针对光镊系统本身噪声对测量精度的影响, 提出了一种光镊系统随机漂移误差的有效补偿方法。首先, 介绍了时间序列分析法和卡尔曼滤波技术, 基于时间序列分析法建立了光镊的随机漂移误差模型; 然后, 用基于时间序列模型的卡尔曼滤波方法来减小该漂移误差。采用提出的方法对光镊设备实测数据的误差进行了补偿, 结果表明: 数据的误差方差由补偿前的188.90 nm2减小为8.41 nm2。计算补偿前后的艾伦方差可知, 系统在平均时间为1 s时可使最小位移误差从 0.7 nm降低到0.1 nm。得到的结果显示: 提出的滤波方法有效地抑制了光镊系统的漂移误差,将其用于双光镊对准可提高捕获光和探测光的对准精度, 进而提高光镊系统的性能指标。

In consideration of the effect of noise in an optical tweezer on its measuring accuracy, an effective compensation method for the random drift error of the optical tweezer was proposed. Firstly, the time series analysis and Kalman filter methods were introduced. Then the random drift error of the tweezer was modeled by time series analysis method and the Kalman filter was proposed to decrease this drift error. The testing error from an optical tweezer test setup was compensated. The compensating result shows that the error variance is reduced from 188.90 nm2 to 8.41 nm2. The data analysis with the Allan variance method demonstrates that the minimum error is reduced from 0.7 nm to 0.1 nm for an averaging time of 1 s. The experiment shows that the method mentioned above can effectively compensate the random drift error of the optical tweezer. It can be used in aligning the double optical tweezers and can improve the accuracy of initial alignment for a capturing light and a detecting light in the double optical tweezer and can enhance the equipment performance.