根据以下的平板光波导折射率数据：
（1）作出不同波导芯层厚度 ( )对应的 模式与 模式的色散图；
（2）给出满足单模与双模传输的波导厚度范围；
（3）确定包层所需的最小厚度 与 的值。(According to the following refractive index data of planar optical waveguide:

(1) The dispersion diagrams of modes and modes corresponding to different thickness of waveguide core layer () are made;

(2) The range of waveguide thickness for single mode and dual-mode transmission is given;

(3) Determine the minimum thickness and value required for cladding.)