almost no difference in the electro-optic coefficient after Step 2 and Step 6. This confirms that the nonlinear optical laminate of Sample 3 did not experience a decrease in its nonlinear optical properties (electro-optic properties), and thus a nonlinear optical laminate with excellent nonlinear optical properties (electro-optic properties) was produced. This indicates that the electro-optic polymer (including electro-optic molecules) contained in the electro-optic polymer layer is not damaged by Step 5, which includes laser irradiation, and other steps (Steps 3, 4, and 6), and that the orientation relaxation of the electro-optic molecules due to temperature rise does not occur. Having excellent nonlinear optical properties (electro-optic properties) means that nonlinear optical laminates with excellent nonlinear optical properties (electro-optic properties) can be produced with a high yield, since damage to the electro-optic polymer (including electro-optic molecules) and a decrease in the nonlinear optical properties due to the orientation relaxation of the electro-optic molecules are unlikely to occur in the nonlinear optical laminate.

[0099] <Fabrication of optical waveguide devices> An optical waveguide device was fabricated using the nonlinear optical laminate of Sample 4. A mask was formed on the electro-optic polymer layer of the nonlinear optical laminate of Sample 4 by photolithography. The electro-optic polymer layer was then processed by dry etching using a reactive ion etching apparatus to create a ridge-type electro-optic polymer optical waveguide structure. A UV-curable resin (FE4048, manufactured by NTT-AT Corporation) was applied by spin coating to the waveguide-processed electro-optic polymer layer as the upper cladding layer of the optical waveguide. The upper cladding layer was then irradiated with 365 nm LED light and then heat-treated at 80°C. A SiO2 layer was then formed on the upper cladding layer by chemical vapor deposition (CVD) at 80°C, yielding the "optical waveguide device of Sample 4." Figure 12 shows an electron microscope (reflection electron microscope) image of the cross section of the optical waveguide device of Sample 4 obtained by dicing with a diamond blade. In Figure 12, the structure of the ridge-type electro-optic polymer optical waveguide on the cycloolefin polymer (ZEONOR (Zeon Corporation, registered trademark)) that was the outermost layer of the target substrate can be seen. Next, the propagation loss of the electro-optic polymer optical waveguide in the optical waveguide device of Sample 4 was evaluated. The optical waveguide device of Sample 4 was diced to have an optical waveguide length of 7 mm, and a continuous wave laser beam with a wavelength of 1535 nm and an output of 7.3 mW was irradiated onto one end face of the waveguide with an irradiation spot diameter (1 / e 2 ) and an irradiation spot diameter of 2 μm (1 / e 2When light was extracted using a tapered lensed fiber with a 1000 Ω resistivity (1.0 Ω / s), the output light power was 1.6 mW. The coupling loss of the tapered lensed fiber to the optical waveguide, estimated by the cutback method, was 4 dB (2 dB on one side), and the estimated propagation loss of the optical waveguide was 3.7 dB / cm. This value is close to the optical loss (approximately 3 dB / cm) of the electro-optic polymer material used at a wavelength of 1550 nm. The fabricated electro-optic polymer optical waveguide exhibited low loss, confirming the production of a nonlinear optical laminate with excellent homogeneity and no defect structures such as cracks. As mentioned above, excellent homogeneity means that nonlinear optical laminates can be manufactured with high yield, since defect structures such as cracks are less likely to occur in the nonlinear optical laminate.

[0100] The methods for manufacturing the nonlinear optical laminates of Samples 1 to 4 correspond to Examples. The method for manufacturing the nonlinear optical laminate of Sample 101 corresponds to Comparative Example. It was found that the methods for manufacturing the nonlinear optical laminates of Samples 1 to 4 can manufacture the nonlinear optical laminates with a higher yield than the method for manufacturing the nonlinear optical laminate of Sample 101.

[0101] From the above, it was confirmed that the method for producing the nonlinear optical laminate according to Samples 1 to 4 is capable of producing the nonlinear optical laminate with a good yield.

[0102] Although the embodiments and examples of the present invention have been described above, it is also planned from the beginning that the configurations of the above-described embodiments and examples may be appropriately combined.

[0103] The embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the above-described embodiments and examples, and it is intended to include any modifications within the scope of the claims that are equivalent to the claims. [Explanation of symbols]

[0104] 1 Support substrate, 2 Light absorption layer, 3 First electrode, 4 Electro-optic polymer layer, 5 Second electrode, 6 Target substrate, 7a First charge blocking layer, 7b Second charge blocking layer, 8 Sealing film layer, 11 First laminate, 12 Second laminate, 13 Third laminate, 14 Fourth laminate, 20 Nonlinear optical laminate.

Claims

1. A method for manufacturing a nonlinear optical laminate, comprising: a target substrate; and an electro-optic polymer layer located on the target substrate, the method comprising: a first step of preparing a first laminate in which a support substrate, a light absorbing layer, a first electrode, an electro-optical polymer layer, and a second electrode are laminated in this order; a second step of performing a poling treatment on the electro-optic polymer layer of the first laminate; a third step of removing the second electrode from the first laminate to obtain a second laminate; a fourth step of stacking the target substrate on the surface of the second stack that was in contact with the second electrode, thereby obtaining a third stack; a fifth step of removing the support substrate from the third laminate by laser peeling, thereby obtaining a fourth laminate; and a sixth step of removing the light absorbing layer and the first electrode from the fourth stack to obtain a nonlinear optical stack, in this order.

2. 2. The method for producing a nonlinear optical laminate according to claim 1, wherein the light absorbing layer is made of a first resin.

3. 3. The method for producing a nonlinear optical laminate according to claim 2, wherein the glass transition temperature of the first resin is higher than the glass transition temperature of the electro-optic polymer layer.

4. 4. The method for producing a nonlinear optical laminate according to claim 2, wherein the heat distortion temperature of the first resin is higher than the glass transition temperature of the electro-optic polymer layer.

5. 4. The method for producing a nonlinear optical laminate according to claim 2, wherein the first resin is polyimide.

6. 4. The method for producing a nonlinear optical laminate according to claim 1, wherein in the first laminate, a first charge blocking layer is further laminated between the first electrode and the electro-optical polymer layer.

7. 7. The method for producing a nonlinear optical laminate according to claim 6, wherein in the sixth step, the first charge blocking layer is further removed from the fourth laminate.

8. 4. The method for producing a nonlinear optical laminate according to claim 1, wherein a second charge blocking layer is further laminated between the electro-optic polymer layer and the second electrode in the first laminate.

9. 9. The method for producing a nonlinear optical laminate according to claim 8, wherein in the third step, the second charge blocking layer is further removed from the first laminate.

10. In the fourth step, a sealing film layer is further laminated between the second laminate and the target substrate, 4. The method for producing a nonlinear optical laminate according to claim 1, further comprising the sealing film layer located between the target substrate and the electro-optic polymer layer.

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