Impact of the rolling shutter effect in optical phase measurements using spatial carrier

Abstract

The impact of the rolling shutter effect in interferometry using the spatial carrier method is presented. A spatial carrier method is of interest as it avoids moveable devices inside the interferometer, thus allowing the design of low-cost and portable optical systems. An out-of-plane digital holographic interferometer is used to analyze the retrieved optical phase acquired by a camera sensor which can be hardware switched between rolling and global shutter mode. Under well-controlled and repeatable deformations, a series of image holograms were recorded. Optical phase comparison is performed for both shutter modes to analyze the presence or absence of the rolling shutter effect (RSE) in the spatial carrier. The optical phase study involves the Fourier spectrum, where this spatial carrier could be explored in a bi-dimensional form. Results show a significant distortion of the spatial carrier at the Fourier space, close to the edges of the optical aperture image, indicating a phase error that can be reduced using a reduced section of the aperture.