Optical coupling system and optical communication device

Patent metadata

Field	Value
Publication number	US-12248179-B2
Application number	US-202418633938-A
Country	US
Kind code	B2
Filing date	Apr 12, 2024
Priority date	Oct 15, 2021
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

An object is to provide an optical coupling system having a simplified structure and a small size and an optical communication device using the optical coupling system. The object is achieved by an optical coupling system that couples a multi-core fiber and coupled devices to each other using a combination of a polarized light beam control element facing a light incident and emission surface of a multi-core fiber and a polarization-selective diffraction element that is positioned on a side of the polarized light beam control element opposite to the emission surface of the multi-core fiber and that faces the coupled devices.

First claim

What is claimed is:

1. An optical coupling system comprising:
a polarized light beam control element facing a light incident and emission surface of a multi-core fiber;
a polarization-selective diffraction element positioned on a side of the polarized light beam control element opposite to the emission surface of the multi-core fiber;
a plurality of coupled devices having light incident and emission surfaces facing the polarization-selective diffraction element;
an incidence side λ/4 wavelength plate positioned on a side of the polarized light beam control element opposite to the polarization-selective diffraction element; and
an emission side λ/4 wavelength plate positioned on a side of the polarization-selective diffraction element opposite to the polarized light beam control element.

2. The optical coupling system according to claim 1 ,
wherein the polarized light beam control element is a liquid crystal diffraction element including an optically anisotropic layer having a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one direction in plane.

3. The optical coupling system according to claim 2 ,
wherein the polarization-selective diffraction element is a liquid crystal diffraction element including an optically anisotropic layer having a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one direction in plane.

4. An optical communication device comprising:
the optical coupling system according to claim 2 .

5. The optical coupling system according to claim 2 ,
wherein the polarized light beam control element transmits incidence rays while converging or diverging the incidence rays depending on polarization.

6. The optical coupling system according to claim 5 ,
wherein the polarized light beam control element transmits incidence rays while converging or diverging the incidence rays depending on a rotation direction of circular polarization.

7. The optical coupling system according to claim 6 ,
wherein the polarized light beam control element comprises a concentric liquid crystal alignment pattern.

8. The optical coupling system according to claim 1 ,
wherein the polarization-selective diffraction element is a liquid crystal diffraction element including an optically anisotropic layer having a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one direction in plane.

9. An optical communication device comprising:
the optical coupling system according to claim 3 .

10. The optical coupling system according to claim 8 ,
wherein the polarization-selective diffraction element transmits incidence rays while converging or diverging the incidence rays depending on polarization.

11. The optical coupling system according to claim 10 ,
wherein the polarization-selective diffraction element transmits incidence rays while converging or diverging the incidence rays depending on a rotation direction of circular polarization.

12. The optical coupling system according to claim 11 ,
wherein the polarization-selective diffraction element comprises a concentric liquid crystal alignment pattern.

13. An optical communication device comprising:
the optical coupling system according to claim 1 .

Assignees

• Fujifilm Corp

Inventors

• Saitoh Yukito
• Kamo Makoto
• Sekiguchi Megumi
• Yanai Yujiro

Classifications

• G02B5/3016

  involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528) · CPC title

• G02B6/2773

  Polarisation splitting or combining · CPC title

• G02F1/13

  based on liquid crystals, e.g. single liquid crystal display cells · CPC title

• G02B5/30

  Polarising elements (light-modulating devices with active elements G02F1/00) · CPC title

• G02B5/18

  Diffraction gratings {(holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44)} · CPC title