阵列光镊衍射元件的算法设计

Algorithm for Diffractive Optical Element of Array Optical Tweezers

作为光镊技术近年来最重要的发展之一,二维阵列光镊在纳米制造和生物芯片制作中具有广泛的应用前景。衍射光学元件是构成阵列光镊的关键器件之一,而Gerchberg-Saxton(G-S)算法是设计相位型衍射光学元件的一种常用方法。实现了伪随机编码的G-S算法,并将计算得到的相位分布图输入到液晶空间光调制器上,在透镜的后焦面上得到阵列分布的光点,提出并实验验证了通过振幅调制能够有效减少远场衍射的背景噪声,为将来设计阵列光镊衍射元件提供了可能。

As one of the most important techniques in optical tweezers, two-dimensional array optical tweezers have the widespread applications in nanofabrication and biochip manufacturing. Diffractive optical element is the key device to design array optical tweezers. Combined theoretical simulations using pseudo-random phases encoding through Gerchberg-Saxton （G-S） algorithm with experimental measurements, we find that obvious background noise appears when the regular output distribution is array points. A double amplitude filter is adopted to effectively suppress the background noise and impove the quality of diffraction images. These findings are helpful for designing array optical tweezers in the near future.