| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a device for reducing speckles which can decrease the speckle pattern appearing on the illumination face to produce uniform illumination. SOLUTION: The laser light 1 with linearly polarized light having the polarization plane rotated by 45 deg. is made incident on a first polarization beam splitter 4-1 to be separated into the P polarized light component and S polarized light component. The P polarized light component is transmitted while the S polarized light component is reflected to equally separate the both polarized light components. The P polarized light component directly propagates while the S polarized light component is reflected by a return prism 6-1 to produce an optical path difference longer than the coherence length from the optical path length of the P polarized light, and both components are separately made a second polarization beam splitter 5-1. Thus, incoherent laser light 1 having two kinds of polarized light components with the optical path difference longer than the coherence length is obtained as the output from the second polarization beam splitter 5-1.</p> |
