| 摘要 |
PURPOSE:To realize apodization by making duty by projection and recess parts or the thickness of the projection parts locally. CONSTITUTION:The projection parts 12 and 12 have constant thickness (t), but vary in width D1 in a direction A and are smallest in width at both end parts and largest at the center parts. Further, the width D2 of the recess part 13 also varies and is smallest at both ends in the direction A and largest at the center part, and the duty varies in the direction shown by the arrow A. The intensity is suppressed below 10% at every position of a diffraction grating 10 corresponding to each duty value and incident light is split, so that 0-order light is obtained at the center part of the diffraction grating 10 and primary light is obtained at both end parts. Consequently, the intensity distribution of output light is controlled to split the incident light and also attain apodization at the same time. |
