JP4840668B2 - Thermal imprint mold and method for producing optical element using the mold - Google Patents

Description

  The present invention relates to a thermal imprint mold that does not cause chipping or deformation of a pattern formed by air taken into an imprint pattern during thermal imprinting, and a method of manufacturing an optical element using the thermal imprint mold. .

  In recent years, with the development of science and technology, fine optical elements are required in various fields. In particular, the transmission of information is changing from radio waves to light in the communications field, and wavelength demultiplexing optical elements are used to separate the wavelengths of multiplexed and transmitted light. Accuracy is required.

  Conventionally, such an optical element has been manufactured by depositing an inorganic substance on a glass substrate, or by exposing a transparent member such as a stone wall or glass to an electronic boom exposure and etching process. The cost is very high because it is complicated and difficult to mass-produce.

  Therefore, in recent years, a method of manufacturing an optical element by thermal imprinting has been proposed as a simpler manufacturing method. In thermal imprinting, it is possible to create an optical element by creating a mold for creating an optical element and pressing the mold against a transfer resin that forms the optical element. Mass production is possible.

  However, as a fine pattern is required by the optical element to be created, the required pitch width of the mold pattern becomes nano-order, and there is no deformation or chipping of the pattern due to air remaining in the pattern when the mold is pressed. This is a major problem in the field of optical communications where high transfer accuracy is required.

  In order to prevent the deformation and chipping of the pattern due to such residual air, it is known to perform mold pressing under vacuum, but the cost is high because large equipment and devices are required to create a vacuum. There was a problem of becoming.

  As another method, claim 1 of Patent Document 1 (Japanese Patent Laid-Open No. 2007-42715) states that “an imprint in which a concavo-convex pattern formed on an imprint mold is transferred to a resist layer of a resist layer forming substrate. An imprint mold for use in the method, wherein a microtrench (a minute recess) is formed in a recess of the uneven pattern of the imprint mold. " It is disclosed. By forming micro-trench (micro-recess) in the recess of the thermal imprint mold, the remaining air enters the micro-trench, so that deformation and chipping of the pattern are suppressed and transfer accuracy is improved. There is a problem that it is necessary to further form a microtrench (small concave portion) in the back of the thermal imprint mold, and it is very difficult to form a mold having such a microtrench.

Patent Document 2 (Japanese Patent Laid-Open No. 2006-289684) and Patent Document 3 (Japanese Patent Laid-Open No. 2007-190734) describe that a mold is placed on a pedestal and imprinted. When a mold is placed on such a pedestal, a gap may be formed between the pedestal and the mold. In these patent documents, such a gap is used to vent the air to obtain a highly accurate wavelength demultiplexing. The problem of forming a spectroscopic element is not shown. Therefore, in Patent Document 2 and Patent Document 3, there is no specific disclosure as to what configuration should be adopted in order to eliminate the influence of air when the wavelength demultiplexing spectroscopic element is manufactured by the thermal imprint method. .
JP 2007-42715 JP 2006-289684 A JP 2007-190734 A

  The present invention is a mold for producing an optical element having very fine irregularities on the surface, such as a wavelength demultiplexing optical element, by a thermal imprint method, and includes a mold and a substrate onto which a pattern is transferred. It is an object of the present invention to provide a thermal imprint mold in which the air between the two is efficiently exhausted at the time of contact and the transfer air is less likely to be deformed or chipped by residual air.

  Another object of the present invention is to provide a method for producing an optical element having a fine pattern, for example, a wavelength demultiplexing optical element, using the thermal imprint mold as described above.

  The mold for thermal imprinting according to the present invention has a transfer part having nano-order irregularities at a substantially central part of a mold substrate, and the substrate as a transfer member and the mold contact around the transfer part. In addition, in order to discharge air between the substrate and the mold, it is characterized by having a cutout portion formed 50 μm to 1 mm lower than the bottom portion of the recess formed in the mold.

Furthermore, in the method of manufacturing an optical element such as a wavelength demultiplexing optical element of the present invention, a mold having a large number of nano-order projections is brought into contact with the surface of the substrate, and the mold is pressurized under heating to be applied to the mold. A method of manufacturing an optical element that transfers the formed irregularities to a substrate surface,
When a transfer part provided with projections and depressions corresponding to projections made of nano-order projections formed on the substrate surface is provided in the substantially central part of the mold substrate, when the substrate and the mold contact around the transfer part In order to discharge the air between the substrate and the mold, a hot imprint mold having a notch formed 50 μm to 1 mm lower than the bottom of the recessed portion formed with the mold is heated with the substrate. It is characterized in that the unevenness formed on the mold is transferred to the substrate surface by contact.

  In the mold for thermal imprinting according to the present invention, the outermost convex portion or concave portion of the pattern region in which a large number of concave and convex portions formed in the mold form a blank region, and the convex portion forming the blank region is formed. It is preferable that the total area of the area of the blank area of the part or the area of the blank area of the recess and the area of the pattern area is within a range of 1.1 to 30 times the area of the pattern area.

  In the mold for thermal imprinting of the present invention, a notch for venting air is formed in the mold itself in order to efficiently extract air between the substrate and the mold. Furthermore, the outermost convex part or concave part of the pattern area formed with a large number of irregularities formed in this mold forms a blank area, so that the air can be exhausted more efficiently and formed by residual air. It is difficult for deformation or distortion of the projection to occur. In particular, when the outermost convex portion or concave portion of the pattern region forms a blank region, the projection can be transferred with higher accuracy.

  Therefore, since the shape of the formed protrusion completely matches the shape of the unevenness formed on the mold, the wavelength demultiplexing optical element obtained by the manufacturing method of the present invention is designed to demultiplex light having a wavelength to be demultiplexed. There is no deviation from the light of the specified wavelength.

  By using the imprint mold of the present invention, the air existing between the mold and the substrate can be easily exhausted from the notch, and the shape of the formed protrusion is completely the same as the shape of the mold. In addition, there is no deviation in the formation cycle of the protrusions. In particular, the shape of the protrusions is not deformed by such residual air, and the formation cycle of the protrusions is not shifted.

Next, a method for manufacturing a thermal imprint mold of the present invention and an optical element manufactured using the thermal imprint mold, for example, a wavelength demultiplexing spectroscopic element will be described in detail.
As shown in FIGS. 1 and 2, the thermal imprint mold 10 of the present invention includes a mold base 12, and convex portions 14 and concave portions 16 formed on the surface of the imprint mold 10. .

In the conventional mold, as shown in FIG. 11, a convex portion 14 is formed on the surface of the mold base 12, and a concave portion 16 is formed between the convex portion 14 and the adjacent convex portion 14.
Therefore, when the substrate is pressed against the mold base 12 and the unevenness formed on the mold 12 is transferred to the substrate, the air near the center of the mold 12 is difficult to escape, and residual air marks may remain on the transferred unevenness. There are deformations and distortions of the formed protrusions.

  In the mold for thermal imprinting of the present invention, for example, the mold base of the mold base 12 as shown in FIG. 11 where the unevenness for transfer is not formed is removed, and residual air is removed from this part. I try to come out. In FIG. 1 and FIG. 2, a gap portion indicated by a two-dot chain line 21 is a notch portion 20. The depth S of the notch 20 is 50 μm to 1 mm, preferably 200 μm to 750 μm. Incidentally, the height H of the concavo-convex portion formed on the mold base 12 is usually 200 to 600 nm, preferably 300 to 450 nm.

  By forming the notch 20 at such a depth, exhaust can be performed very efficiently during transfer. If this notch is less than 50 μm, the formed pattern is chipped or distorted. If it exceeds 1 mm (1000 μm), it is difficult to form the mold itself.

  Furthermore, in the mold for thermal imprinting of the present invention, blank regions 23 and 25 are formed in the outermost convex portion 25 of the pattern region in which many irregularities formed in the mold are formed or the outermost concave portion 23 of the pattern region. It is preferable. In FIG. 3, the blank area is indicated by hatching, and a number 23 is assigned to the blank area. For example, the area of the blank region of the convex portion 25 as shown in FIG. 3 or the total area of the blank region and the pattern region of the concave portion 23 is usually 1. It exists in the range of 1-30 times, Preferably it exists in the range of 1.5-30 times, More preferably, it exists in the range of 2-20 times.

  By forming the blank regions 23 and 25 in such an area ratio, the remaining air can be removed more efficiently. The area ratio of the total area of the area of the blank area and the area of the pattern area (the area where the transfer portion is formed) to the pattern area greatly affects the shape of the formed protrusion. If the ratio is less than 1.times., The effective area of the pattern region to be formed becomes small, and if it exceeds 35 times, the formed pattern tends to be distorted. The upper limit of this ratio is usually 30. Times, preferably 20 times.

  In the blank area 23, a blank area having the same height level as the bottom height level of the concave portion of the transfer portion shown in FIG. 1, and a height level of the top portion of the convex portion of the transfer portion as shown in FIG. Although there is a blank area 25 having a height level, in the present invention, it is possible to exhaust the residual air satisfactorily in any type of blank area.

  In a wavelength demultiplexing optical element, in order to demultiplex light of a specific wavelength from a bundle of incident light, the refractive index of the substrate has a great influence, and light that is demultiplexed by the pitch width of the protrusions formed by the mold Therefore, if the pitch width of the protrusions formed on the substrate is slightly deviated due to a small amount of air remaining, the wavelength of the demultiplexed light is deviated. By manufacturing a wavelength demultiplexing optical element using a mold in which a notch and a blank region are appropriately formed as described above, the demultiplexing accuracy of such a wavelength demultiplexing optical element is greatly improved.

  The thickness of the mold base 12 in which the notches 20 and the blank regions 23 and 25 are appropriately formed as described above is the press base to which the mold base 12 is attached as shown in FIGS. 50 can be set as appropriate.

  Further, as shown in FIG. 4, the convex portion 14 and the concave portion 16 formed by the mold base 12 are formed with a prismatic convex portion 14 so as to form a prismatic projection (convex portion) 14. Alternatively, it may be a ridge having a rectangular cross section as shown in FIG.

  Such a mold is formed of a hard member such as metal, quartz or glass. A mold made of a mold base made of such a material can be manufactured by cutting the mold base using, for example, a diamond cutter or a laser beam.

Next, a method for manufacturing an optical element using the thermal imprint mold according to the present invention will be specifically described by taking a wavelength demultiplexing optical element as an example.
The imprint mold of the present invention is used by being fixed to a press base 50 as shown in FIGS. The press base 50 is fixed to a drive shaft 60 that can move up and down.

A base material fixing base 40 is provided below the press base 50, and the substrate 30 is placed on the base material fixing base 40.
Examples of the substrate used here include thermoplastic resins such as acrylic resin and polycarbonate resin, and glass.

  In manufacturing the wavelength demultiplexing optical element of the present invention, the mold and the substrate are brought into contact so that no air remains between the mold and the substrate, and the air between the mold and the substrate is heated when heated. It is preferable to reduce as much as possible. The contact between the two can be performed at normal pressure, but may be performed under reduced pressure.

  At this time, the substrate is usually set to a temperature equal to or higher than the glass transition temperature (Tg) of the resin used, preferably 70 to 180 ° C., particularly preferably 100 to 140 ° C., or higher than the melting point of the glass. , Under pressure so that the mold can penetrate into the substrate.

  In the wavelength demultiplexing optical element manufactured in this way, air between the mold and the substrate can be easily released by forming a notch for air venting in the mold, and in the presence of 0.06 hPa to 1013 hPa air, Even if the mold and the substrate are brought into contact with each other, air does not remain and the pattern is not deformed by the remaining air, so that the protrusions stand up at right angles and the pitch of the protrusions to be formed is not disturbed.

  When the width of the convex portion 14 formed on the mold substrate 12 shown in FIGS. 4 and 5 is L, the distance between the convex portions adjacent to both sides is as follows. Usually, it is preferably within 2 L with respect to L.

  Further, as the substrate 30 for forming the wavelength demultiplexing optical element, it is possible to use a laminate of a plurality of transparent synthetic resins having different refractive indexes. In FIGS. 6 and 7, three types having different refractive indexes are used. An embodiment using a laminate in which a transparent resin is laminated is shown.

  In the production of the wavelength demultiplexing optical element in the present invention, a single-layer substrate can be used, but the substrate used is a three-layer structure of at least a transparent substrate 37, a transparent resin intermediate layer 35, and a transparent resin top layer 31. It is preferable to have.

  The difference (n2−n1) between the refractive index (n2) of the top layer of the wavelength demultiplexing optical element having the three-layer structure and the refractive index (n1) of the transparent resin intermediate layer is preferably 0.06 to 0.25. It is preferable to select the resin so that it falls within the range of 0.1 to 0.2.

  Furthermore, the difference (n0−n1) between the refractive index (n0) of the transparent substrate layer of the transparent resin having the three-layer structure and the refractive index (n1) of the transparent resin intermediate layer is usually −0.1 to 0.3. Preferably, the resin is selected so that it falls within the range of 0 to 0,15.

  Furthermore, the width W when formed in the mold is usually in the range of 650 to 680 nm, preferably 665 to 675 nm, and the width G of the recess between the adjacent protrusions is usually 350 to 380 nm. Preferably it exists in the range of 355-365 nm.

  The concave / convex pattern of the mold for manufacturing such a wavelength demultiplexing optical element has an occupied volume of the convex portion with respect to the total volume of the convex portion and the concave portion (respectively, the concave portion and the convex portion of the mold) It is preferable to form the concavo-convex pattern so that (fill factor; FF) is in the range of 0.07 to 0.95.

  In the production of such a wavelength demultiplexing optical element, by using the mold in which the notch for air venting of the present invention is used, air between the mold and the resin substrate forming the optical element is easily released, Even if thermal imprinting is performed in an environment where air such as 6 Pa to 101.3 kPa exists, the air is discharged. Accordingly, deformation or chipping due to residual air does not occur on the convex surface of the formed wavelength demultiplexing optical element, so that the refractive index does not change due to the surface of the convex portion, and the wavelength of the demultiplexed light does not shift. .

  Thus, in the method for producing an optical element using the mold of the present invention, the optical element having a fine pattern is not required to have a large facility such as a vacuum apparatus, and a simple method called a thermal imprint method is used. It can be manufactured in large quantities with high transfer accuracy.

[Example 1]
Form a 3 mm square pattern area on a 4 inch square metal silicon with a thickness of 1 mm, cut the metal silicon with a diamond cutter, leaving a margin of 10 mm around the pattern area, and 11.2 mm square A small mold (mold base) was created.

A protrusion having a pitch width (P) of 1030 nm, a protrusion width (W) of 360 nm, a gap width (G) of 670 nm, and a height of 310 nm was formed on the surface of the center of the small mold.
The small mold around which the protrusions were formed as described above was cut to a depth of 500 μm with a diamond cutter to provide a notch for venting air around the blank area. The total of the area of the blank region thus formed and the area of the concavo-convex formation region was 15 times the area of the portion where the concavo-convex was formed.

  Separately, a transparent resin intermediate layer 35 made of polymethyl methacrylate having a film thickness of 3 μm is formed on the surface of a transparent substrate layer 37 made of a PET film having a base film of 100 μm, and the transparent resin intermediate layer 35 is made of polystyrene. A transparent resin substrate 30 having a three-layer structure in which a transparent resin top layer 31 having a thickness of 0.85 μm was laminated was manufactured.

The transparent resin substrate 30 was placed on the base material fixing base 40 and fixed.
In the apparatus on which the substrate fixing part is placed, a press base 50 for mounting the mold base 12 is installed, and the mold base 12 manufactured as described above is attached to the press base 50. It was.

  With the atmospheric pressure in the apparatus maintained at 1013 hPa, the transparent resin substrate placed and fixed on the base material fixing base 40 is heated to 140 ° C., and the mold base fixed to the press base is used as the transparent resin substrate. When the unevenness formed on the surface of the mold base by abutting for 300 seconds at a pressure of 1 MPa is transferred to the surface of the transparent resin top layer 31 of the transparent resin substrate, the temperature of the transparent resin substrate is lowered to 110 ° C. The material fixing base 40 was released from the transparent resin substrate.

  The surface of the obtained wavelength demultiplexing optical element was observed using an electron microscope. As a result, it was confirmed that lattice-shaped protrusions having a pitch width (P) of 1030 mm, a protrusion width (w) of 360 mm, and a height of 310 nm were formed on the surface of the transparent resin top layer 31. The protrusions were erected vertically from the surface of the transparent resin top layer 31, and no deflation due to residual air was observed at the boundary line between the transparent resin top layer and the protrusions.

In addition, the defect of the formed protrusion was visually observed and evaluated by observing a member that was thermally printed using the obtained mold with an optical microscope.
[Example 2]
In Example 1, the imprint mold was formed in the same manner except that the convex portions formed on the mold base were convex as shown in FIG. The pitch (P) of the ridges is 1030 nm, and the height (H) is 310 nm.

FIG. 9A shows an electron micrograph of a wavelength demultiplexing spectroscopic element formed using the mold base as described above.
In the above mold, a 100 μm blank area is formed on the outer side from the part where the unevenness is formed, and the total area of this blank area and the area where the unevenness is formed is such that the unevenness is formed. It is 15 times the part where it is.

  In this way, no traces due to residual air were found on the outside of the portion where the ridges were formed, but such a notch was not formed, for example, using the same mold base as shown in FIG. As shown in FIG. 8 (b), residual air marks were observed around the ridges of the wavelength demultiplexing spectrometer manufactured under the conditions.

Further, as shown in FIG. 9, it was found that there is a non-transfer portion due to residual air at the end portion of the ridge formed further enlarged.
Further, when the formed ridge portion is further enlarged and observed, as shown in FIG. 10 (a), the wavelength demultiplexing spectroscopic element manufactured using the base having the blank area formed on the mold base is shown. It can be seen that the ridges are formed vertically from the resin forming the transparent resin top layer. On the other hand, as shown in FIG. 10B, in the wavelength demultiplexing spectroscopic element manufactured using the mold base in which the notch portion is not formed, a transparent resin due to residual air is formed on the protruding portion. The top layer has been perceived. Thus, when a hollow portion occurs in the transparent resin top layer, the pitch width of the formed ridge is not constant, so there is a shift between the wavelength of the light to be demultiplexed and the wavelength of the demultiplexed light. Arise.
Example 3
In Example 2, a mold for thermal imprinting was formed in the same manner except that the depth of the notch was changed to 750 μm. The total of the area of the blank area and the area of the pattern area formed in the mold corresponds to 15 times the area where the uneven part is formed.

Using the mold produced as described above, a wavelength demultiplexing optical element was produced in the same manner as in Example 2. However, no chipping or distortion was observed in the formed pattern.
Example 4
In Example 2, the depth of the notch is set to 500 μm, and the total of the area of the blank area formed in the mold and the area of the pattern area is set to 5 times the area where the uneven part is formed. A mold for thermal imprinting was produced in the same manner as in Example 2.

Using the mold produced as described above, a wavelength demultiplexing optical element was produced in the same manner as in Example 2. However, no chipping or distortion was observed in the formed pattern.
Example 5
In Example 2, the depth of the notch was set to 500 μm, and the total of the area of the blank area formed in the mold and the area of the pattern area was set to 25 times the area where the uneven part was formed. A mold for thermal imprinting was produced in the same manner as in Example 2.

  Using the mold produced as described above, a wavelength demultiplexing optical element was produced in the same manner as in Example 2. However, no chipping or distortion was observed in the formed pattern.

[ Comparative Example 2 ]
In Example 2, the depth of the notch is set to 500 μm, and the total of the area of the blank area formed in the mold and the area of the pattern area is 35 times the area where the uneven part is formed. A mold for thermal imprinting was produced in the same manner as in Example 2.

A wavelength demultiplexing optical element was manufactured using the mold manufactured as described above in the same manner as in Example 2. However, the formed pattern was slightly distorted.
[Comparative Example 1]
In Example 2, the depth of the notch is 20 μm, and the total of the area of the blank area and the area of the pattern area formed in the mold is 15 times the area where the uneven part is formed. A mold for thermal imprinting was produced in the same manner as in Example 2.

Using the mold manufactured as described above, a wavelength demultiplexing optical element was manufactured in the same manner as in Example 2. Clearly, chipping and distortion were observed in the formed pattern.
The results of the above examples and comparative examples are shown in Table 1.

Ii) Evaluation method;
The pattern imprinted on the observation member by the optical microscope was visually evaluated on the member thermally printed using the obtained mold.
AA: There is no chipping or distortion of the pattern.
BB: Slight distortion of the pattern is seen.
CC: Patterns and distortion are clearly seen.
AA ^* : No chipping or distortion of the pattern is observed at all.

        However, the effective area of the pattern was reduced.

  In the imprint mold of the present invention, a notch for removing air between the substrate and the mold is formed on the outer side of the portion where the unevenness for forming the convex portion is formed on the optical element. . By forming the notch portion in this way, the substrate can be transferred to the surface of the transparent resin top layer of the transparent resin substrate by pressing the mold against the substrate and applying pressure to the substrate when it is heated. Since the air between the mold and the mold is smoothly removed, traces due to residual air hardly remain on the optical element, and an optical element with very high transfer accuracy can be obtained.

  Then, when using a mold having a notch for removing such residual air, the design value and the actual value are transferred by transferring the unevenness formed on the mold to the substrate even in the presence of air. A spectroscopic element such as a wavelength demultiplexing spectroscopic element that does not deviate from the demultiplexing wavelength can be easily manufactured.

FIG. 1 is a cross-sectional view showing an example of a cross section of an imprint mold of the present invention. FIG. 2 is a cross-sectional view showing another example of the cross section of the imprint mold of the present invention. FIG. 3 is a perspective view showing an example of a blank area formed in the mold of the present invention. FIG. 4 is a diagram illustrating an example of the unevenness formed in the imprint mold of the present invention. FIG. 5 is a diagram showing another example of the unevenness formed in the imprint mold of the present invention. FIG. 6 is a diagram showing an example when a spectroscopic element is manufactured using the imprint mold of the present invention. FIG. 7 is a view showing another example of a mode of manufacturing a spectroscopic element using the imprint mold of the present invention. FIG. 8 is an electron micrograph of a wavelength demultiplexing spectroscopic element manufactured using the imprint mold of the present invention, and (a) shows a wavelength manufactured by forming a notch in the imprint mold. (B) is an electron micrograph showing the surface state of a wavelength demultiplexing spectroscopic element manufactured using an imprint mold in which notches are not formed. FIG. 9 is an electron microscope showing a state in which traces of residual air are formed by enlarging the ends of the ridges of the wavelength demultiplexing spectroscopic element formed using the imprint mold in which notches are not formed. It is a photograph. FIG. 10A is an electron micrograph showing an enlarged ridge portion of a wavelength demultiplexing spectroscopic element formed using an imprint mold in which a notch is formed, and FIG. It is an electron micrograph which expands and shows the convex stripe part of the wavelength demultiplexing spectroscopy element formed using the mold for imprint in which the notch part is not formed. FIG. 11 is a cross-sectional view showing an example of a conventional imprint mold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Mold for imprint 12 ... Mold base 14 ... Convex part 16 ... Concave part 20 ... Notch part 23 ... Blank area 25 ... Blank area 30 ... Resin Substrate 31 ... Transparent resin top layer 35 ... Transparent resin intermediate layer 37 ... Transparent substrate layer 40 ... Resin substrate fixing base 50 ... Press base 60 ... Drive shaft

Claims (6)

The transfer part having a nano-order unevenness is provided in the substantially central part of the mold substrate, and the transfer part has a blank area in which no pattern is formed outside the pattern area. When the total of the area of the pattern region is within a range of 1.1 to 30 times the area of the pattern region, and the substrate that is the member to be transferred and the mold are in contact with the periphery of the transfer portion Further, in order to discharge the air between the substrate and the mold, there is a notch portion formed to be lower by 50 μm to 1 mm than the bottom portion of the concave portion formed in the mold. mold. High Saga of the blank area, the thermal imprint mold as in claim 1, wherein said that the bottom and the same height of the top portion or recess of the protrusion formed on the transfer unit.   2. The thermal imprint mold according to claim 1, wherein the mold substrate is formed of any one of hard members selected from the group consisting of silicon, quartz and glass. On the surface of the substrate
A substantially central portion of the motor Rudo substrate, using a transfer portion having irregularities corresponding to the protrusion comprising a plurality of unevenness of the nano-order formed on the substrate surface, the periphery of the transfer section and contacts the substrate and the mold In this case, in order to discharge the air between the substrate and the mold, the mold for thermal imprinting having a notch portion formed 50 μm to 1 mm lower than the bottom portion of the recess formed in the mold is heated. in contact with the irregularities formed on the mold is transferred to the substrate surface,
The transfer section has a blank area where no pattern is formed outside the pattern area, and the total area of the blank area and the area of the pattern area is 1.1 to 1.1 with respect to the area of the pattern area. A method for manufacturing an optical element, wherein the optical element is within a range of 30 times . The contact between the mold and the substrate, producing how the optical element according to claim 4, wherein, wherein the performing in an environment of 6Pa～101.3KPa. The optical element is manufactured how the optical element according to claim 4, wherein, wherein it is a wavelength division optical element.