| 摘要 |
PROBLEM TO BE SOLVED: To provide a data communication device wherein effective photo- detecting area is large, S/N ratio is good, and further light in the direction in a large area is allowed to be detected, and tolerance for communication destination selection is large. SOLUTION: This device is a deflection element which changes incident angle and output angle of light on a photodetecting device 32. At this time, a plurality of Bragg holograms (33-1)-(33-9) whose deflection incident angles are different from each other and whose deflection output angles are different from each other are assigned, so that infrared rays (34-1)-(34-9) entering from different directions are defected, and exiting is performed as infrared rays (35-1)-(35-9) in the range of a specified solid angle, with lines connecting the Bragg type holograms (33-1)-(33-9) and the photodetecting device 9 as centers. |
