Optical phase modulator
    1.
    发明公开
    Optical phase modulator 审中-公开
    Optischer Phasenmodulator

    公开(公告)号:EP1050775A1

    公开(公告)日:2000-11-08

    申请号:EP00303355.2

    申请日:2000-04-20

    IPC分类号: G02F1/1334 G02F1/29

    摘要: A phase modulator includes a lower layer of glass or silicon substrate containing a 1-D array of pixels (42) formed from either ITO or aluminium respectively. The substrate is covered by an upper glass plate coated uniformly with ITO to make one large transparent electrode. Polymer-dispersed LC composite material is sandwiched between these layers, the polymer-dispersed material containing a nematic LC (with positive dielectric). Figure 4a shows the bipolar director configuration within the droplets (40) in the field-off condition where the bipolar axis of each droplet is assumed to be randomly oriented. Light impinging on this material may encounter small enough scattering centres to be suitable for Rayleigh scattering. An applied electric field exerts an electric torque on the directors. This is balanced by an elastic torque generated by the distortion of the director pattern away from its equilibrium position. The balance of these two forces determines an equilibrium position of the director and a rotation of the bipolar axis towards an orientation normal to the plane of the SLM. The device is thus able to provide an analogue modulation of the refractive index, and hence phase delay, encountered by incoming light. Figure 4b shows the final switch configuration in which voltages of different magnitudes have been applied to different pixels (42) to produce several different regions (44) of PDLC, with different switch states, and hence a phase pattern suitable to defract light into first order spot with high efficiency.

    摘要翻译: 相位调制器包括分别由ITO或铝形成的包含1-D像素阵列(42)的玻璃或硅衬底的下层。 基板被用ITO均匀涂覆的上玻璃板覆盖以制造一个大的透明电极。 聚合物分散的LC复合材料夹在这些层之间,聚合物分散的材料含有向列型LC(具有正电介质)。 图4a示出了在每个液滴的双极轴被假定为随机取向的场关闭状态下液滴(40)内的双极导向器配置。 撞击这种材料的光可能会遇到足够小的散射中心,以适合瑞利散射。 施加的电场对董事施加电力矩。 这通过由导向器图案从其平衡位置的扭曲产生的弹性扭矩来平衡。 这两个力的平衡决定了导向器的平衡位置和双极轴线朝向垂直于SLM平面的方向的旋转。 因此,该装置能够提供由入射光遇到的折射率的模拟调制,并因此提供相位延迟。 图4b示出了其中不同幅度的电压已经被施加到不同像素(42)以产生PDLC的几个不同区域(44)的最终开关配置,具有不同的开关状态,因此适合于将光分解为一阶 现场高效率。