Wavelength variable optical filter

Patent metadata

Field	Value
Publication number	US-12455442-B2
Application number	US-202017919959-A
Country	US
Kind code	B2
Filing date	Apr 21, 2020
Priority date	Apr 21, 2020
Publication date	Oct 28, 2025
Grant date	Oct 28, 2025

Abstract

A first component having a plate shape includes a first incident surface and a first emission surface disposed on the opposite side of the first incident surface. The first component is made of light transmissive material having an electrostrictive effect. The first component further includes a first transparent electrode formed on the first incident surface, and a second transparent electrode formed between the first emission surface and a first reflective film.

First claim

The invention claimed is:

1 . A wavelength variable optical filter comprising:
a first plate-like component made of a light transmissive material which has an electrostrictive effect, the first plate-like component including a first incident surface on a first side of the first plate-like component and a first emission surface on a second side of the first plate-like component, the first side of the first plate-like component being opposite to the second side of the first plate-like component; a second plate-like component made of a light transmissive material, the second plate-like component including a second incident surface on a first side of the second plate-like component and a second emission surface on a second side of the second plate-like component, the first side of the second plate-like component being opposite to the second side of the second plate-like component; a first reflective film on a side of the first emission surface and configured to partially reflect light transmitting through the first plate-like component; a first transparent electrode on the first incident surface; a second transparent electrode between the first emission surface and the first reflective film; and a second reflective film on the second incident surface and configured to partially reflect light transmitting through the second plate-like component, wherein the first reflective film and the second reflective film provide a Fabry-Perot interferometer.

2 . The wavelength variable optical filter according to claim 1 , wherein the first emission surface and the second incident surface face each other.

3 . The wavelength variable optical filter according to claim 1 , wherein the first incident surface and the first emission surface are parallel to each other.

4 . The wavelength variable optical filter according to claim 1 , wherein the second incident surface and the second emission surface are parallel to each other.

5 . The wavelength variable optical filter according to claim 1 , wherein a distance between the first transparent electrode and the second transparent electrode is smaller than a beam diameter of the light transmitting through the first plate-like component.

6 . The wavelength variable optical filter according to claim 1 , wherein the first plate-like component is made of KTN [KTa 1-α Nb α O 3 (0<α<1)] crystal or KLTN [K 1-β Li β Ta 1-α Nb α O 3 (0<α<1, 0<β<1)] crystal with lithium added.

7 . The wavelength variable optical filter according to claim 1 , wherein the second plate-like component is made of KTN [KTa 1-α Nb α O 3 (0<α<1)] crystal or KLTN [K 1-β Li β Ta 1-α Nb α O 3 (0<α<1, 0<β<1)] crystal with lithium added.

8 . The wavelength variable optical filter according to claim 1 , wherein the first transparent electrode and the second transparent electrode are made of indium tin oxide.

9 . The wavelength variable optical filter according to claim 1 , wherein:
the first incident surface, the first emission surface, the second incident surface and the second emission surface are disposed on an optical axis; and a distance between the first incident surface and the second incident surface on the optical axis is constant.

10 . A method of making a wavelength variable optical filter, the method comprising:
providing a first plate-like component made of a light transmissive material which has an electrostrictive effect, the first plate-like component including a first incident surface on a first side of the first plate-like component and a first emission surface on a second side of the first plate-like component, the first side of the first plate-like component being opposite to the second side of the first plate-like component; providing a second plate-like component made of a light transmissive material, the second plate-like component including a second incident surface on a first side of the second plate-like component and a second emission surface on a second side of the second plate-like component, the first side of the second plate-like component being opposite to the second side of the second plate-like component; forming a first reflective film on a side of the first emission surface, the first reflective film being configured to partially reflect light transmitting through the first plate-like component; forming a first transparent electrode on the first incident surface; forming a second transparent electrode between the first emission surface and the first reflective film; and forming a second reflective film on the second incident surface, the second reflective film being configured to partially reflect light transmitting through the second plate-like component, wherein the first reflective film and the second reflective film make a Fabry-Perot interferometer.

11 . The method according to claim 10 , wherein the first emission surface and the second incident surface face each other.

12 . The method according to claim 10 , wherein the first incident surface and the first emission surface are parallel to each other.

13 . The method according to claim 10 , wherein the second incident surface and the second emission surface are parallel to each other.

14 . The method according to claim 10 , wherein a distance between the first transparent electrode and the second transparent electrode is smaller than a beam diameter of the light transmitting through the first plate-like component.

15 . The method according to claim 10 , wherein the first plate-like component is made of KTN [KTa 1-α Nb α O 3 (0<α<1)] crystal or KLTN [K 1-β Li β Ta 1-α Nb α O 3 (0<α<1, 0<β<1)] crystal with lithium added.

16 . The method according to claim 10 , wherein the second plate-like component is made of KTN [KTa 1-α Nb α O 3 (0<α<1)] crystal or KLTN [K 1-β Li β Ta 1-α Nb α O 3 (0<α<1, 0<β<1)] crystal with lithium added.

17 . The method according to claim 10 , wherein the first transparent electrode and the second transparent electrode are made of indium tin oxide.

18 . The method according to claim 10 , wherein:
the first incident surface, the first emission surface, the second incident surface and the second emission surface are disposed on an optical axis; and a distance between the first incident surface and the second incident surface on the optical axis is constant.

Assignees

• Ntt Inc

Inventors

• Tanaka Yurina
• Akage Yuichi
• Ueno Masahiro
• Sakamoto Takashi
• KAWAMURA Sohan
• Oka Soichi

Classifications

• G02B26/007

  the movable or deformable optical element controlling the colour, i.e. a spectral characteristic, of the light · CPC title

• G02B26/001

  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

• G02F1/03

  based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect (G02F1/061 takes precedence) · CPC title

• G02B26/00

  Optical devices or arrangements for the control of light using movable or deformable optical elements (control of light by modification of the optical properties of the media of the elements involved therein G02F1/00) · CPC title

• G02B26/002 Primary

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