Mold for optical waveguide, manufacturing method for optical waveguide, and optical waveguide

Abstract

The object of the present invention is to provide an optical waveguide having small swells in a transfer section and small residual film in an entrance section and an exit section, an optical waveguide mold for producing the same, and a method for producing the optical waveguide. The mold for optical waveguide is formed of a transparent substrate 4 and a resin 5, and is used to manufacture an optical waveguide consisting of a transfer section 1, an incident section 2, and an exit section 3. The mold for optical waveguide has a flat transfer section pattern 61 for forming the transfer section 1 in the resin 5, and either or both of an incident section pattern 62 for forming the incident section 2 and an exit section pattern 63 for forming the exit section 3. If the depth of the concave portion of the incident section pattern 62 or the exit section pattern 63 is B, the fill factor of the convex portion is FF, and the difference in height between the incident section pattern 62 or the exit section pattern 63 and the transfer section pattern 61 is D, then the following formula can be expressed: The relationship 0.9×B×(1-FF)≦D≦1.1×B×(1-FF) is satisfied.

Description

[Technical field]

[0001] The present invention relates to a mold for an optical waveguide, a method for manufacturing an optical waveguide, and an optical waveguide. [Background technology]

[0002] Waveguides for AR (Augmented Reality) glasses, which are expected to have a large market, are being actively developed with high refractive index resin materials to obtain high viewing angle performance and various input / output coupler structures to achieve high image transfer efficiency and uniform output. Optical waveguides are used in various electronic devices because they are lightweight and capable of high-speed signal transmission. In recent years, pattern formation technology using imprinting has been attracting attention for such optical waveguides, instead of photolithography technology (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2016-207717 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] However, when creating an optical waveguide using the imprint method, if the gaps in the transfer part pattern of the mold are large, there is a problem that undulations occur in the transfer part of the waveguide, reducing efficiency and causing color shifts. Therefore, if the resin film thickness is increased to fill the gaps, the remaining film under the patterns of the entrance and exit parts becomes large, which causes a problem of reducing efficiency on the wide-angle side.

[0005] Therefore, an object of the present invention is to provide an optical waveguide having small swells in the transfer section and small residual film in the input and output sections, an optical waveguide mold for manufacturing the optical waveguide, and a method for manufacturing the optical waveguide. [Means for solving the problem]

[0006] In order to achieve the above object, the optical waveguide mold of the present invention is an optical waveguide mold for manufacturing an optical waveguide, which is formed of a transparent substrate and a resin formed on a surface of the transparent substrate, and which comprises a transfer section for transferring light, an incident section for making light incident on the transfer section, and an exit section for making the light exit from the transfer section, and which has a flat transfer section pattern for forming the transfer section in the resin, and at least one or both of an incident section pattern for forming the incident section in the resin and an exit section pattern for forming the exit section in the resin, and wherein, where B is the depth of a concave portion of the incident section pattern or the exit section pattern, FF is the fill factor of a convex portion, and D is the difference in height between the incident section pattern or the exit section pattern and the transfer section pattern, the following formula is satisfied: 0.9×B×(1-FF)≦D≦1.1×B×(1-FF) The present invention is characterized in that:

[0007] In this case, it is preferable to satisfy D=B×(1−FF).

[0008] The optical waveguide mold of the present invention is an optical waveguide mold for manufacturing an optical waveguide, which is formed of a transparent substrate and a resin formed on a surface of the transparent substrate, and which comprises a transfer section for transferring light, an incident section for making light incident on the transfer section, and an exit section for making the light exit from the transfer section, and which has a flat transfer section pattern for forming the transfer section in the resin, an incident section pattern for forming the incident section in the resin, and an exit section pattern for forming the exit section in the resin, and wherein, when the depth of the concave portion of the incident section pattern is B1, the fill factor of the convex portion is FF1, the depth of the concave portion of the exit section pattern is B2, the fill factor of the convex portion is FF2, the difference in height between the incident section pattern and the transfer section pattern is D1, and the difference in height between the exit section pattern and the transfer section pattern is D2, the following formula can be expressed: 0.9×B1×(1-FF1)≦D1≦1.1×B1×(1-FF1) 0.9×B2×(1-FF2)≦D2≦1.1×B2×(1-FF2) The present invention is characterized in that:

[0009] In this case, D1=D2 may be satisfied, and B1-D1=B2-D2 may be satisfied.

[0010] Also, D1 = B1 × (1-FF1) D2 = B2 × (1-FF2) It is preferable to satisfy the following.

[0011] The optical waveguide mold of the present invention is formed of a transparent substrate and a resin formed on the surface of the transparent substrate, and is configured to include a first transfer section and a second transfer section for transferring light, an entrance section for making light incident on the first transfer section, an expansion section disposed between the first transfer section and the second transfer section for expanding an exit pupil and controlling the light incident from the first transfer section to the second transfer section, and an exit section for making the light exit from the second transfer section, and the optical waveguide mold includes a flat first transfer section pattern for forming the first transfer section in the resin, a flat second transfer section pattern for forming the second transfer section in the resin, and the entrance section is formed in the resin. a pattern for an incident portion for forming the light emitting portion in the resin, a pattern for an emission portion for forming the light emitting portion in the resin, and a pattern for an enlarged portion for forming the enlarged portion in the resin, wherein the depth of the concave portion of the pattern for the incident portion is B1, the fill factor of the convex portion is FF1, the depth of the concave portion of the pattern for the emission portion is B2, the fill factor of the convex portion is FF2, the depth of the concave portion of the pattern for the enlarged portion is B3, and the fill factor of the convex portion is FF3, then a difference D1 in height between the pattern for the incident portion and the pattern for the first transfer portion, a difference D2 in height between the pattern for the emission portion and the pattern for the second transfer portion, and a difference D3 in height between the pattern for the enlarged portion and the pattern for the first transfer portion or the pattern for the second transfer portion are expressed by the following formulas: 0.9×B1×(1-FF1)≦D1≦1.1×B1×(1-FF1) 0.9×B2×(1-FF2)≦D2≦1.1×B2×(1-FF2) 0.9×B3×(1-FF3)≦D3≦1.1×B3×(1-FF3) The present invention is characterized in that:

[0012] In this case, D1=D2=D3 may be satisfied, and B1-D1=B2-D2=B3-D3 may be satisfied.

[0013] Also, D1 = B1 × (1-FF1) D2 = B2 × (1-FF2) D3 = B3 × (1-FF3) It is preferable to satisfy the following.

[0014] The method for producing an optical waveguide of the present invention is characterized in that imprint molding is carried out using the above-mentioned mold for an optical waveguide.

[0015] The refractive index of the resin is preferably 1.8 or more.

[0016] Moreover, the imprint molding is preferably performed so that the thickness of a residual resin film formed by at least one of the incident portion pattern, the exit portion pattern, and the magnification portion pattern is 100 nm or less.

[0017] The optical waveguide of the present invention is an optical waveguide comprising a transparent substrate and a resin formed on a surface of the transparent substrate, the optical waveguide comprising: a transfer section for transferring light, the transfer section being made of the transparent substrate and the resin formed flat on the surface of the transparent substrate; an entrance section being made of resin formed as a grating pattern on the surface of the transparent substrate for making light incident on the transfer section; and an exit section being made of resin formed as a grating pattern on the surface of the transparent substrate for making the light exit from the transfer section, the height of the convex portions of the grating pattern of the entrance section being b1, the fill factor of the convex portions being ff1, the thickness of the residual film being d1, the height of the convex portions of the grating pattern of the exit section being b2, the fill factor of the convex portions being ff2, and the thickness of the residual film being d2, the thickness t of the resin of the transfer section being given by the following formula: 0.9×(d1+b1×ff1)≦t≦1.1×(d1+b1×ff1) 0.9×(d2+b2×ff2)≦t≦1.1×(d2+b2×ff2) The present invention is characterized in that:

[0018] In this case, d1=d2 may be satisfied, or b1+d1=b2+d2 may be satisfied.

[0019] It is also preferable to satisfy t=d1+b1×ff1=d2+b2×ff2.

[0020] Further, an optical waveguide of the present invention is an optical waveguide comprising a transparent substrate and a resin formed on a surface of the transparent substrate, the optical waveguide comprising the transparent substrate and a resin formed flat on the surface of the transparent substrate, a first transfer section and a second transfer section for transferring light, and a resin formed as a grating pattern on the surface of the transparent substrate, an incident section for making light incident on the first transfer section, and a resin disposed between the first transfer section and the second transfer section, the resin formed as an enlargement pattern on the surface of the transparent substrate, and a light guide section for controlling the light incident from the first transfer section to output to the second transfer section in order to enlarge an exit pupil. the height of the convex portions of the grating pattern of the entrance portion is b1, the fill factor of the convex portions is ff1, the thickness of the residual film is d1, the height of the convex portions of the grating pattern of the exit portion is b2, the fill factor of the convex portions is ff2, the thickness of the residual film is d2, the height of the convex portions of the enlargement pattern of the entrance portion is b3, the fill factor of the convex portions is ff3, and the thickness of the residual film is d3, the thickness t of the resin of the first transfer portion and the second transfer portion is expressed by the following formula: 0.9×(d1+b1×ff1)≦t≦1.1×(d1+b1×ff1) 0.9×(d2+b2×ff2)≦t≦1.1×(d2+b2×ff2) 0.9×(d3+b3×ff3)≦t≦1.1×(d3+b3×ff3) The present invention is characterized in that:

[0021] In this case, d1=d2=d3 may be satisfied, or b1+d1=b2+d2=b3+d3 may be satisfied.

[0022] It is also preferable to satisfy t=d1+b1×ff1=d2+b2×ff2=d3+b3×ff3.

[0023] The refractive index of the resin is preferably 1.8 or more.

[0024] Furthermore, it is preferable that the thickness of the remaining film of at least one of the grating patterns in the entrance portion and the exit portion and the expansion pattern in the expansion portion is 100 nm or less. Effect of the Invention

[0025] It is possible to provide a waveguide having small swells in the transfer section and small residual film at the entrance and exit sections, an optical waveguide mold for producing the waveguide, and a method for producing an optical waveguide. [Brief description of the drawings]

[0026] [Figure 1] FIG. 2 is a schematic cross-sectional view showing the configuration of an optical waveguide. [Diagram 2] FIG. 13 is a diagram showing the relationship between the refractive index of a substrate and diffraction efficiency. [Diagram 3] FIG. 13 is a diagram showing the relationship between the thickness of the residual film and the diffraction efficiency. [Figure 4] 1A to 1C are diagrams showing a conventional method for manufacturing an optical waveguide using a mold. [Diagram 5] 1A to 1C are diagrams illustrating a conventional method for manufacturing another optical waveguide using a mold. [Figure 6] 1 is a diagram showing the state of a flat portion of an optical waveguide manufactured using a conventional mold. [Figure 7] 1A to 1C are diagrams showing still another conventional method for manufacturing an optical waveguide using a mold. [Figure 8] 1A to 1C are schematic cross-sectional views showing a method for producing an optical waveguide of the present invention. [Figure 9]11A and 11B are diagrams for explaining filling of resin due to bending of a mold. [Figure 10] FIG. 13 is a diagram illustrating the conditions for filling without leaving voids due to bending. [Figure 11] FIG. 13 is a diagram illustrating the limit value at which a mold is deflected by pressure. [Figure 12] FIG. 13 is a diagram showing the filling conditions in a mold when the flat portion length is 3 mm. [Figure 13] FIG. 13 is a diagram showing the filling conditions in a mold when the flat portion length is 2 mm. [Figure 14] 1A to 1C are schematic cross-sectional views showing a method for producing an optical waveguide of the present invention. [Figure 15] 1A to 1C are schematic cross-sectional views showing a method for producing an optical waveguide of the present invention. [Figure 16] 1 is a schematic perspective view showing an optical waveguide having an enlarged portion according to the present invention; [Figure 17] 1A to 1C are schematic cross-sectional views showing a method for producing an optical waveguide of the present invention. [Figure 18] 1A to 1C are schematic cross-sectional views showing a method for producing an optical waveguide of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] 1, the optical waveguide is made of a transparent substrate 4 and a resin 5 formed on the surface of the transparent substrate 4. The optical waveguide is mainly made up of a transfer section 1, an input section 2, and an output section 3.

[0028] The transfer section 1 is for transferring light and is made of a transparent substrate 4 and a resin 5 formed flat on the surface of the transparent substrate 4. The light incident from the input section 2 is transferred while being totally reflected by the transfer section 1, and is emitted from the output section 3.

[0029] The incident section 2 is made of resin 5 formed as a grating pattern on the surface of a transparent substrate 4, and is used to make light incident on the transfer section 1. The grating pattern may have any shape as long as it can make light incident on the transfer section 1. For example, it can diffract light so that it travels through the transfer section 1 by total reflection, and can be a line-and-space pattern in which inclined convex sections are periodically arranged.

[0030] The emission section 3 is made of resin 5 formed as a grating pattern on the surface of the transparent substrate 4, and is for emitting light from the transfer section 1. The grating pattern may have any shape as long as it can emit light from the transfer section 1, but for example, it can diffract light so that it is emitted to the outside from the transparent substrate 4, and can be a line-and-space pattern in which inclined convex portions are periodically arranged.

[0031] A simulation was performed on this type of optical waveguide. The pitch of the grating pattern at the entrance was 420 nm, the height of the inclined convex portion was 350 nm, the width was 210 nm, and the angle was 55 degrees. The wavelength of the incident light was 630 nm. Figure 2 shows the relationship between the angle of incidence for each refractive index of the transparent substrate 4 and the diffraction efficiency of the entrance portion 2. As shown in Figure 2, it can be seen that the higher the refractive index, the higher the diffraction efficiency can be obtained at a wider angle of incidence. For this reason, a high refractive index material is required for the material of the optical waveguide. Specifically, it is preferable that the refractive index of the transparent substrate 4 and the resin 5 is 1.8 or more.

[0032] In addition, when the grating pattern is created by the imprint method, a residual film 51 is generated under the pattern. If there is no difference in refractive index between the transparent substrate 4 and the resin 5, there is no effect of the residual film, but currently, the refractive index of the substrate is higher than that of the resin 5, with the refractive index of the substrate being 2.0 and the refractive index of the resin 5 being 1.9, which is a difference of about 0.1. In addition, it is expected that the relationship between the refractive index of the substrate and the resin 5 will remain such that the refractive index of the substrate is higher than that of the resin 5 even if the refractive index of the material is improved in the future. Therefore, a simulation was performed to see how the diffraction efficiency of the incident part 2 is affected by the difference in the thickness of the residual film 51 when the grating pattern of the incident part 2 has the residual film 51. The pitch of the grating pattern of the incident part was 420 nm, the height of the inclined convex part was 350 nm, the width was 210 nm, and the angle was 55 degrees. The wavelength of the incident light was 630 nm. The refractive index of the substrate, the refractive index of the resin 5, and the thickness of the residual film 51 used in the simulation are shown in Table 1 and Figure 3(a). [Table 1] The results are shown in Figure 3(b).

[0033] As a result of the simulation, when a grating pattern with a refractive index of 1.9 was placed on a substrate with a refractive index of 2.0, an incident angle of ±30° was obtained. However, it was found that as the residual film 51 becomes thicker, the efficiency on the wide-angle side decreases, so it is preferable to keep the residual film 51 at 30 nm or less. Furthermore, it was also confirmed by the simulation that when the refractive index of the resin 5 increases to 1.95, the efficiency on the wide-angle side can be maintained if the residual film 51 is 100 nm or less.

[0034] Here, we consider the case where the grating patterns of the incident portion 2 and the exit portion 3 of the optical waveguide and the flat portion of the transfer portion 1 are molded in resin 5 on a transparent substrate 4 by the imprint method. As shown in Fig. 4, the optical waveguide mold 6 used in the imprint method is mainly composed of a transfer portion pattern 61 and at least one or both of an incident portion pattern 62 and an exit portion pattern 63. The material of the optical waveguide mold 6 may be any material that can be used in the imprint method, and for example, glass or resin can be used.

[0035] The transfer portion pattern 61 is a flat pattern for forming the flat portion of the transfer portion 1 in the resin 5 .

[0036] The pattern for the incident portion 62 is for forming the incident portion 2 in the resin 5. The pattern for the incident portion 62 may be of any type as long as it can form the incident portion 2 in the resin 5, but for example, it may be a pattern that is an inversion of the grating pattern of the incident portion 2 described above.

[0037] The pattern 63 for the emission portion is for forming the emission portion 3 in the resin 5. The pattern 63 for the emission portion may be any pattern as long as it can form the emission portion 3 in the resin 5, but for example, it may be a pattern obtained by inverting the grating pattern of the emission portion 3 described above.

[0038] Fig. 4(a) is a diagram showing the state of resin 5 during molding when the thickness of resin 5 applied onto transparent substrate 4 before imprint molding is thick. If the thickness of resin 5 before molding is thick, when resin 5 is pressed by optical waveguide mold 6, as shown in Figs. 4(b) and (c), resin 5 tends to move laterally from the grating pattern side to the flat portion side, making molding possible, but as shown in Fig. 4(d), residual film 51 becomes thick.

[0039] Conversely, Fig. 5(a) is a diagram showing the state of resin 5 during molding when the thickness of resin 5 applied to transparent substrate 4 before imprint molding is thin. If the thickness of resin 5 before molding is thin, when resin 5 is pressed by optical waveguide mold 6, it becomes difficult for resin 5 to move laterally from the grating pattern side to the flat portion side, as shown in Figs. 5(b) and (c), and voids 9 remain after molding, causing undulations in the flat portion, as shown in Figs. 5(d) and 6.

[0040] 7(a) is a diagram showing the state of resin 5 during molding when the voids in transfer pattern 61 of optical waveguide mold 6 are eliminated so that no voids 9 remain after molding. If the voids in transfer pattern 61 of optical waveguide mold 6 are eliminated, when resin 5 is pressurized by optical waveguide mold 6, resin 5 moves laterally from the transfer pattern 61 side to the grating pattern side as shown in Figures 7(b) and (c), and therefore the residual film 51 of the grating pattern becomes thicker after molding as shown in Figure 7(d).

[0041] Therefore, in view of the above, if it is desired to thin the residual film 51 of the grating pattern, it is desirable to form the transfer section 1, the input section 2 and the output section 3 in a manner that minimizes lateral movement of the resin 5 when the resin 5 is pressurized by the optical waveguide mold 6.

[0042] Hereinafter, the optical waveguide mold 6 of the present invention will be described, which is unlikely to cause lateral movement of the resin 5 when the resin 5 is pressurized by the optical waveguide mold 6. The optical waveguide mold 6 of the present invention is formed by a transparent substrate 4 and a resin 5 formed on the surface of the transparent substrate 4, and is intended for manufacturing an optical waveguide including a transfer section 1 for transferring light, an incident section 2 for making light incident on the transfer section 1, and an exit section 3 for making the light exit from the transfer section 1. As described above, the optical waveguide mold 6 is mainly composed of a transfer section pattern 61 and at least one or both of an incident section pattern 62 and an exit section pattern 63. The material of the optical waveguide mold 6 may be any material that can be used for imprinting, and may be, for example, a well-known material such as glass.

[0043] Here, in order to prevent the resin 5 from moving laterally when the resin 5 is pressurized by the optical waveguide mold 6, it is only necessary to balance the volume per unit space of the gap (recess) of the pattern for incident portion 62 or the pattern for emission portion 63 with the gap of the pattern for transfer portion 61 adjacent to the pattern for incident portion 62 or the pattern for emission portion 63. Specifically, as shown in Fig. 8(a), assuming that the pitch of the pattern for incident portion 62 or the pattern for emission portion 63 is P, the depth of the recess is B, the fill factor of the protrusion is FF, and the difference in height between the pattern for incident portion 62 or the pattern for emission portion 63 and the pattern for transfer portion 61 is D, it is preferable that P x D = P x B x (1 - FF), that is, D = B x (1 - FF).

[0044] Here, the fill factor of the convex portion means the ratio of the area of ​​the convex portion to the area of ​​the pattern surface when viewed from the side of the surface (hereinafter referred to as the pattern surface) on which the pattern for the incident portion 62, the pattern for the emission portion 63, etc. of the optical waveguide mold 6 are located. The depth of the concave portion means, in other words, the height of the top of the convex portion relative to the bottom of the concave portion. When the depth of the concave portion of the pattern varies, the average depth of the entire concave portion of each pattern may be used. The difference in height between the pattern for the incident portion 62 or the pattern for the emission portion 63 and the pattern for the transfer portion 61 means, in other words, the height of the top of the convex portion of the pattern for the incident portion 62 or the pattern for the emission portion 63 relative to the flat surface of the pattern for the transfer portion 61, as shown in FIG. 8(a).

[0045] Even if D=B×(1-FF) is not satisfied and the volume per unit space of the void is not balanced, it is possible to mold the mold for optical waveguide 6 by bending the resin 5 side or the opposite side in a convex shape if there is a small error. Specifically, as shown in FIG. 9(a), the resin 5 at the bottom of the pattern for the entrance part 62 and the pattern for the exit part 63 moves due to pressure, and the filling part spreads near the pattern, and the void 9 in the pattern for the transfer part 61 becomes narrow. When further pressure is applied, the mold for optical waveguide 6 bends and pushes the resin 5 to the periphery as shown in FIG. 9(b). At this time, if the bending of the mold for optical waveguide 6 is small, the void 9 remains, but if the bending is sufficient, the resin 5 pushed at the center can fill the voids around it as shown in FIG. 9(c).

[0046] Therefore, it is preferable that the error in the volume per unit space between the voids is at least 10% or less. In this case, the following formula 0.9×B×(1-FF)≦D≦1.1×B×(1-FF) Of course, the smaller the error, the better, and it is preferably 5% or less, and more preferably 3% or less.

[0047] As a result, when the resin 5 is pressurized by the optical waveguide mold 6, as shown in Figures 8(b) and (c), the resin 5 hardly moves laterally. Therefore, as shown in Figure 8(d), the remaining film 51 of the grating pattern after molding can be made thin, and the transfer section 1 can be made into an excellent shape without swells or voids 9.

[0048] We will now consider the conditions under which the optical waveguide mold 6 can be molded without leaving any voids 9 due to bending. First, as shown in Fig. 10, the area of ​​the resin 5 pushed aside by the bending of the optical waveguide mold 6 is Y, and the area of ​​the gap at the end of the optical waveguide mold 6 after bending is Z. If the radius of curvature of the deflection is approximated as R, the maximum depth when the resin 5 is pushed aside is x, the height of the gap is s', the angle from the vertical line to the boundary point between the resin 5 and the gap is α, and the angle from the vertical line to the point of the maximum height of the gap is θ, then Y=R 2 (α-cosαsinα) *Area αR of a sector with radius R and angle 2α 2 and the area R of a triangle whose height is Rcosα and whose base length is 2Rsinα. 2 Difference from cosαsinα *cosα=cosθ+(s' / R) Z≒s'(a-Rsinα) / 2 *The area of ​​a triangle with a base length of a-Rsinα and height of s' Here, the condition for the optical waveguide mold 6 to be bent and filled without leaving any voids is when Y=2Z, and therefore the following formula (1) is established. R 2 (α-cosαsinα)=s'(a-Rsinα)...Equation (1)

[0049] In addition, the limit value for the deflection of the optical waveguide mold 6 due to pressure can be expressed by the following formula (2) based on a model of a double-supported beam subjected to uniform pressure p as shown in Figure 11, where R' is the radius of curvature, L is the length of the beam, and δ is the magnitude of deflection in the vertical direction. R' = (L / 2) 2 / (2δ)...Equation (2) ※δ=5pL 4 / (384EI) I=g 3 / 12 E: Young's modulus of the optical waveguide mold g: Thickness of the optical waveguide mold

[0050] Therefore, the mold can be bent until the gap is completely filled only when the radius of curvature R of the filling condition is equal to or greater than the radius of curvature R' that bends under pressure (R ≧ R'). However, the coating thickness t must be thicker than the depth χ of the beam to fill the gap.

[0051] Fig. 12 is a diagram showing the relationship between the height s' of the gap 9 between the resin 5 and the optical waveguide mold 6, calculated based on formula (1), and the radius of curvature R due to the bending of the optical waveguide mold 6 required to fill the resin 5 without leaving any gaps. The dashed lines (1) to (5) in Fig. 12 indicate the value of the radius of curvature R' calculated based on formula (2) from the differential pressure applied to both sides of the optical waveguide mold 6 during imprint molding and the thickness of the optical waveguide mold 6. The thickness g of the transfer portion pattern 61 of the optical waveguide mold and the pressure p are as follows: Dashed line (1) g: 0.7 mm, p: 0.25 MPa Dashed line (2) g: 0.7 mm, p: 0.5 MPa Dashed line (3) g: 0.7 mm, p: 0.75 MPa Dashed line (4) g: 0.5 mm, p: 0.25 MPa Dashed line (5) g: 0.5 mm, p: 0.5 MPa The width L of the transfer portion pattern 61 of the optical waveguide mold was set to 3 mm. The material of the optical waveguide mold was glass with a Young's modulus E of 73.6 GPa.

[0052] Since the radius of curvature R' is proportional to the cube of the thickness α of the transfer portion pattern 61 of the waveguide mold, by changing the thickness α from 0.7 mm to 0.5 mm, a bending with a radius of curvature sufficient for filling by pressure can be achieved.

[0053] We also investigated the case where the width L of the transfer pattern 61 of the optical waveguide mold was set to 2 mm. Fig. 13 is a diagram showing the relationship between the height s' of the gap between the resin 5 and the optical waveguide mold 6, calculated based on formula (1), and the radius of curvature R due to the bending of the optical waveguide mold 6 required to fill the resin 5 without gaps. The dashed lines (1) to (4) in Fig. 13 indicate the value of the radius of curvature R' calculated based on formula (2) from the pressure difference applied to both sides of the optical waveguide mold 6 during imprint molding and the thickness of the optical waveguide mold 6. The thickness g and pressure p of the transfer pattern 61 of the optical waveguide mold are as follows. Dashed line (1) g: 0.7 mm, p: 0.75 MPa Dashed line (2) g: 0.7 mm, p: 1.5 MPa Dashed line (3) g: 0.7 mm, p: 2 MPa Dashed line (4) g: 0.7 mm, p: 0.1 MPa The material of the optical waveguide mold was glass with a Young's modulus E of 73.6 GPa for the dashed lines (1) to (3), and polyethylene terephthalate (PET) with a Young's modulus E of 4 GPa for the dashed line (4).

[0054] As shown in Fig. 13, when the width L is set to 2 mm, the deflection of the optical waveguide mold must be increased in order to fill the gap without gaps, making filling even more difficult. Even if the pressure is 2 MPa, the gap must be 50 nm or less to fill the gap, and it is almost impossible to fill the gap by deflection alone. Therefore, it is important to balance the volume per unit space of the gap (recess) of the incident part pattern 62 or the emission part pattern 63 and the gap of the transfer part pattern 61 adjacent to the incident part pattern 62 or the emission part pattern 63. Note that, within the range where filling is possible, the necessary coating film thickness t is 27 nm or more for the indentation depth x at a gap of 50 nm, so there is almost no need to consider the effect of the film thickness t.

[0055] Next, the method for manufacturing an optical waveguide of the present invention will be described with reference to Fig. 8. The method for manufacturing an optical waveguide of the present invention is a method for manufacturing an optical waveguide formed of a transparent substrate 4 and a resin 5 formed on the surface of the transparent substrate 4, and comprising a transfer section 1 for transferring light, an incident section 2 for making light incident on the transfer section 1, and an exit section 3 for making light exit from the transfer section 1, and is performed by imprint molding using the optical waveguide mold 6 of the present invention described above. As described above, the optical waveguide mold 6 satisfies at least 0.9×B×(1-FF)≦D≦1.1×B×(1-FF), preferably 0.95×B×(1-FF)≦D≦1.05×B×(1-FF), and more preferably 0.97×B×(1-FF)≦D≦1.03×B×(1-FF), where P is the pitch of the incident portion pattern 62 or the emission portion pattern 63, B is the depth of the recessed portion, FF is the fill factor of the protruding portion, and D is the depth of the transfer portion pattern 61 adjacent to the incident portion pattern 62 or the emission portion pattern 63. Most preferably, D=B×(1-FF) is satisfied.

[0056] First, the resin 5 is applied to the surface of the transparent substrate 4. The resin 5 may be any transparent resin that can be used in imprint molding, such as a photocurable resin, a thermosetting resin, or a thermoplastic resin. Specifically, an acrylic photocurable resin may be used. The resin 5 may be applied to the transparent substrate 4 by a well-known method such as a spin coater. The refractive index of the resin 5 is preferably 1.8 or more.

[0057] Next, at least one or both of the incident part 2 and the exit part 3 constituting the grating pattern and the transfer part 1 constituting the flat surface are transferred to the photocurable resin by the imprint method using the optical waveguide mold 6. Specifically, as shown in Figs. 8(b) and (c), the optical waveguide mold 6 is pressed against the flowable resin 5 on the transparent substrate 4, and the resin 5 is filled into the transfer part pattern 61, the incident part pattern 62, and the exit part pattern 63. At this time, it is preferable to pressurize the optical waveguide mold 6 until the thickness d of the residual film 51 of the resin 5 becomes 100 nm or less, preferably 30 nm or less. Here, the residual film 51 means the part where the resin is thinnest for each of the grating pattern of the incident part 2 formed by the incident part pattern 62 and the grating pattern of the exit part 3 formed by the exit part pattern 63.

[0058] Thereafter, the resin 5 is solidified and released from the mold as shown in FIG. 8(d), thereby completing the manufacture of the optical waveguide of the present invention.

[0059] Next, the optical waveguide of the present invention thus manufactured will be described. The optical waveguide of the present invention is made of a transparent substrate 4 and a resin 5 formed on the surface of the transparent substrate 4. The optical waveguide is mainly made up of an input section 2, an output section 3, and a transfer section 1.

[0060] The transfer section 1 is for transferring light and is made of a transparent substrate 4 and a resin 5 formed flat on the surface of the transparent substrate 4. The light incident from the input section 2 is transferred while being totally reflected by the transfer section 1, and is emitted from the output section 3.

[0061] The incident section 2 is made of resin 5 formed as a grating pattern on the surface of a transparent substrate 4, and is used to make light incident on the transfer section 1. The grating pattern may have any shape as long as it can make light incident on the transfer section 1. For example, it can diffract light so that it travels through the transfer section 1 by total reflection, and can be a line-and-space pattern in which inclined convex sections are periodically arranged.

[0062] The emission section 3 is made of resin 5 formed as a grating pattern on the surface of the transparent substrate 4, and is for emitting light from the transfer section 1. The grating pattern may have any shape as long as it can emit light from the transfer section 1, but for example, it can diffract light so that it is emitted to the outside from the transparent substrate 4, and can be a line-and-space pattern in which inclined convex portions are periodically arranged.

[0063] The transparent substrate 4 is a base portion for forming a pattern on the flat portion of the transfer portion 1 and the resin 5 of the incident portion 2 and the exit portion 3. It is also for transferring the light incident from the incident portion 2 to the exit portion 3. Any material may be used as long as it can transfer the light from the incident portion 2 to the exit portion 3, and for example, glass can be used. Furthermore, from the results of the above-mentioned simulation, the refractive index of the transparent substrate 4 is preferably 1.8 or more, more preferably 1.9 or more, and even more preferably 2.0 or more.

[0064] Resin 5 is for forming the patterns of incident section 2, exit section 3, and transfer section 1. Any material may be used as long as it can form the patterns of transfer section 1, incident section 2, and exit section 3. Furthermore, from the results of the above-mentioned simulation, the refractive index of transparent substrate 4 and resin 5 is preferably 1.8 or more, more preferably 1.9 or more, and even more preferably 1.95 or more.

[0065] In addition, the optical waveguide of the present invention is preferably formed so that, when the height of the convex portion of the grating pattern of the input portion 2 or the output portion 3 is b, the fill factor of the convex portion is ff, the thickness of the residual film 51 is d, and the thickness of the resin 5 of the transfer portion 1 adjacent to the grating pattern is t, it is at least 0.9×(d+b×ff)≦t≦1.1×(d+b×ff), preferably 0.95×(d+b×ff)≦t≦1.05×(d+b×ff), and more preferably 0.97×(d+b×ff)≦t≦1.03×(d+b×ff). Most preferably, when it is formed so that t=d+b×ff, the transfer portion 1 has a good shape with less waviness and voids 9. The fill factor of the convex portion means the ratio of the area of ​​the convex portion to the area of ​​the pattern surface. The fill factor ff of the convex portion of the grating pattern of the incident portion 2 or the exit portion 3 of the optical waveguide is basically the same as the fill factor (1-FF) of the concave portion of the incident portion pattern 62 or the exit portion pattern 63. The depth D of the transfer portion pattern 61 refers to the difference in height between the flat surface of the transfer portion pattern 61 and the height of the apex of the convex portion of the incident portion pattern 62 or the exit portion pattern 63, as shown in FIG.

[0066] Furthermore, the thickness d of the remaining film 51 of the grating pattern in the entrance portion 2 and the exit portion 3 is preferably 100 nm or less, more preferably 30 nm or less, because this improves the diffraction efficiency on the wide angle side.

[0067] In the above description, the optical waveguide mold 6 has been described in which the depths B of the incident portion pattern 62 and the exit portion pattern 63 are the same, and the difference D between the height of the incident portion pattern 62 or the exit portion pattern 63 and the height of the transfer portion pattern 61 is also the same, but these may be different. In this case, the optical waveguide mold 6 is formed of a transparent substrate 4 and a resin 5 formed on the surface of the transparent substrate 4, and is for manufacturing an optical waveguide comprising a transfer portion 1 for transferring light, an incident portion 2 for making light incident on the transfer portion 1, and an exit portion 3 for making light exit from the transfer portion 1, and comprises a flat transfer portion pattern for forming the transfer portion 1 in the resin 5, an incident portion pattern for forming the incident portion 2 in the resin 5, and an exit portion pattern for forming the exit portion 3 in the resin 5. In addition, in the optical waveguide mold 6, the depth of the concave portion of the pattern for the incident portion is B1, the fill factor of the convex portion is FF1, the depth of the concave portion of the pattern for the emission portion is B2, the fill factor of the convex portion is FF2, the difference in height between the pattern for the incident portion and the pattern for the transfer portion is D1, and the difference in height between the pattern for the emission portion and the pattern for the transfer portion is D2, and the following formula is satisfied: 0.9×B1×(1-FF1)≦D1≦1.1×B1×(1-FF1) 0.9×B2×(1-FF2)≦D2≦1.1×B2×(1-FF2) In this formula, an error of ±10% is allowed, but of course the smaller the error the better, preferably 5% or less, and more preferably 3% or less.

[0068] When the optical waveguide mold 6 is used for imprint molding, the manufactured optical waveguide is made of a transparent substrate 4 and a resin 5 formed on the surface of the transparent substrate 4, and has a transfer section 1 for transferring light, which is made of the transparent substrate 4 and the resin 5 formed flat on the surface of the transparent substrate 4, an entrance section 2 for making light incident on the transfer section 1, and an exit section 3 for making light exit from the transfer section 1, which is made of the resin 5 formed as a grating pattern on the surface of the transparent substrate 4. In addition, if the height of the convex portion of the grating pattern of the entrance section 2 is b1, the fill factor of the convex portion is ff1, the thickness of the residual film is d1, the height of the convex portion of the grating pattern of the exit section 3 is b2, the fill factor of the convex portion is ff2, and the thickness of the residual film is d2, the thickness t of the resin 5 of the transfer section 1 is calculated by the following formula: 0.9×(d1+b1×ff1)≦t≦1.1×(d1+b1×ff1) 0.9×(d2+b2×ff2)≦t≦1.1×(d2+b2×ff2) It will satisfy the following.

[0069] Figure 14 is a schematic cross-sectional view showing the manufacturing process of an optical waveguide when the positions of the tops of the pattern for the entrance portion 62 and the pattern for the exit portion 63 relative to the flat surface of the pattern for the transfer portion 61 of the mold for the optical waveguide 6 are aligned (D1 = D2), but the positions of the bottoms of the pattern for the entrance portion 62 and the pattern for the exit portion 63 of the mold for the optical waveguide 6 are different.

[0070] In this case, as shown in Figure 14(d), the manufactured optical waveguide has the same thickness of the residual film of the grating pattern in the incident section 2 and the exit section 3 (d1 = d2), but the height b1 of the convex portion of the grating pattern in the incident section 2 and the height b2 of the convex portion of the grating pattern in the exit section 3 are different.

[0071] Also, Figure 15 is a schematic cross-sectional view showing the manufacturing process of an optical waveguide when the positions of the bottoms of the pattern for the entrance portion 62 and the pattern for the exit portion 63 relative to the flat surface of the pattern for the transfer portion 61 of the mold for the optical waveguide 6 are aligned (B1-D1=B2-D2), but the positions of the tops of the pattern for the entrance portion 62 and the pattern for the exit portion 63 of the mold for the optical waveguide 6 are different.

[0072] In this case, as shown in Figure 15(d), the position of the apex of the grating pattern in the incident part 2 and the exit part 3 of the manufactured optical waveguide is the same (b1 + d1 = b2 + d2), but the thickness of the residual film of the grating pattern in the incident part 2 and the exit part 3 is different.

[0073] The optical waveguide mold 6 is D1 = B1 × (1-FF1) D2 = B2 × (1-FF2) When the above condition is satisfied, the resin 5 is most unlikely to move laterally, which is preferable.

[0074] In this case, the manufactured optical waveguide has a thickness t of the resin 5 of the transfer section 1 that satisfies the following formula: t=d1+b1×ff1=d2+b2×ff2=d3+b3×ff3 It will satisfy the following.

[0075] Furthermore, it is preferable that the thicknesses d1 and d2 of the grating patterns of the incident portion 2 and the exit portion 3 are 100 nm or less in order to improve the diffraction efficiency on the wide-angle side. Here, the residual film 51 means the portion where the resin is thinnest for each of the grating pattern of the incident portion 2 formed by the pattern for the incident portion 62 and the grating pattern of the exit portion 3 formed by the pattern for the exit portion 63. Either the thickness d1 or d2, or preferably both, should be 100 nm or less, and more preferably 30 nm or less.

[0076] The optical waveguide may also have an expansion section 7 for expanding the exit pupil, as shown in Fig. 16. In this case, the optical waveguide 8A is made of a transparent substrate 4 and a resin 5 formed on the surface of the transparent substrate 4, as shown in Fig. 17(d), and is mainly composed of a first transfer section 1A, a second transfer section 1B, an entrance section 2, an expansion section 7, and an exit section 3.

[0077] The first transfer section 1A and the second transfer section 1B are made of a transparent substrate 4 and a resin 5 formed flat on the surface of the transparent substrate 4, and are intended to transfer light. Light incident from the entrance section 2 is transferred to the magnification section 7 while being totally reflected by the first transfer section 1A. Light incident from the magnification section 7 is transferred while being totally reflected by the second transfer section 1B, and is emitted from the exit section 3.

[0078] The incident section 2 is made of resin 5 formed as a grating pattern on the surface of a transparent substrate 4, and serves to make light incident on the first transfer section 1A. The grating pattern may have any shape as long as it can make light incident on the first transfer section 1A. For example, it can diffract light so that it travels through the first transfer section 1A by total reflection, and can be a line-and-space pattern in which inclined convex sections are periodically arranged.

[0079] The emission section 3 is made of resin 5 formed as a grating pattern on the surface of the transparent substrate 4, and is for emitting light from the second transfer section 1B. The grating pattern may have any shape as long as it can emit light from the second transfer section 1B, but for example, it can diffract light so that it is emitted to the outside from the transparent substrate 4, and can be a line-and-space pattern in which inclined convex portions are periodically arranged.

[0080] The enlargement section 7 is disposed between the first transfer section 1A and the second transfer section 1B, and is made of a resin 5 formed as an enlargement pattern on the surface of the transparent substrate 4, and is for controlling the light incident from the first transfer section 1A and outputting it to the second transfer section 1B in order to enlarge the exit pupil. The enlargement pattern may have any shape as long as it can control the light incident from the first transfer section 1A and output it to the second transfer section 1B in order to enlarge the exit pupil. For example, it can be a line-and-space grating pattern in which convex portions are periodically arranged, which can duplicate the light incident from the first transfer section 1A and enlarge the exit pupil. In this case, the pitch of the convex portions of the enlargement pattern may be 1 / √2 times that of the grating patterns of the entrance section 2 and the exit section 3.

[0081] The transparent substrate 4 is a base portion for forming a pattern on the flat portion of the first transfer section 1A and the second transfer section 1B, and on the resin 5 of the incident section 2 and the exit section 3. It is also for transferring the light incident from the incident section 2 to the exit section 3. Any material may be used as long as it can transfer the light from the incident section 2 to the exit section 3, and for example, glass can be used. Furthermore, from the results of the above-mentioned simulation, the refractive index of the transparent substrate 4 is preferably 1.8 or more, more preferably 1.9 or more, and even more preferably 2.0 or more.

[0082] The resin 5 is for forming the patterns of the incident section 2, the exit section 3, the magnification section 7, the first transfer section 1A, and the second transfer section 1B. Any material may be used as long as it can form the patterns of the transfer section 1, the incident section 2, and the exit section 3. Furthermore, from the results of the above-mentioned simulation, the refractive index of the transparent substrate 4 and the resin 5 is preferably 1.8 or more, more preferably 1.9 or more, and even more preferably 1.95 or more.

[0083] 17(a), the optical waveguide mold 6A for manufacturing an optical waveguide having this enlarged portion 7 is mainly composed of a first transfer portion pattern 61A, a second transfer portion pattern 61B, an entrance portion pattern 62A, an exit portion pattern 63A, and an enlarged portion pattern 67. The material for the optical waveguide mold 6A may be any material that can be used for imprinting, and well-known materials such as glass can be used.

[0084] The first transfer part pattern 61A is a flat pattern for forming a flat portion of the first transfer part 1A in the resin 5. The second transfer part pattern 61B is a flat pattern for forming a flat portion of the second transfer part 1B in the resin 5.

[0085] The pattern for incident portion 62A is for forming the incident portion 2 in the resin 5. The pattern for incident portion 62 may be of any type as long as it can form the incident portion 2 in the resin 5, but for example, it may be a pattern that is an inversion of the grating pattern of the incident portion 2 described above.

[0086] The pattern 63A for the emission portion is for forming the emission portion 3 in the resin 5. The pattern 63 for the emission portion may be any pattern as long as it can form the emission portion 3 in the resin 5, but for example, it may be a pattern obtained by inverting the grating pattern of the emission portion 3 described above.

[0087] The pattern 67 for the enlarged portion is for forming the enlarged portion 7 in the resin 5. The pattern 67 for the enlarged portion may be any pattern as long as it can form the enlarged portion 7 in the resin 5, but for example, it may be a pattern that is an inversion of the pattern for enlarging the enlarged portion 3 described above.

[0088] Here, in order to prevent lateral movement of the resin 5 when pressurizing the resin 5 with the optical waveguide mold 6A, it is only necessary to balance the volume per unit space of the gaps (recesses) in the incident portion pattern 62A and the enlarged portion pattern 67 and the gaps in the first transfer portion pattern 61A adjacent to the incident portion pattern 62A and the enlarged portion pattern 67, and the gaps in the exit portion pattern 63A and the second transfer portion pattern 61B adjacent to the enlarged portion pattern 67. Specifically, assuming that the depth of the recesses of the pattern 62A for the incident portion is B1, the fill factor of the protrusions is FF1, the depth of the recesses of the pattern 63A for the emission portion is B2, the fill factor of the protrusions is FF2, the depth of the recesses of the pattern 67 for the enlarged portion is B3, and the fill factor of the protrusions is FF3, then the difference D1 between the height of the pattern 62A for the incident portion and the height of the pattern 61A for the first transfer portion, the difference D2 between the height of the pattern 63A for the emission portion and the height of the pattern 61B for the second transfer portion, and the difference D3 between the height of the pattern 67 for the enlarged portion and the pattern 61A for the first transfer portion or the pattern 61B for the second transfer portion are expressed by the following formulas: 0.9×B1×(1-FF1)≦D1≦1.1×B1×(1-FF1) 0.9×B2×(1-FF2)≦D2≦1.1×B2×(1-FF2) 0.9×B3×(1-FF3)≦D3≦1.1×B3×(1-FF3) In this formula, an error of ±10% is allowed, but of course the smaller the error the better, preferably 5% or less, and more preferably 3% or less.

[0089] In this case, in the optical waveguide 8A manufactured by the optical waveguide mold 6A, the height of the convex portion of the grating pattern of the entrance portion 2 is b1, the fill factor of the convex portion is ff1, the thickness of the residual film is d1, the height of the convex portion of the grating pattern of the exit portion is b2, the fill factor of the convex portion is ff2, the thickness of the residual film is d2, the height of the convex portion of the grating pattern of the expansion portion 7 is b3, the fill factor of the convex portion is ff3, and the thickness of the residual film is d3, the thickness t of the resin of the first transfer portion 1A and the second transfer portion 1B is expressed by the following formula: 0.9×(d1+b1×ff1)≦t≦1.1×(d1+b1×ff1) 0.9×(d2+b2×ff2)≦t≦1.1×(d2+b2×ff2) 0.9×(d3+b3×ff3)≦t≦1.1×(d3+b3×ff3) Meet the following.

[0090] 17(a), the optical waveguide mold 6A has the top positions of the incident portion pattern 62A, the emission portion pattern 63A, and the enlarged portion pattern 67 aligned with respect to the flat surfaces of the first transfer portion pattern 61A and the second transfer portion pattern 61B (D1=D2=D3), but the bottom positions of the incident portion pattern 62A, the emission portion pattern 63A, and the enlarged portion pattern 67 of the optical waveguide mold 6A can be different. Fig. 17 is a schematic cross-sectional view showing a manufacturing process of an optical waveguide when imprint molding is performed using the optical waveguide mold 6A.

[0091] In this case, as shown in Figure 17(d), the manufactured optical waveguide 8A has the same thickness of the residual film in the patterns of the incident section 2, the exit section 3, and the expansion section 7 (d1 = d2 = d3), but the height b1 of the convex portions of the grating pattern of the incident section 2, the height b2 of the convex portions of the grating pattern of the exit section 3, and the height b3 of the convex portions of the pattern of the expansion section 7 are different.

[0092] 18(a), the optical waveguide mold 6A has the bottom positions of the incident portion pattern 62A, the exit portion pattern 63A, and the enlarged portion pattern 67 aligned with respect to the flat surfaces of the first transfer portion pattern 61A and the second transfer portion pattern 61B (B1-D1=B2-D2=B3-D3), but the top positions of the incident portion pattern 62A, the exit portion pattern 63A, and the enlarged portion pattern 67 of the optical waveguide mold 6A may be different. Fig. 18 is a schematic cross-sectional view showing the manufacturing process of an optical waveguide when imprint molding is performed using the optical waveguide mold 6A.

[0093] In this case, as shown in Figure 18 (d), the manufactured optical waveguide 8A has the same positions of the apexes of the patterns of the incident section 2, the exit section 3, and the expansion section 7 (b1 + d1 = b2 + d2 = b3 + d3), but the thicknesses of the residual films of the patterns of the incident section 2, the exit section 3, and the expansion section 7 are different.

[0094] In addition, the optical waveguide mold 6A is D1 = B1 × (1-FF1) D2 = B2 × (1-FF2) D3 = B3 × (1-FF3) When the above condition is satisfied, the resin 5 is most unlikely to move laterally, which is preferable.

[0095] In this case, the manufactured optical waveguide has a thickness t of the resin 5 of the first transfer section 1A and the second transfer section 1B, which is expressed by the following formula: t=d1+b1×ff1=d2+b2×ff2=d3+b3×ff3 It will satisfy the following.

[0096] In addition, the thicknesses d1, d2, and d3 of the residual film 51 of the grating patterns of the entrance portion 2 and the exit portion 3 and the enlargement pattern of the enlargement portion 7 are preferably 100 nm or less because the diffraction efficiency on the wide-angle side is improved. Here, the residual film 51 means the portion where the resin is thinnest for each of the grating pattern of the entrance portion 2 formed by the pattern for the entrance portion 62A, the grating pattern of the exit portion 3 formed by the pattern for the exit portion 63A, and the enlargement pattern of the enlargement portion 7 formed by the pattern for the enlargement portion 67. Any one or more of the thicknesses d1, d2, and d3, preferably all of them, should be 100 nm or less, and more preferably 30 nm or less. [Explanation of symbols]

[0097] 1. Transfer section 1A First Transfer Section 1B Second Transfer Section 2 Input part 2A entrance section 3. Output section 3A output part 4 Transparent substrate 5. Resin 6. Optical Waveguide Mold 6A Optical Waveguide Mold 7 Enlarged section 8 Optical waveguide 8A optical waveguide 9 void 51 Remaining membrane 61 Transfer section pattern 61A First transfer section pattern 61B Pattern for second transfer section 62 Incident pattern 62A Incident pattern 63 Pattern for emission part 63A Emission pattern 67 Enlarged section pattern

Claims

1. A mold for an optical waveguide for manufacturing an optical waveguide, the mold being formed of a transparent substrate and a resin formed on a surface of the transparent substrate, the mold comprising a transfer section for transferring light, an incident section for making light incident on the transfer section, and an exit section for making the light exit from the transfer section, a flat transfer portion pattern for forming the transfer portion in the resin; At least one or both of an incident portion pattern for forming the incident portion in the resin and an emission portion pattern for forming the emission portion in the resin; When the depth of the concave portion of the pattern for the incident portion or the pattern for the emission portion is B, the fill factor of the convex portion is FF, and the difference between the height of the pattern for the incident portion or the pattern for the emission portion and the height of the pattern for the transfer portion is D, the following formula is obtained: 0.9×B×(1-FF)≦D≦1.1×B×(1-FF) 1. A mold for an optical waveguide, comprising:

2. D = B x (1 - FF) 2. The optical waveguide mold according to claim 1, wherein the above-mentioned satisfies the above.

3. A mold for an optical waveguide for manufacturing an optical waveguide, the mold being formed of a transparent substrate and a resin formed on a surface of the transparent substrate, the mold comprising a transfer section for transferring light, an incident section for making light incident on the transfer section, and an exit section for making the light exit from the transfer section, a flat transfer portion pattern for forming the transfer portion in the resin; an incidence portion pattern for forming the incidence portion in the resin; an emission portion pattern for forming the emission portion in the resin; The depth of the recess of the pattern for the incident portion is B １ , the fill factor of the convex part is FF １ The depth of the recess of the pattern for the emission part is B ２ , the fill factor of the convex part is FF ２ The difference between the height of the pattern for the incident portion and the height of the pattern for the transfer portion is D １ The difference between the height of the pattern for the emission part and the height of the pattern for the transfer part is D ２ Then, the following formula 0.9×B １ ×(1-FF １ )≦D １ ≦1.1×B １ ×(1-FF １ ) 0.9×B ２ ×(1-FF ２ )≦D ２ ≦1.1×B ２ ×(1-FF ２ ) 1. A mold for an optical waveguide, comprising:

4. D １ =D ２ 4. The optical waveguide mold according to claim 3, wherein the above-mentioned satisfies the above.

5. B １ -D １ =B ２ -D ２ 4. The optical waveguide mold according to claim 3, wherein the above-mentioned satisfies the above.

6. D １ =B １ ×(1-FF １ ) D ２ =B ２ ×(1-FF ２ ) 4. The optical waveguide mold according to claim 3, wherein the above-mentioned satisfies the above.

7. A mold for an optical waveguide for manufacturing an optical waveguide, the mold being formed of a transparent substrate and a resin formed on a surface of the transparent substrate, the mold comprising: a first transfer section and a second transfer section for transferring light; an entrance section for making light incident on the first transfer section; an expansion section disposed between the first transfer section and the second transfer section for expanding an exit pupil, the expansion section controlling the light incident from the first transfer section and outputting it to the second transfer section; and an exit section for outputting the light from the second transfer section, a flat first transfer portion pattern for forming the first transfer portion in the resin; a flat second transfer portion pattern for forming the second transfer portion in the resin; an incidence portion pattern for forming the incidence portion in the resin; an emission portion pattern for forming the emission portion in the resin; an enlarged portion pattern for forming the enlarged portion in the resin; The depth of the recess of the pattern for the incident portion is B １ , the fill factor of the convex part is FF １ , the depth of the recess of the pattern for the emission part is B ２ , the fill factor of the convex part is FF ２ , the depth of the recess of the enlarged portion pattern is B ３ , the fill factor of the convex part is FF ３ , the difference D between the height of the pattern for the incident portion and the height of the pattern for the first transfer portion １ , the difference D between the height of the pattern for the emission part and the height of the pattern for the second transfer part ２ , the difference D between the height of the pattern for the enlarged portion and the height of the pattern for the first transfer portion or the pattern for the second transfer portion ３ is expressed by the following formula: 0.9×B １ ×(1-FF １ )≦D １ ≦1.1×B １ ×(1-FF １ ) 0.9×B ２ ×(1-FF ２ )≦D ２ ≦1.1×B ２ ×(1-FF ２ ) 0.9×B ３ ×(1-FF ３ )≦D ３ ≦1.1×B ３ ×(1-FF ３ ) 1. A mold for an optical waveguide, comprising:

8. D １ =D ２ =D ３ 8. The optical waveguide mold according to claim 7, wherein the above-mentioned satisfies the above.

9. B １ -D １ =B ２ -D ２ =B ３ -D ３ 8. The optical waveguide mold according to claim 7, wherein the above-mentioned satisfies the above.

10. D １ =B １ ×(1-FF １ ) D ２ =B ２ ×(1-FF ２ ) D ３ =B ３ ×(1-FF ３ ) 8. The optical waveguide mold according to claim 7, wherein the above-mentioned satisfies the above.

11. A method for producing an optical waveguide, comprising performing imprint molding using the optical waveguide mold according to claim 1 .

12. 12. The method for manufacturing an optical waveguide according to claim 11, wherein the refractive index of the resin is 1.8 or more.

13. 12. The method for manufacturing an optical waveguide according to claim 11, wherein the imprint molding is performed so that a thickness of a residual resin film formed by at least one of the incident portion pattern and the emission portion pattern is 100 nm or less.

14. An optical waveguide including a transparent substrate and a resin formed on a surface of the transparent substrate, a transfer section for transferring light, the transfer section being made of the transparent substrate and a resin formed flat on a surface of the transparent substrate; an incidence section for allowing light to be incident on the transfer section, the incidence section being made of a resin formed as a grating pattern on a surface of the transparent substrate; an emission section for emitting the light from the transfer section, the emission section being made of a resin formed as a grating pattern on a surface of the transparent substrate; The height of the convex portion of the grating pattern of the incident portion is b １ , the fill factor of the convex part is ff １ , the thickness of the remaining film is d １ The height of the convex portion of the grating pattern of the emission portion is b ２ , the fill factor of the convex part is ff ２ , the thickness of the remaining film is d ２ Then, the thickness t of the resin in the transfer portion is expressed by the following formula: 0.9×(d １ +b １ ×ff １ )≦t≦1.1×(d １ +b １ ×ff １ ) 0.9×(d ２ +b ２ ×ff ２ )≦t≦1.1×(d ２ +b ２ ×ff ２ ) An optical waveguide characterized by satisfying the above.

15. d １ =d ２ 15. The optical waveguide according to claim 14, wherein the following is satisfied:

16. b １ +d １ =b ２ +d ２ 15. The optical waveguide according to claim 14, wherein the following is satisfied:

17. t=d １ +b １ ×ff １ =d ２ +b ２ ×ff ２ 15. The optical waveguide according to claim 14, wherein the following is satisfied:

18. An optical waveguide including a transparent substrate and a resin formed on a surface of the transparent substrate, a first transfer section and a second transfer section for transferring light, the first transfer section and the second transfer section being made of the transparent substrate and a resin formed flat on a surface of the transparent substrate; an incidence section for allowing light to be incident on the first transfer section, the incidence section being made of a resin formed as a grating pattern on a surface of the transparent substrate; an enlargement section that is disposed between the first transfer section and the second transfer section, is made of a resin formed as an enlargement pattern on the surface of the transparent substrate, and controls light incident from the first transfer section to enlarge an exit pupil and outputs the light to the second transfer section; an emission section that is made of a resin formed as a grating pattern on a surface of the transparent substrate and that emits the light from the second transfer section; The height of the convex portion of the grating pattern of the incident portion is b １ , the fill factor of the convex part is ff １ , the thickness of the remaining film is d １ The height of the convex portion of the grating pattern of the emission portion is b ２ , the fill factor of the convex part is ff ２ , the thickness of the remaining film is d ２ The height of the convex portion of the enlargement pattern of the enlargement portion is b ３ , the fill factor of the convex part is ff ３ , the thickness of the remaining film is d ３ Then, the thickness t of the resin in the first transfer section and the second transfer section is expressed by the following formula: 0.9×(d １ +b １ ×ff １ )≦t≦1.1×(d １ +b １ ×ff １ ) 0.9×(d ２ +b ２ ×ff ２ )≦t≦1.1×(d ２ +b ２ ×ff ２ ) 0.9×(d ３ +b ３ ×ff ３ )≦t≦1.1×(d ３ +b ３ ×ff ３ ) An optical waveguide characterized by satisfying the above.

19. d １ =d ２ =d ３ 20. The optical waveguide according to claim 18, wherein the following is satisfied:

20. b １ +d １ =b ２ +d ２ =b ３ +d ３ 20. The optical waveguide according to claim 18, wherein the following is satisfied:

21. t=d １ +b １ ×ff １ =d ２ +b ２ ×ff ２ =d ３ +b ３ ×ff ３ 20. The optical waveguide according to claim 18, wherein the following is satisfied:

22. 22. The optical waveguide according to claim 14, wherein the resin has a refractive index of 1.8 or more.

23. 22. The optical waveguide according to claim 14, wherein a thickness of a residual film of at least one of the grating patterns at the entrance portion and the exit portion is 100 nm or less.

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