Integrated single-beam optical tweezer and planar curved grating for multiple optical traps

This paper presents a single-beam optical tweezer integrated with a planar curved grating for microbeads manipulation. The different curvatures of the surface micromachined planar curved grating are systematically investigated. The planar curved grating was fabricated using Multi-User MEMS Processes (MUMPs) provided by MEMSCAP Inc. The angular separation and the number of diffracted orders were found. Experimental results indicate that the diffraction patterns and the curvature of the planar curved grating reveal a close relationship. As the curvature of planar curved grating increases, the vertical diffraction angle increases, resulting in a strip patterns of the planar curved grating. Moreover, a single-beam optical tweezer has been established. Finally, we demonstrate a technique for creating multiple optical traps from a single laser beam using the developed planar curved grating.