| 摘要 |
PURPOSE:To obtain a parallel flux having a uniform intensity distribution by dropping the diffraction efficiency in the center of a grading lens rather than in its vicinity. CONSTITUTION:The diffraction efficiency of a strong incident light part is dropped. To realize said dropping, the depth of a diffraction grating groove is made shallow. Namely, the depth is made gradually shallower toward center part 24 from periphery part 23. Thus Gauss type light beam having a light intensity distribution which is largest in the center of a light emitting source and gradually smaller toward the periphery can be shaped to a light beam with a uniform intensity. |
