CPC G01J 1/4228 (2013.01) [G01J 1/0425 (2013.01); G02B 6/4286 (2013.01); H01S 3/1306 (2013.01); H01S 3/2383 (2013.01); G02B 6/2808 (2013.01); G02B 6/429 (2013.01); H01S 3/0014 (2013.01); H01S 3/1305 (2013.01)] | 5 Claims |
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.
|