针对水下光通信受湍流、生物活动等影响引起链路失准，或通信距离改变导致接收光强变化较大的问题，结合直流偏置正交频分复用光信号的特点，提出了一种自适应光强探测电路。该电路通过自动增益控制技术调整对接收信号的放大倍数，输出稳定的电信号。首先对自适应光强探测电路的相关参数进行理论分析和仿真验证，然后设计研制该电路并进行空气信道和水下信道的实验测试。结果表明，该电路能够实现对不同强度光信号的自适应调节，输出电信号峰峰值基本稳定在600 mV左右，波动范围为-3.3%~3.3%。

A numerical simulation is performed to study the far-field diffraction properties of planar diamond waveguides. The far-field intensity distributions of a planar air waveguide and a diamond waveguide with different distances are given by numerical calculations. In the experiment, the diffraction patterns on the screen with different distances are recorded using a He-Ne laser as the light source, wherein the laser beam is coupled with and propagates in the diamond waveguide. The simulation results are found to be consistent with the experimental ones.

基于Jones矩阵理论和液晶弹性自由能理论，分析计算了扭曲向列型液晶空间光调制器(TN－LCSLM)的复振幅调制特性．以显示一维矩形光栅为例，详细计算了不同输入输出偏振器配置下的一级衍射效率．数值计算结果和分析表明，在加输出偏振器和不加输出偏振器两种情况下都存在一个具有最大一级衍射效率的取向配置．