| 摘要 |
This polarization beamsplitter with a substrate-mode holographic structure is used to separate the s-polarization beam with p-polarization, and guide two separated beams at directions parallel to each other. The element consists of a pair of substrate-mode gratings with a specific designed diffraction angle and index modulation on a dielectric substrate. Through the input grating the normally incident beam with one polarization has zero diffraction efficiency and directly pass through the substrate; the beam with another polarization is diffracted at an angle exceeding the critical angle, then propagates through the substrate with total internal reflection to the output grating, and normally coupled out of the element. Thus, the beams with two different polarizations are separated, and two beams propagates at direction parallel to each other. The gratings suitable for infrared applications were formed with dichromated gelatin, and recorded by two free-space input beams with shorter wavelength recording technique.
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