PURPOSE: To fulfill a function corresponding to several optical branching and coupling devices, by use of one element, by providing 2 total reflection surfaces on a position where they have a constant angle and also do not cross to each other in the lengthwise direction, in the inside of a focusing optical transmission body.
CONSTITUTION: This device has a focusing optical transmission body 501 having the length of 1/2 pitch, and is provided with 2 total reflection films 801, 802 containing an optical axis which makes half of the length a boundary has relation of a relative position falling at right angles with each other to the right and left. Also, optical fibers 611W614, 621W624 and 711W714, 721W724 are placed so as to be almost parallel to the optical axis, and also on the surfaces which are positioned at an equal distance from the optical axis and have 22.5° angle against said 2 total reflection surfaces, therefore, for instance, a luminous flux from the optical fiber 611 is made to branch to the optical fibers 711W714 by a function of the 2 total reflection films, and a lumious flux from the optical fiber 621 is made to branch to the optical fibers 721W724.
AOKI SHIGEO
KAJITANI MITSUO
