Wavelength variable interference filter and optical module

Patent metadata

Field	Value
Publication number	US-10746909-B2
Application number	US-201815896460-A
Country	US
Kind code	B2
Filing date	Feb 14, 2018
Priority date	Feb 28, 2017
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A wavelength variable interference filter includes: a first substrate on which a first reflection film is formed; and a second substrate that includes a movable portion on which a second reflection film facing the first reflection film is formed and a holding portion surrounding an outer circumference of the movable portion and holding the movable portion so that the movable portion is displaceable in a thickness direction of the second reflection film. The movable portion has long and short sides in a plan view. The holding portion includes a long-side holding portion formed along the long side and a short-side holding portion formed along the short side. The rigidity of the short-side holding portion is lower than the rigidity of the long-side holding portion.

First claim

What is claimed is:

1. A wavelength variable interference filter comprising:
a first substrate;
a first reflection film on the first substrate;
a second substrate opposing the first substrate, the second substrate being configured with:
a moveable member that is rectangular-shaped with a long side and a short side in a plan view, the long side being longer than the short side; and
a holding member surrounding an outer circumference of the movable member and holding the moveable member; and

a second reflection film on the second substrate, the second reflection film facing the first reflection film,
wherein the holding member includes a long-side holding member formed along the long side, and the holding member includes a short-side holding member formed along the short side,
a rigidity in a first direction along the long side of the short-side holding member is lower than a rigidity a second direction along the short side of the long-side holding member; and
wherein the rigidity of the long-side holding member is progressively lowered in the first direction as a distance from a normal of the long side passing through a center of the moveable member increases.

2. The wavelength variable interference filter according to claim 1 ,
wherein the rigidity of the long-side holding member is progressively lowered in a third direction along a major axis of the movable member as a distance from a normal of the major axis passing through a center of the movable member increases.

3. The wavelength variable interference filter according to claim 1 ,
wherein the rigidity of the short-side holding member is progressively lowered in the second direction as a distance from a normal of the short side passing through a center of the movable member increases.

4. The wavelength variable interference filter according to claim 1 ,
wherein the rigidity of the short-side holding member is progressively lowered in a third direction along a minor axis of the movable member as a distance from a normal of the minor axis passing through a center of the movable member increases.

5. The wavelength variable interference filter according to claim 1 ,
wherein the holding member further includes a corner holding member disposed between the long-side holding member and the short-side holding member in the plan view, and
wherein a rigidity of the corner holding member is lower than the rigidities of the long-side holding member and the short-side holding member.

6. The wavelength variable interference filter according to claim 5 ,
wherein the corner holding member is disposed in a region confined by a pair of lines formed along the long sides in contact with a first circumference of the long-side holding member close to the movable member and a first outer circumference opposite to the first circumference and a pair of lines formed along the short sides in contact with a second circumference of the short-side holding member close to the movable member and a second outer circumference opposite to the second circumference, and
wherein a rigidity in a fourth direction angled with respect to the first and second directions of the corner holding member is lower than the rigidities of the long-side holding member and the short-side holding member.

7. The wavelength variable interference filter according to claim 1 ,
wherein a thickness of the short-side holding member is less than a thickness of the long-side holding member.

8. The wavelength variable interference filter according to claim 1 ,
wherein a length of the short-side holding member in the first direction along the long side is greater than a length of the long-side holding member in the second direction along the short side.

9. The wavelength variable interference filter according to claim 1 ,
wherein a plurality of holes are formed in the holding member, and
wherein an opening area of the holes per unit area in the short-side holding member is greater than an opening area of the holes per unit area in the long-side holding member.

10. The wavelength variable interference filter according to claim 5 ,
wherein the holding member further includes a protruding holding member that protrudes from an outer circumference of the corner holding member.

11. A wavelength variable interference filter comprising:
a first substrate;
a first reflection film on the first substrate;
a second substrate opposing the first substrate; and
a second reflection film on the second substrate, and the second reflection film facing the first reflection film,
the second substrate including a movable member and a holding member, the holding member surrounding an outer circumference of the movable member and holding the movable member,
wherein the movable member includes a first side in a first direction and a second side in a second direction intersecting the first direction in a plan view, and
the holding member includes:
a first holding member formed along the first side,
a second holding member formed along the second side,
a corner holding member confined by a pair of lines formed in the first direction in contact with a first circumference of the first holding member close to the movable member and a first outer circumference opposite to the first circumference and a pair of lines formed along the second direction in contact with a second circumference of the second holding member close to the movable member and a second outer circumference opposite to the second circumference, and
a protruding holding member protruding from an outer circumference of the corner holding member.

12. The wavelength variable interference filter according to claim 11 ,
wherein the protruding holding member is continuous with at least one of a part of the first holding member and a part of the second holding member and protrudes in a direction away from the movable member.

13. An optical module comprising:
the wavelength variable interference filter according to claim 1 ; and
a light receiving unit that receives light transmitted through the wavelength variable interference filter.

14. An optical module comprising:
the wavelength variable interference filter according to claim 2 ; and
a light receiving unit that receives light transmitted through the wavelength variable interference filter.

15. An optical module comprising:
the wavelength variable interference filter according to claim 3 ; and
a light receiving unit that receives light transmitted through the wavelength variable interference filter.

16. An optical module comprising:
the wavelength variable interference filter according to claim 4 ; and
a light receiving unit that receives light transmitted through the wavelength variable interference filter.

17. An optical module comprising:
the wavelength variable interference filter according to claim 5 ; and
a light receiving unit that receives light transmitted through the wavelength variable interference filter.

18. An optical module comprising:
the wavelength variable interference filter according to claim 6 ; and
a light receiving unit that receives light transmitted through the wavelength variable interference filter.

Assignees

• Seiko Epson Corp

Inventors

• Sano Akira

Classifications

• G02B5/26 Primary

  Reflecting filters (G02B5/28 takes precedence) · CPC title

• G01J3/26

  using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters · CPC title

• G02B26/001 Primary

  based on interference in an adjustable optical cavity (interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26) · CPC title

• G02B5/284

  of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates (etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26) · CPC title

• G02B5/28 Primary

  Interference filters · CPC title