| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical branching device wherein the uniformity of the intensity among mutual branched light beams is high, the diffraction efficiency is large, and the mutual positioning among an input optical system, a diffraction grating and an output optical system is easy. SOLUTION: The optical branching device 10 is provided with an input optical system 12 outputting parallel light beams, a diffraction grating 14 wherein variations of thickness imparting a phase difference to transmitting light beams are two-dimensionally distributed, the parallel light beams outputted from the input optical system 12 and inputted and diffracted and are branched into plural diffracted light beams mutually existing on the same plane and mutually advancing in the different direction, an output optical system 16 respectively inputting the diffracted light beams branched by the diffraction grating 14, and a substrate 18 having an input optical system placing area on which the input optical system 12 is placed, an output optical system placing area on which the output optical system 16 is placed and a diffraction grating placing area on which the diffraction grating 14 is placed. |
