Structured light spots projected by a Dammann grating with high power efficiency and uniformity for optical sorting

Xiaodong Sun, Yuyang Sun, Jing Bu, Siwei Zhu, and X.-C. Yuan

We report a method for microfluidic multiple trapping and continuous sorting of microparticles using an optical potential landscape projected by a Dammann grating, enabling a high power-efficient approach to forming a composite two-dimensional spots array with high uniformity. The Dammann grating is fabricated in a photoresist by optical lithography. It is employed to create an optical lattice for multiple optical trapping and sorting in a mixture of polymer particles (n=1.59) and silica particles (n=1.42) with the same diameters of 3.1μm. In addition to the exponential selectivity by the projected optical landscapes, the proposed microfluidic sorting system has advantages in terms of high power efficiency and high uniformity due to the Dammann grating.

DOI