US 11,454,770 B2 · Apparatus and method for adjusting optical axis for optical wireless communication in free space

Abstract

Provided are an apparatus and method for adjusting an optical axis. In the apparatus, an iris diaphragm and a quadrant photodiode (QPD) are used to align optical axes of an optical system of the apparatus so that optical transmission efficiency between an optical transmitter and an optical receiver can be increased. Since a hole of the iris diaphragm can be adjusted to be small, a beam larger than a light-receiving area of the QPD can be included in the light-receiving area, and optical axis alignment is facilitated accordingly. When the QPD and the iris diaphragm are applied to the apparatus, it is possible to simultaneously perform data transmission, tracking, and optical axis alignment. An optical fiber end surface and optical axes of lenses arranged in parallel are aligned in the apparatus so that alignment between two terminals can be easy and reception efficiency can be increased.

Claims15

Dependent claims

An apparatus for adjusting an optical axis for a first terminal and a second terminal which perform optical wireless communication in free space, the first terminal comprising:

a first light output device configured to output a first light, the second terminal comprising:
a second light output device configured to output a second light,
the first terminal further comprising:
a first iris diaphragm configured to adjust a beam size of the second light from the second light output device of the second terminal;
and
a first quadrant photodiode (QPD) configured to receive the second light whose beam size has been adjusted by the first iris diaphragm, and
the second terminal further comprising:
a second iris diaphragm configured to adjust a beam size of the first light from the first light output device of the first terminal;
and
a second QPD configured to receive the first light whose beam size has been adjusted by the second iris diaphragm,
wherein the first iris diaphragm adjusts the beam size of the second light to be smaller than a light-receiving area of the first QPD,
wherein the second iris diaphragm adjusts the beam size of the first light to be smaller than a light-receiving area of the second QPD, and
wherein the first output device comprises a movable optical fiber connector.

10 more elements

A method of adjusting an optical axis for a first terminal and a second terminal which perform optical wireless communication in free space, the method comprising:

outputting a first light from a first optical fiber end surface of the first terminal;
outputting a second light from a second optical fiber end surface of the second terminal;
receiving the second light output from the second optical fiber end surface by a first quadrant photodiode (QPD) of the first terminal;
receiving the first light output from the first optical fiber end surface by a second QPD of the second terminal;
adjusting a beam size of the second light received by the first QPD with a first iris diaphragm of the first terminal;
and
adjusting a beam size of the first light received by the second QPD with a second iris diaphragm of the second terminal,
wherein the first iris diaphragm adjusts the beam size of the second light to be smaller than a light-receiving area of the first QPD,
wherein the second iris diaphragm adjusts the beam size of the first light to be smaller than a light-receiving area of the second QPD, and
wherein the first optical fiber end surface is comprised in a movable connector.

7 more elements

Dependencies are inferred from the claim text.

Apparatus and method for adjusting optical axis for optical wireless communication in free space

Life of this patent

Apparatus and method for adjusting optical axis for optical wireless communication in free space

Life of this patent

Abstract

Claims15