JP2010281877A - Optical element and optical system having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element in which application liquid hardly adheres to an edge surface functioning as an attaching holding part for attaching and holding an optical element to a lens barrel even if an optical surface is coated by a spin-coating method, thereby the optical element is highly accurately held in the lens barrel. <P>SOLUTION: The optical element has a fine uneven structure equal to or less than a visible region wavelength formed on one optical surface of light incident and exit surfaces. The fine uneven structure is formed employing the spin-coating method. The outer peripheral part of the optical element is formed into a step-shape with a level difference along an optical axis direction. Among a plurality of edge surfaces partly constituting the step-shape, and comprising surfaces vertical to the center axis of the optical element, the second or subsequent edge surface from the one optical surface side consists of an attaching and holding part when the optical element is held in the lens barrel. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical element and an optical system having the optical element, and, for example, an optical element in which a fine uneven structure having an antireflection function is provided on the surface (light incident / exit surface) of an optical member (transparent substrate) to effectively prevent reflection. It relates to an element.

  Conventionally, in an optical element using a translucent medium such as glass or plastic, surface treatment such as providing an antireflection film on a light incident / exit surface is performed in order to reduce light due to surface reflection. For example, a dielectric multilayer film is known as an antireflection film for visible light. The dielectric multilayer film is formed by forming a thin film of metal oxide or the like on the surface of the light-transmitting substrate by vacuum deposition or the like. Moreover, as an antireflection structure formed in an optical element, a fine concavo-convex structure having a wavelength of visible light (wavelength 400 nm to 700 nm) or less is known (Patent Documents 1 to 3).

JP-A-9-202649 JP 2005-157119 A JP 2006-10831 A

  When a fine concavo-convex structure having a wavelength equal to or smaller than the wavelength of visible light is formed on the optical surface (lens surface), an antireflection effect with good incident angle characteristics can be obtained in a relatively wide wavelength region. In Patent Document 1, a fine concavo-convex structure of petal-like alumina is formed using a sol-gel method. And in order to form a fine concavo-convex structure on a lens surface, a sol solution is applied on the lens. Generally, as a method for applying a sol solution to a lens surface, a spin coating method that is a wet method is used. The spin coating method is a method in which a substrate is rotated and a coating solution is applied to the substrate surface by centrifugal force, and the coating solution can be uniformly coated on the substrate surface.

  By the way, the lens (optical element) is processed and polished so that the optical surface of the cut material becomes a desired curved surface, and then the centering and the chamfering of the outer peripheral portion are made so that the optical axis coincides with the central axis of the lens outer shape. It is made by processing. An attachment holding portion for attaching and holding the optical element to a lens barrel (lens barrel) is formed on the chamfered portion of the outer peripheral portion of the lens. In many optical elements, the mounting holding portion often uses the edge of the optical element. As an anti-reflective structure, when coating is applied to the lens surface using a spin coating method to form a fine concavo-convex structure (thin film), the coating liquid spreading from the lens surface due to centrifugal force reaches the edge of the optical element. May adhere. If the edge surface to which the coating liquid adheres is used as an attachment holding portion and is held in the lens barrel, the mounting stability of the optical element is deteriorated, for example, the optical element is eccentric in the lens barrel. When a lens barrel including such an optical element is used in an imaging apparatus, the optical performance is greatly deteriorated. For this reason, it is important for obtaining high optical performance to prevent the coating liquid from adhering to the edge surface serving as the mounting holding portion of the optical element so as to improve the mounting accuracy of the optical element to the lens barrel.

  The present invention provides an optical device capable of holding an optical element with high accuracy on a lens barrel, with almost no coating liquid adhering to the edge surface serving as an attachment holding portion even when the optical surface is coated by a spin coating method. An object is to provide an element and an optical system having the element.

  The optical element of the present invention is an optical element in which a fine concavo-convex structure having a wavelength of less than or equal to a visible wavelength is formed on one optical surface of the light incident / exit surface, and the fine concavo-convex structure is obtained using a spin coating method. The outer peripheral portion of the optical element is formed of a stepped shape having a step along the optical axis direction, and forms a part of the stepped shape from a surface perpendicular to the central axis of the optical element. Among the plurality of edge surfaces, one edge surface after the second optical surface counted from the one optical surface side is characterized by comprising an attachment holding portion for holding the optical element in the lens barrel.

  According to the present invention, the optical element can be held in the lens barrel with high accuracy, with almost no coating liquid adhering to the edge surface serving as the attachment holding portion even when the optical surface is coated by spin coating. An optical element that can be obtained is obtained.

Schematic sectional view showing an embodiment of the optical element of the present invention Jig installation situation explanatory drawing in the case of applying sol liquid to a permeable substrate which is an example of the optical element of the present invention Schematic sectional view of the optical element of Example 1 of the present invention FIG. 3 is an explanatory diagram of a jig installation situation when a sol solution is applied to a transmission substrate of the optical element of Example 1 of the present invention. Schematic sectional view of the optical element of Example 2 of the present invention Jig installation situation explanatory drawing in the case of applying sol liquid to the transmissive substrate of the optical element of Example 2 of the present invention Configuration diagram of the imaging optical system of Example 3 of the present invention Schematic sectional view of the optical element of Comparative Example 1 Jig installation situation explanatory drawing in the case of applying sol liquid to the transmissive substrate of the optical element of Comparative Example 1

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the optical element of the present invention, a fine concavo-convex structure having a wavelength less than or equal to the visible wavelength is formed on one of the light incident / exit surfaces (lens surface) using a spin coating method. . The outer peripheral portion of the optical element has a stepped shape with a step along the optical axis direction. In the stepped shape, an edge surface composed of a surface perpendicular to the center axis of the optical element and an edge portion composed of a surface parallel or inclined to the center axis of the optical element are alternately repeated along the optical axis direction. Is formed. Among the plurality of edge surfaces, the second and subsequent edge surfaces counted from one optical surface side on which the fine concavo-convex structure is formed are attached and held when the optical element is held in the lens barrel (lens barrel). Part (lens holding part).

  FIG. 1 is a schematic sectional view showing Example 1 of the optical element (lens) of the present invention. In FIG. 1, for easy understanding, a fine concavo-convex structure composed of a plurality of concavo-convex portions having a pitch of a wavelength in the visible region (wavelength 400 nm to 700 nm) or less is enlarged and deformed. In FIG. 1, reference numeral 1 denotes an optical element (lens). The optical element 1 has a fine concavo-convex structure 12 on a concave optical surface (lens surface) R1 of a transmissive substrate 11 having a meniscus lens shape. R2 is a convex optical surface (lens surface) opposite to the optical surface R1 of the transmissive substrate 11. L is the central axis (optical axis) of the optical element 1. S is the maximum outer diameter portion of the maximum outer diameter D of the optical surface R1. a is an edge surface that vertically connects the maximum outer diameter portion S of the optical surface R1 of the transmissive substrate 11 to the central axis L of the optical element 1; b is an edge surface provided in parallel with the edge surface a on the optical surface R2 side one step lower. c is an edge portion falling perpendicularly from the edge surface a to the edge surface b (parallel to the central axis L), and corresponds to the first when counted from the optical surface R1 side. d is an edge portion provided at a right angle (parallel to the central axis L) from the edge surface b to the end of the optical surface R2. Of the plurality of edge surfaces, one edge surface after the second optical surface R1 from the optical surface R1 side, in this embodiment, the edge surface b is a reference surface (mounting and holding) when the transparent substrate 11 is mounted in the lens barrel. Part). The edge surface a, the edge surface b, the edge portion c, and the edge portion d form part of the stepped shape of the outer peripheral portion of the optical element 1.

  FIG. 2 is a schematic diagram of a jig installation state when a sol solution is applied as a coating solution on the optical surface R1 of the transmissive substrate 11 of Example 1 shown in FIG. 1 by a spin coating method. . In FIG. 2, reference numeral 23 denotes a rotary stage on which the transmissive substrate 11 is set during spin coating. T is a rotation axis in the rotation stage 23 at the time of spin coating. The transmissive substrate 11 is held on the rotary stage 23 by a vacuum chuck during spin coating. At that time, the center axis L of the transmissive substrate 11 and the rotation axis T of the spin coat rotating stage 23 are held so as to coincide with each other. The edge d of the transmissive substrate 11 is in contact with the peripheral part 23 a of the rotary stage 23. A sol solution is dropped on the optical surface R1 of the transparent substrate 11 held on the rotary stage 23, the rotary stage 23 is rotated, and spin coating is performed. The dropped sol solution is spread toward the maximum outer shape S of the optical surface R1 of the transparent base material 11 by spin force and spin coated. The sol that has spread to the maximum outer shape S of the optical surface R1 is transmitted to the edge surface a and scattered.

The width (length in the direction perpendicular to the center axis L) Db of the edge surface b, which is the attachment holding portion of the transparent base material 11, is the length (length in the direction parallel to the center axis L) Dc of the edge portion c.
0.5 <Dc / Db (1)
Satisfied. By specifying the edge surface b and the edge portion c so as to satisfy the conditional expression (1), the edge surface b, which is the attachment holding portion, becomes a shadow of the edge portion c, and an area where the sol solution does not adhere can be secured. It becomes easy. On the other hand, if the viscosity of the coating solution is too large, the sol solution adhering to the edge portion c becomes thick and the mounting accuracy is deteriorated. Furthermore, the rotation speed at the time of spin coating is determined by the viscosity of the coating solution and the film thickness to be produced. Considering these matters, the viscosity v (mP · s) of the coating liquid used when the layer having the fine concavo-convex structure 12 formed on the optical surface R1 is
1 ≦ v ≦ 100 (2)
It is preferable to satisfy. The spin coater rotation speed R (rpm) at the time of producing the layer formed of the fine concavo-convex structure 12 is
1000 ≦ R ≦ 10000 (3)
It is preferable to satisfy. More preferably, 2000 ≦ R ≦ 7000 (3a)
It is preferable to satisfy.

  Although the structure of the fine concavo-convex structure 12 in the present embodiment is not particularly limited, for example, a structure containing aluminum or aluminum oxide can be applied. As the transmissive substrate 11 used in this embodiment, for example, there is a glass lens having an optical surface R1 having an opening angle of 30 degrees or more. Here, the open angle is an angle at which the effective diameter of the optical surface extends around the center of curvature. Furthermore, the present invention can be applied to an imaging device and an observation optical system that are used at wavelengths in the visible region (wavelength 400 nm to 700 nm) and infrared region (wavelength 700 nm to 900 nm). In addition, the present invention can also be applied to an optical system for an optical device such as a laser beam printer for image reading and an optical system for a projector.

  Hereafter, the structure of the optical element of each Example of this invention is demonstrated concretely. However, the present invention is not limited to such examples, and various modifications and changes can be made within the scope of the gist.

[Example 1]
FIG. 3 is a cross-sectional view of an essential part of the optical element according to the first embodiment of the present invention. The shapes of the edge surfaces f1 and f2 and the edge portions k1 and k2 of the optical element 21 in FIG. 3 are the same as those in FIG. The optical element 21 shown in FIG. 3 has a meniscus shape. On the optical surface R <b> 1 of the optical element 21, a fine uneven structure body (film) 22 having a fine uneven shape having a use wavelength (400 nm to 700 nm) or less is formed. In FIG. 3, the radius of curvature of the concave optical surface R1 on which the fine concavo-convex structure 22 is formed is r1. The radius of curvature of the convex optical surface R2 is r2. L is the central axis of the optical element 21. e is an edge end (maximum outer diameter portion) of the edge surface which is the outermost periphery of the optical surface R1 on which the fine concavo-convex structure 22 is formed.

  f1 is an edge surface connected perpendicularly to the edge e of the optical surface R1 and the central axis L. Reference numeral f2 denotes an edge surface which is arranged lower than the edge surface f1 by a height (length in the direction of the central axis L) Dk1 on the optical surface R2 side. The edge surface f2 serves as an attachment holding portion for the meniscus optical element 21. The widths of the edge surface f1 and the edge surface f2 are Df1 and Df2, respectively. The lengths (heights) of the edge part k1 and the edge part k2 are Dk1 and Dk2, respectively. The curvature radius r1 of the optical surface R1 of the optical element 21 is 35.0 mm, and the curvature radius r2 of the optical surface R2 is 80 mm. The center thickness m1 of the optical element 21 is 3 mm. The maximum outer diameter D1 of the optical surface R1 is φ46.0 mm. The maximum outer diameter D2 of the optical surface R2 is 60.0 mm. The width Df1 of the edge surface f1 is 3 mm, and the width Df2 of the edge surface f2 is 4 mm. The edge portion k1 has a height Dk1 of 3 mm, and the edge portion k2 has a height Dk2 of 2.8 mm.

  FIG. 4 shows the case where the optical element 21 of Example 1 shown in FIG. 3 is placed on a vacuum spin coat rotation stage 33 and the fine concavo-convex structure (thin film) 22 is formed on the optical surface R1 by the spin coat method. FIG. A fine concavo-convex structure body 22 having a fine concavo-convex shape was formed by spin coating on the optical surface R1 of the optical element 21 of Example 1 by the following method. After cleaning the optical element 21 with pure water rinse and alcohol, the optical surface R1 is placed on the vacuum chuck rotary stage 33 with the optical surface R1 facing upward. Then, an appropriate amount of a coating solution containing aluminum oxide was dropped, rotated at 3000 rpm for 30 seconds, and baked in an oven at 400 degrees for 1 hour.

  Next, it was immersed in hot water of 100 ° C. for 30 minutes and then dried to produce a fine concavo-convex structure (thin film) 22 made of a fine concavo-convex shape body mainly composed of aluminum oxide. When the edge surfaces f1 and f2 of the optical element 21 having the fine uneven structure 22 formed on the optical surface R1 are observed, the uneven surface 22 made of a fine uneven structure mainly composed of aluminum oxide is formed on the edge surface f1. The adhesion of was confirmed. No adhesion of the fine concavo-convex structure (thin film) 22 made of a fine concavo-convex shape body mainly composed of aluminum oxide was observed on the edge surface f2, which is an attachment holding portion of the optical element 21.

[Example 2]
FIG. 5 is a schematic configuration diagram of an optical element according to Embodiment 2 of the present invention. Example 2 of FIG. 5 is different from Example 1 of FIG. 3 in that a stepped shape is formed by further providing one step portion on the outer peripheral portion of the optical element 31. The shapes of the edge surfaces f3 and f4 and the edge portions k3 and k4 of the optical element 31 in FIG. 5 are the same as those in FIG. The edge surface f5 is formed of a surface provided in parallel with the edge surface f4 by one step (length DK4) lower on the optical surface R2 side. The edge portion k5 is formed of a surface provided with a length Dk5 parallel to the central axis L from the edge surface f5. The optical element 31 shown in FIG. 5 has a meniscus shape. On the optical surface R <b> 1 of the optical element 31, a fine concavo-convex structure 32 having a fine concavo-convex shape that is equal to or shorter than the operating wavelength is formed. In FIG. 5, the radius of curvature of the optical surface R1 on which the fine relief structure 32 is formed is r3. The radius of curvature of the convex optical surface R2 is r4. L is the central axis of the optical element 31.

  g is an end of the edge surface f3 which is the outermost periphery of the optical surface R1 on which the fine concavo-convex structure 32 is formed. f3 is an edge surface connected perpendicularly to the edge g of the optical surface R1 and the center axis L. Reference numeral f4 denotes an edge surface that is arranged lower than the edge surface f3 by a height Dk3 on the optical surface R2 side. Reference numeral f5 denotes an edge surface that is arranged lower than the edge surface f4 by a height Dk4 on the optical surface R2 side. The third and third edge surfaces f5 counted from the optical surface R1 side serve as attachment and holding portions for the meniscus optical element 31. The widths of the edge surface f3, edge surface f4, and edge surface f5 are Df3, Df4, and Df5 in this order. The lengths (heights) of the edge part k3, the edge part k4, and the edge part k5 are Dk3, Dk4, and Dk5 in this order. The curvature radius r3 of the optical surface R1 of the optical element 31 is 28.0 mm, and the curvature radius r4 of the optical surface R2 is 80 mm. The center thickness m2 of the optical element 31 is 3 mm. The maximum outer diameter D3 of the optical surface R1 is φ46.0 mm. The maximum outer diameter D4 of the optical surface R2 is 60.0 mm. The edge surface f3 has a width Df3 of 2 mm, the edge surface f4 has a width Df4 of 2 mm, and the edge surface f5 has a width Df5 of 3 mm. The edge portion k3 has a height Dk3 of 3 mm, the edge portion k4 has a height Dk4 of 3 mm, and the edge portion k5 has a height Dk5 of 3.2 mm.

  FIG. 6 shows a case where the optical element 31 of Example 2 shown in FIG. 5 is installed on a vacuum spin coat rotation stage 43 and a fine concavo-convex structure (thin film) 32 is formed on the optical surface R1 by spin coating. FIG. A fine concavo-convex structure (thin film) 32 having a fine concavo-convex shape was formed by spin coating on the optical surface R1 of the optical element 31 of Example 2 by the following method. After cleaning the optical element 31 with pure water rinse and alcohol, the optical surface R1 is placed on the vacuum chuck rotary stage 43 with the optical surface R1 facing upward. Then, an appropriate amount of a coating solution containing aluminum oxide was dropped, rotated at 3000 rpm for 30 seconds, and baked in an oven at 400 degrees for 1 hour. Next, it was immersed in hot water of 100 ° C. for 30 minutes and then dried to produce a fine concavo-convex structure (thin film) 32 having a fine concavo-convex shape mainly composed of aluminum oxide. When the edge surfaces f3, f4, and f5 of the optical element 31 having the fine uneven structure 32 formed on the optical surface R1 were observed, it was confirmed that the fine uneven structure 31 mainly composed of aluminum oxide was attached to the edge surface f3. It was done. No adhesion of the fine concavo-convex structure (thin film) 32 mainly composed of aluminum oxide was observed on the edge surface f5, which is an attachment holding portion of the optical element 31.

[Example 3]
FIG. 7 is a schematic view of the essential portions of Example 3 in which the optical element of the present invention is used in an imaging optical system. FIG. 7 is a cross-sectional view of the main part of an imaging optical system used in an imaging apparatus such as a camera. In FIG. 7, reference numeral 710 denotes an imaging optical system. Reference numeral 701 denotes a holding jig used when the lens (optical element) 700 is incorporated into the lens barrel. Reference numeral 711 denotes an optical surface provided with a fine uneven structure (thin film) having a fine uneven shape. In the present embodiment, the step of producing the fine concavo-convex structure 711 having the fine concavo-convex shape on the optical surface includes coating by spin coating of a sol solution. The use wavelength region of the optical system of the present embodiment is a visible region (wavelength 400 nm to 700 nm) and an infrared region (wavelength 700 nm to 900 nm). The open angle of the optical surface R1 of the optical element (lens) 700 constituting the optical system of this example and having the fine concavo-convex structure 711 is 30 degrees or more. In FIG. 7, the outer peripheral portion of the optical element 700 having the optical surface R1 on which the fine concavo-convex structure 711 is formed is stepped from the optical surface R1 to the optical surface R2. And the edge surface 702 used as an attachment holding | maintenance part is an edge shape (stepped shape) which exists in the position lower on the optical surface R2 side than the edge surface 703 which exists in the optical surface R1 side.

[Comparative Example 1]
FIG. 8 is a sectional view of an essential part of an optical element 41 according to Comparative Example 1 of the present invention. The optical element 41 of Comparative Example 1 has a meniscus shape, and a fine concavo-convex structure 42 is formed on a concave optical surface R1. On the optical surface R1 of the optical element 41 shown in FIG. In FIG. 8, the radius of curvature of the optical surface R1 on which the fine concavo-convex structure 42 is formed is r5. The radius of curvature of the other convex optical surface R2 is r6. L is the central axis of the optical element 41. h is an end of the edge surface f6 which is the outermost periphery of the optical surface R1. The edge surface f6 is an edge surface having a width Df6 that connects the center axis L and the edge h of the optical surface R1 vertically. k6 is an edge portion having a height Dk6. The edge surface f6 becomes an attachment holding part of the optical element 41. The curvature radius r5 of the optical surface R1 is 35.0 mm, and the curvature radius r6 of the optical surface R2 is 80 mm. The center thickness m3 of the optical element 41 is 3 mm. The maximum outer peripheral diameter D5 of the optical surface R1 is φ46.0 mm, and the maximum outer peripheral diameter D6 of the optical surface R2 is φ60.0 mm. The edge surface f6 has a width Df6 of 7 mm, and the edge portion k6 has a height Dk6 of 5.8 mm.

  FIG. 9 shows a fine concavo-convex structure (thin film) 42 having a fine concavo-convex shape formed by placing the optical element 41 of Comparative Example 1 shown in FIG. 8 on a vacuum spin coat rotation stage 53 and spin coating the optical surface R1. It is the schematic in the case of producing. A fine concavo-convex structure (thin film) 42 was formed by spin coating on the optical surface R1 of the optical element 41 of Comparative Example 1 by the following method. After cleaning the optical element 41 with pure water rinse and alcohol, the optical surface R1 was placed on a vacuum chuck rotary stage with the optical surface R1 facing upward. Thereafter, an appropriate amount of a coating solution containing aluminum oxide was dropped, rotated at 3000 rpm for 30 seconds, and baked in an oven at 400 degrees for 1 hour.

  Next, it was immersed in hot water of 100 ° C. for 30 minutes and then dried to produce a fine concavo-convex structure (thin film) 42 having a fine concavo-convex shape mainly composed of aluminum oxide. When the edge surface f6 of the optical element 41 having the fine uneven structure 42 formed on the optical surface R1 is observed, the edge surface f6 that is an attachment holding portion of the optical element 41 has a fine uneven structure body mainly composed of aluminum oxide. Many adhesions of (thin film) 42 were confirmed. When the meniscus optical element 41 of the comparative example was attached to the lens barrel and the optical performance was confirmed, the deterioration of the lens performance (optical performance) was confirmed.

  As described above, according to the present invention, when the outer peripheral portion of the optical element is formed into a stepped shape, the coating liquid spread by centrifugal force is applied when the lens surface of the optical element is applied by spin coating. It does not adhere to the edge surface and the optical element mounting stability does not deteriorate. For this reason, the stable optical element excellent in mass productivity can be provided.

11, 21, 31, and 41 are transmissive substrates, 12, 22, 32, and 42 are fine concavo-convex structures having fine concavo-convex shapes, 23, 33, 43, and 53 are rotary stages, R1 is an optical surface (coating surface), R2 is an optical surface, s, e, g, and h are edges on the R1 surface side of the edge of the edge that is the maximum outer periphery, L is a central axis, T is a rotation axis, and a, f1, f3, and f6 are optical surfaces. Edge surfaces b, f2, f4, f5 formed from the end on the R1 side are edge surfaces other than the edge surface formed from the end on the optical surface R1, c, d, k1, k2, k3, k4, k5. k6 is an edge portion, D1, D3, and D5 are effective diameters of the optical surface R1, D2, D4, and D6 are effective diameters of the optical surface R2, m1, m2, and m3 are center thicknesses of the optical elements, and r1 is the curvature of the optical surface R1. Radius, r2 is the radius of curvature of the optical surface R2, 700 is the optical element, and 701 is the suppression when the optical element is incorporated into the lens barrel. Jig, 711 is a surface provided with a fine concavo-convex structure having a fine concavo-convex shape, 702 is a lens holding surface when the optical element is incorporated into the lens barrel, 703 is an edge surface formed from the optical surface R1 side end, and 710 is Imaging optical system

Claims (10)

  An optical element in which a fine concavo-convex structure having a wavelength of less than or equal to a visible wavelength is formed on one optical surface of a light incident / exit surface, and the fine concavo-convex structure is formed using a spin coat method, The outer peripheral portion of the element has a stepped shape with a step along the optical axis direction, and forms a part of the stepped shape, out of a plurality of edge surfaces composed of surfaces perpendicular to the central axis of the optical element The optical element is characterized in that the second and subsequent edge surfaces counted from the one optical surface side comprise an attachment holding portion for holding the optical element in the lens barrel.   In the stepped shape, an edge surface composed of a surface perpendicular to the central axis of the optical element and an edge portion composed of a surface parallel to the central axis of the optical element are alternately arranged along the optical axis direction. 2. The optical element according to claim 1, wherein the optical element is formed repeatedly. The attachment holding portion is a second edge surface counted from the one optical surface side, the width of the second edge surface is Db, and the height of the first edge portion counted from the one optical surface side. Is Dc,
0.5 <Dc / Db
The optical element according to claim 1, wherein the following condition is satisfied. The fine concavo-convex structure has a coating solution viscosity of v (mP · s),
1 ≦ v ≦ 100
The optical element according to any one of claims 1 to 3, wherein the optical element is manufactured using a coating liquid that satisfies the following conditions. When the fine concavo-convex structure has a spin coater rotation speed of R (rpm),
1000 ≦ R ≦ 10000
The optical element according to any one of claims 1 to 4, wherein the optical element is manufactured by a spin coating method that satisfies the following conditions.   The optical element according to any one of claims 1 to 5, wherein the fine concavo-convex structure contains aluminum or aluminum oxide.   The optical element according to claim 1, wherein an opening angle of one optical surface of the optical element is 30 degrees or more.   An optical system comprising the optical element according to claim 1.   The optical system according to claim 8, wherein the optical system is an imaging optical system.   An optical apparatus comprising the optical system according to claim 8.