采用图形处理器加速的部分相干光实时生成方法

Partially Coherent Beam Real-Time Generation Method Accelerated by Graphic Processing Unit

介绍了采用液晶空间光调制器产生部分相干光的基本理论和方法;用分离变量的方式对算法进行了并行优化,对部分相干光生成线程进行了并行序列优化并测试了生成速度;设计了双孔干涉实验检测本方法所产生的部分相干光相干长度的准确性.实验结果表明:针对256×256像素的液晶空间光调制器,生成相干长度为0.15mm、0.9mm以及1.5mm的相位屏,图形处理器所用时间分别为0.9ms、1.75ms以及2.4ms,相比于采用中央处理器所用的计算时间16.5ms、37.8ms以及52.4ms,效率提升明显;考虑中央处理器读取、发送数据及液晶响应的时间,采用图形处理器并行加速的部分相干光实时生成方法的频率可达312Hz.实验生成相干长度为0.15mm和1.5mm的部分相干光束,光束相干度均方根误差分别为0.022 011和0.020 883,峰谷值分别为0.0743 25和0.072 998.

The theory and method for generating partially coherent beam based on liquid-crystal spatial light modulator were given.The method was optimized by using partition convolution,the generation of partially coherent beam was parallel sequential optimizied and the generation speed was tested.The coherence width accuracy of partially coherent beam based on double hole interference was detected.Experimental results show that,to a spatial light modulator with a resolution of 256×256,the total time of generating the random phase maps with coherence widths of 0.15 mm,0.9mm and 1.5mm by graphic processing unit are 0.9ms,1.75 ms and 2.4ms,respectively,which are 16.5ms,37.8ms and 52.4ms by using central processing unit.Considering the reading,sending and response time of the liquid-crystal spatial light modulator by central processing unit,the real-time partially coherent beam generation frequency is up to 312 Hz,which is accelerated by graphic processing unit.For generating apartially coherent laser beam with coherence widths are 0.15 mm and 1.5 mm respectively,the the root-meansquare error are 0.021 306 and 0.020 883,the peak-to-valley are 0.073 576 and 0.072 998.