| 摘要 |
PURPOSE:To obtain high optical attenuating efficiency by forming an optical attenuator in such a manner that the adjacent light transmitted through the many annular segments of a light transmittable medium have the effect of weakening each other. CONSTITUTION:The medium 10-1 is multi-divided on the concentrical circle at the radius r0=0, r1, r2- of the concentrical circle and is segmented to the same annular segments k0, k1, k2-. The adjacent segments k0, kx1, k2- are formed to the rugged step shape alternately to the thickness d1 and d2. The thickness difference d=d1-d2 between d1 and d2 is so set as to satisfy the equation. The incident light T is eventually shifted in the phase between the transmitted light T1 transmitted through the thickness d1 part and the transmitted light T2 transmitted through the thickness d2 part adjacent thereto by as much as (2m+1)lambda/2, i.e., 1/2 wavelength or the odd-times said wavelength (a phase difference of T1 and T2 arises). The light negate (weaken) consequently each other by the mutual interference and the medium 10-1 is capable of attenuating the beam 20 with extremely high efficiency. |
