| 摘要 |
PURPOSE:To average the spatial/temporal intensity, the phase and the direction of polarization of a beam by varying the scattering state of a dynamic scattering plate, returning the scattered light therefrom to an illumination optical system at are condensing section in order to recondensate and reuse, thereby imparting a random scattering to each point on the cross-section of the beam. CONSTITUTION:A dynamic scattering plate 2, movable in response to the operation of a driving section 4, is interposed between a condenser lens 1a and a collector lens 1b. A recondensing section 3 is also provided in order to condense the light scattered from the dynamic scattering plate 2 back to an illumination optical system. The recondensing section 3 increases the condensation rate by locating the focus thereof at the collector lens 1b. Furthermore, the factor for making uneven the spatial distribution of exposing illumination is weakened by enlarging the diameter of beam on the dynamic scattering plate 2. The dynamic scattering plate 2 imparts a random scattering to each point on the cross-section of beam thus averaging the spatial/temporal intensity, phase and the direction of polarization of the beam. |
