| 摘要 |
PROBLEM TO BE SOLVED: To obtain a floodlighting device which can projects floodlight with efficient distribution of light intensity without generating remarkable change of light intensity and interference fringes in a cross section perpendicular to an optical axis of the floodlight of long distance floodlighting and to obtain an optical communication system using the same. SOLUTION: The floodlighting device has a luminous section for emitting light of coherency and a floodlighting optical system and floodlights luminous flux in which distribution of light intensity in the effective cross section perpendicular to the optical axis decreases from the optical axis toward an outer peripheral direction. In this floodlighting device, when wave front aberration is made to be positive when wave front of the floodlight is located at a side of light proceeding direction than a reference spherical surface does in a state of the device when being used at a maximum floodlighting distance of specification and in case wave front aberration of 70% beams in the effective luminous flux cross section is negative at the wave front of the floodlight immediately after being emitted from the floodlighting device, variation of the wave front aberration in an outer peripheral direction of the luminous flux in an optional micro region is zero or negative as to the wave front aberration of from 70% beams to 100% beams. |
