To suppress attenuation of transmitted light by giving an optical guide a directivity with a simple configuration.
In an optical waveguide 2A, a second optical guide portion 2B having a different light-transmissivity is provided around the whole periphery of the side face of a first optical guide portion 20A having a cylindrical or a polygonal column shape, a beam splitter 22 is formed on the boundary face between the first optical guide portion 20A and the second optical guide portion 20B to reflect light at a predetermined rate and pass the rest of the light, and the light, which is made incident to the first optical guide portion 20A from a single direction or a plurality of different angles, is emitted to the circumferential direction of the second optical guide portion 20B with a single directivity or a plurality of directivities. A laser diode 3 which emits light toward the first optical guide portion 20A of the optical waveguide 2A is arranged at a predetermined angle around the outer periphery of the second optical guide portion 2B, and a photodetector 4 is arranged at a predetermined angle along the outer periphery of the second optical guide portion 2B on the basis of the directivity corresponding to the angle of the light which is made incident to the first optical guide portion 20A.
OZAKI NOZOMI
WADA SEIJI
SEKIYA TOSHIYUKI
HAYAKAWA TAKESHI
HARAOKA KAZUO
SAMUKAWA SHINJI
HATTORI MASAAKI
KANEKO NAOKI
KONDO TETSUJIRO
| JPH09270753A | 1997-10-14 | |||
| JPH04104694A | 1992-04-07 | |||
| JP2005003944A | 2005-01-06 | |||
| JP2004523781A | 2004-08-05 |