Patent ID: 11940321
Assignee: FUJIKURA LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A photodetection device comprising:
first optical fibers;
a second optical fiber;
an optical combiner having:
an end face connected to an end face of each of the first optical fibers; and
another end face connected to an end face of the second optical fiber;

a first photodetector that detects an intensity of light propagating through at least one of the first optical fibers;
a second photodetector that detects Rayleigh scattering of light propagating through the second optical fiber; and
a calculator that calculates the intensity of light propagating in a predetermined direction through the first optical fibers or the second optical fiber, from a result of detection by the first photodetector and a result of detection by the second photodetector,
wherein
some, but not all, of the first optical fibers each have another end face that is optically coupled to a light source, and
the first photodetector detects the intensity of the light propagating through the first optical fibers that are not optically coupled to the light source.