Wavelength variable optical filter

Patent metadata

Field	Value
Publication number	US-12117604-B2
Application number	US-202117558063-A
Country	US
Kind code	B2
Filing date	Dec 21, 2021
Priority date	Dec 24, 2020
Publication date	Oct 15, 2024
Grant date	Oct 15, 2024

Abstract

The wavelength variable optical filter includes a first substrate, a second substrate, and a bonding film, the bonding film is in contact with a first reflective film and a second reflective film to thus join the first substrate with the second substrate, the bonding film has transparency with respect to light of a predetermined wavelength range, and an optical path extending through the first reflective film, the bonding film, and the second reflective film has transparency with respect to light of the predetermined wavelength range and has no peak of transmittance with respect to a wavelength range measured by the wavelength variable filter.

First claim

What is claimed is:

1. A wavelength variable optical filter, comprising:
a first substrate including a first filter region and a first bonding region;
a second substrate including a second filter region and a second bonding region, and
a bonding film located between the first bonding region of the first substrate and the second bonding region of the second substrate, wherein
the first filter region and the second filter region correspond to a wavelength variable filter,
the first substrate includes a first base body and at least one first reflective film, the at least one first reflective film being located at the first base body within the first filter region and within the first bonding region,
the second substrate includes a second base body and at least one second reflective film, the at least one second reflective film being located on the second base body within the second filter region and within the second bonding region,
the bonding film is in contact with the first reflective film and the second reflective film, thereby bonding the first substrate with the second substrate,
the bonding film has transparency with respect to light in a predetermined wavelength range, and
an optical path extending through the first reflective film, the bonding film, and the second reflective film has transparency with respect to the light in the predetermined wavelength range, the optical path having no peak of transmittance with respect to a wavelength range measured by the wavelength variable filter.

2. The wavelength variable optical filter according to claim 1 , wherein
a film thickness of the bonding film is set, based on a formula below, to have a peak of the light in a wavelength band that is not included in a variable range of the peak wavelength of the wavelength variable filter,
Q=λ/ 4 n

where a film thickness of the bonding film is Q, a peak wavelength of the light is λ, and a refractive index of the bonding film is n.

3. The wavelength variable optical filter according to claim 1 , wherein
an alignment mark is provided in a region, overlapping in plan view with the bonding film, at at least one of the first substrate and the second substrate.

4. The wavelength variable optical filter according to claim 1 , wherein
a recessed portion is provided in a region, overlapping with an alignment mark, in a region, overlapping in plan view with the bonding film, at at least one of the first substrate and the second substrate.

Assignees

• Seiko Epson Corp

Inventors

• Matsushita Tomonori

Classifications

• G02B5/26

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

• G02B26/002 Primary

  the movement or the deformation controlling the frequency of light, e.g. by Doppler effect · CPC title

• G02B5/284 Primary

  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