Multi-element grating beam splitter with a reflection grating element
for use in front facet substraction
    21.
    发明授权
    Multi-element grating beam splitter with a reflection grating element for use in front facet substraction 失效
    具有反射光栅元件的多元素光栅分束器,用于前小面减小

    公开(公告)号:US5511059A

    公开(公告)日:1996-04-23

    申请号:US259587

    申请日:1994-06-14

    摘要: A multi-element grating beam splitter with a reflection grating for use in providing a front facet detector signal in an optical system. The multi-element grating beam splitter includes first, second, third, and fourth grating elements for separating a return beam reflected and diffracted from a data track on an optical storage medium into first, second, third and fourth portions, respectively. The grating beam splitter also includes a fifth grating element, which is preferably a reflection grating, for directing a portion of an incident radiation beam onto a front facet detector. The front facet detector signal may be subtracted from a data signal resulting from detection of the first, second, third and fourth portions of the return beam in order to limit the effect of optical source noise on the data signal.

    摘要翻译: 具有反射光栅的多元素光栅分束器,用于在光学系统中提供前刻面检测器信号。 多元素光栅分束器包括第一,第二,第三和第四光栅元件,用于将从光学存储介质上的数据轨道反射和衍射的返回光束分别分离成第一,第二,第三和第四部分。 光栅分束器还包括第五光栅元件,其优选地是反射光栅,用于将入射辐射束的一部分引导到前刻面检测器上。 可以从由返回波束的第一,第二,第三和第四部分的检测产生的数据信号中减去前刻面检测器信号,以限制光源噪声对数据信号的影响。

    Method and apparatus for amplitude modulation of a laser beam
    22.
    发明授权
    Method and apparatus for amplitude modulation of a laser beam 失效
    激光束幅度调制方法和装置

    公开(公告)号:US5412743A

    公开(公告)日:1995-05-02

    申请号:US163206

    申请日:1993-12-06

    IPC分类号: G02B6/34 G02F1/01

    摘要: Apparatus and method for amplitude modulation of laser light by means of an electro-optic waveguide having a grating coupler, the length of the grating being short relative to the coupling length and to the waist of the incident laser beam.

    摘要翻译: 通过具有光栅耦合器的电光波导对激光进行幅度调制的装置和方法,光栅的长度相对于入射激光束的耦合长度和腰部短。

    Mode insensitive waveguide device
    23.
    发明授权
    Mode insensitive waveguide device 失效
    模式无源波导装置

    公开(公告)号:US5212759A

    公开(公告)日:1993-05-18

    申请号:US808705

    申请日:1991-12-16

    IPC分类号: G02B6/122 G02B6/13

    CPC分类号: G02B6/122

    摘要: A waveguide structure includes a substrate, a waveguide film, and an overlay material in contact with the waveguide film. The overlay material may also contact the substrate or the film may be disposed between the overlay and the substrate. The overlay material has a higher refractive index than the waveguide so that the ratio of the effective refractive indexes is substantially constant for all propagating modes supported by the waveguide.

    Achromatic mode-index elements for integrated optical systems
    24.
    发明授权
    Achromatic mode-index elements for integrated optical systems 失效
    用于集成光学系统的消色差模式折射元件

    公开(公告)号:US4979788A

    公开(公告)日:1990-12-25

    申请号:US488164

    申请日:1990-03-05

    IPC分类号: G02B6/122 G02B6/12 G02B6/124

    CPC分类号: G02B6/1245 Y10T428/31725

    摘要: Mode-index optical elements comprise an optical waveguide having a optical overlay of substantially uniform thickness. The contour of the overlay in the plane of the overlay controls the direction of propagation of radiation within the waveguide. According to the invention, mode-index optical elements are optimally achromatized (i.e., rendered as insensitive as possible to radiation wavelength changes) over a desired wavelength rqange by properly selecting the respective thicknesses and bulk refractive indices of the overlay and waveguide components. Specifically, such parameters are chosen so that, for a given waveguide substrate (e.g., quartz) and superstrate (e.g., air), the deviation of the ratio of the respective effective refractive indices of the waveguide element (N.sub.E) and waveguide material (N.sub.WG) from a mean or nominal value is minimized over the desired wavelength range of achromatization.

    摘要翻译: 模式折射率光学元件包括具有基本均匀厚度的光学覆盖层的光波导。 叠层平面内的覆盖层轮廓控制波导内辐射的传播方向。 根据本发明,通过适当地选择覆盖层和波导部件的各自的厚度和体积折射率,模式折射率光学元件在期望的波长范围上被最佳地消色差(即,对于辐射波长变化而言变得不敏感)。 具体地说,选择这样的参数,使得对于给定的波导衬底(例如,石英)和衬底(例如空气),波导元件(NE)和波导材料(NWG)的相应有效折射率的比率的偏差 )从平均值或标称值在所需的消色波长范围内最小化。