Wobulation using a tunable electrowetting prism applied to structured illumination microscopy

Abstract

Sub-pixel shifting technologies are attractive for enhancing the resolution of cameras and projectors. Conventional techniques, such as wobulation and pixel shift, rely on mechanical moving parts or cumbersome optical systems. As a solution, we demonstrate “electrowetting wobulation,” in which a tunable electrowetting prism is used to laterally shift a projected image. This technique overcomes challenges of other pixel shifting techniques, as the electrowetting prism is transmissive, can achieve high framerates, and has no mechanical moving parts. We apply electrowetting wobulation to an optical sectioning structured illumination microscope and demonstrate lateral shifting of a structured pattern while maintaining optical sectioning, which requires high quality images. We characterize the optical sectioning strength across multiple spatial frequencies, as well as demonstrate enhanced sectioning in an autofluorescent pollen grain, and find electrowetting wobulation is a promising technology to improve the resolution of conventional imaging systems.