JP2011257662A5

JP2011257662A5 -

Info

Publication number: JP2011257662A5
Application number: JP2010133572A
Authority: JP
Filing date: 2010-06-11
Publication date: 2013-07-04
Anticipated expiration: 2030-06-11

Description

本発明の一側面としての回折光学素子は、互いに異なる屈折率を有し、互いの格子面及び格子壁面の各々が接するように配置された第１の回折格子及び第２の回折格子を備える回折光学素子であって、前記格子壁面毎に設けられた複数の遮光部材を有し、光軸を含む断面内において、前記格子壁面の延長線と前記遮光部材の前記光軸に近い方の端部の延長線との距離をｗＬ、前記格子壁面の延長線と前記遮光部材の他方の端部の延長線との距離をｗＨ、前記第１の回折格子及び前記第２の回折格子の格子ピッチをＰ、使用波長帯域における最小の波長をλ０、とする時、
ｗＨ＞ｗＬ≧０
０＜（ｗＨ＋ｗＬ）／Ｐ＜０．０５
０＜λ０＜ｗＨ
なる条件を満たすことを特徴とする。
本発明の他の側面としての回折光学素子は、光学系のレンズに用いられる回折光学素子であって、前記レンズの光軸を中心として同心円状に所定の格子ピッチで形成された第１の格子面及び第１の格子壁面を複数備えた第１の回折格子と、前記光軸を中心として同心円状に前記所定の格子ピッチで形成された第２の格子面及び第２の格子壁面を複数備え、該第２の格子面が前記第１の格子面と接し、かつ、該第２の格子壁面が前記第１の格子壁面と接するように設けられた第２の回折格子と、前記光軸を中心として同心円状に前記所定の格子ピッチで形成された複数の遮光部材と、を有し、前記第１の回折格子及び前記第２の回折格子は、互いに異なる屈折率を有して高屈折率領域及び低屈折率領域を構成し、前記光軸を含む前記レンズの断面において、前記第１の格子壁面及び該第１の格子壁面の延長線によって分けられた領域のうち、前記第１の格子壁面の位置を基準とした場合に前記高屈折率領域に配置された各々の前記遮光部材の幅ｗＨと、前記低屈折率領域に配置された該遮光部材の幅ｗＬは、以下の式（１）〜（３）を満たすことを特徴とする。
ｗＨ＞ｗＬ≧０ … （１）
０＜（ｗＨ＋ｗＬ）／Ｐ＜０．０５ … （２）
０＜λ０＜ｗＨ … （３）
ただし、Ｐは前記格子ピッチ、λ０は使用波長帯域における最小の波長であり、幅ｗＨ、ｗＨの方向は、前記延長線と直交する方向である。 A diffractive optical element according to one aspect of the present invention includes a first diffraction grating and a second diffraction grating that have different refractive indexes and are arranged so that each of a grating surface and a grating wall surface are in contact with each other. An optical element having a plurality of light shielding members provided for each of the grating wall surfaces, and an end of the light shielding member closer to the optical axis in the cross section including the optical axis. WL, the distance between the extension of the grating wall surface and the extension of the other end of the light shielding member, wH, and the grating pitch of the first diffraction grating and the second diffraction grating. P, when the minimum wavelength in the used wavelength band is λ0,
wH> wL ≧ 0
0 <(wH + wL) / P <0.05
0 <λ0 <wH
It satisfies the following condition.
A diffractive optical element according to another aspect of the present invention is a diffractive optical element used for a lens of an optical system, and is a first grating formed concentrically with a predetermined grating pitch around the optical axis of the lens. A first diffraction grating having a plurality of surfaces and first grating wall surfaces, and a plurality of second grating surfaces and second grating wall surfaces formed concentrically with the predetermined grating pitch around the optical axis. A second diffraction grating provided so that the second grating surface is in contact with the first grating surface, and the second grating wall surface is in contact with the first grating wall surface, and the optical axis is A plurality of light shielding members concentrically formed at the predetermined grating pitch as a center, and the first diffraction grating and the second diffraction grating have different refractive indexes and a high refractive index. A region having a low refractive index and a section of the lens including the optical axis. Each of the regions arranged in the high refractive index region when the position of the first grating wall surface is used as a reference among the first grating wall surface and the region divided by the extension line of the first grating wall surface. The width wH of the light shielding member and the width wL of the light shielding member disposed in the low refractive index region satisfy the following expressions (1) to (3).
wH> wL ≧ 0 (1)
0 <(wH + wL) / P <0.05 (2)
0 <λ0 <wH (3)
However, P is the grating pitch, λ0 is the minimum wavelength in the used wavelength band, and the directions of the widths wH and wH are perpendicular to the extension lines .

Claims

A diffractive optical element comprising a first diffraction grating and a second diffraction grating having refractive indexes different from each other and arranged such that each of a grating surface and a grating wall face each other ,
A plurality of light-shielding member provided et the before each Symbol grating wall surface,
The optical axis in including cross plane, before Symbol wL the distance between the extension line of the end of the closer to the optical axis extension line and the shielding member of lattice walls, said shielding an extension of the grating wall surface When the distance from the extension line of the other end of the member is wH, the grating pitch of the first diffraction grating and the second diffraction grating is P, and the minimum wavelength in the used wavelength band is λ0,
wH> wL ≧ 0
0 <(wH + wL) / P <0.05
0 <λ0 <wH
A diffractive optical element characterized by satisfying the following condition .

The diffractive optical element according to claim 1, wherein the light shielding member reduces total reflected light generated at a boundary between the first diffraction grating and the second diffraction grating.

3. The diffractive optical element according to claim 1, wherein each of the grating surface, the grating wall surface, and the light shielding member is disposed concentrically around the optical axis.

4. The diffractive optical element according to claim 1, wherein the light shielding member is disposed inside the first diffraction grating or the second diffraction grating. 5.

The light blocking member, according to claim 1, before in contact with the Symbol rated child faces and the front Symbol lattice wall, characterized in that it is disposed at a boundary between said first diffraction grating a second diffraction grating 4. The diffractive optical element according to any one of items 1 to 3.

A diffractive optical element according to any one of 請 Motomeko 1 to 5,
A refractive optical unit;
An optical system comprising:

A diffractive optical element according to any one of claims 1 to 5,
An optical system comprising: a stop disposed on a rear side of the diffractive optical element.

An optical apparatus comprising the optical system according to claim 6.

A diffractive optical element used for a lens of an optical system,
A first diffraction grating comprising a plurality of first grating surfaces and first grating wall surfaces formed concentrically with a predetermined grating pitch around the optical axis of the lens;
A plurality of second grating surfaces and second grating wall surfaces formed concentrically around the optical axis at the predetermined grating pitch, the second grating surface being in contact with the first grating surface; A second diffraction grating provided so that the second grating wall surface is in contact with the first grating wall surface;
A plurality of light shielding members formed concentrically with the predetermined lattice pitch around the optical axis,
The first diffraction grating and the second diffraction grating have a refractive index different from each other and constitute a high refractive index region and a low refractive index region,
In the cross section of the lens including the optical axis, the region of the first grating wall surface and an extension line of the first grating wall surface, where the position of the first grating wall surface is a reference. The width wH of each light shielding member arranged in the high refractive index region and the width wL of the light shielding member arranged in the low refractive index region satisfy the following formulas (1) to (3). A diffractive optical element.
wH> wL ≧ 0 (1)
0 <(wH + wL) / P <0.05 (2)
0 <λ0 <wH (3)
However, P is the grating pitch, λ0 is the minimum wavelength in the used wavelength band, and the directions of the widths wH and wH are perpendicular to the extension lines.

The diffractive optical element according to claim 9, wherein the light shielding member reduces total reflected light generated at a boundary between the first diffraction grating and the second diffraction grating.

The light shielding member is based on a position of the first grating wall surface in a region divided by the first grating wall surface and an extension line of the first grating wall surface in a cross section of the lens including the optical axis. 11. The diffractive optical element according to claim 9, wherein the diffractive optical element is disposed only in the high refractive index region.