| 摘要 |
PURPOSE:To reduce the size and weight of a polarizing beam splitter by making polarization and sepn. by using a phase type diffraction grating formed in a region where the difference of the diffraction efficiency between S polarized light and P polarized light is large. CONSTITUTION:The phase type diffraction grating 12 is obtd. by coating a material essentially consisting of a polymer (e.g.: polyvinyl carbazole) having a carbazole ring on a substrate 13, irradiating two beams of parallel light L1, L2 at an increased incident angle theta thereon and developing the same. The diffraction grating is so formed that the S polarized light and P polarized light are different in the diffraction efficiency, for example, the diffraction efficiency of the S polarized light is larger than the diffraction efficiency of the P polarized light. The S polarized light is then diffracted and the P polarized light is transmitted therethrough and therefore, the incident light is polarized and separated by the difference in the plane of the polarization thereof. The use of the grating 12 as the polarizing beam splitter is thereby permitted and the size and weight thereof are reduced; in addition, the surface is smooth and therefore, the polarizing beam splitter which does not require surface protection is obtd.
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