| 摘要 |
PURPOSE:To improve the utilization efficiency of light more. CONSTITUTION:Those device have a light source 1 arranged nearby the focus position of a parabolic reflecting mirror 2, a lambda/4 optical phase plate 3 on which the luminous flux from the light source 1 is made incident directly or through the parabolic reflecting mirror 2, and a polarization beam splitter 4 which transmits the P-polarized light component LP of the luminous flux emitted from the lambda/4 optical phase plate 3 and reflects the S-polarized light component LS. On the side where the S-polarized light component LS of the polarization beam splitter 4 is obtained by reflection, a corner cube array 5 which constitutes a retroreflection surface is provided. The S-polarized light component LS which is made incident on the corner cube array 5 is reflected in parallel to the incidence direction and returns to the light source 1. When the S-polarized light component LS returning to the light source 1 is made incident on the polarization beam splitter 4 again, it is converted by the lambda/4 optical phase plate 3 into a P-polarized light component LP, which is transmitted through the polarization beam splitter 4. |
