Details

Autor(en) / Beteiligte

• Chen, Dihan
• Gu, Songyun
• Chen, Shih-Chi

Titel

Study of Optical Modulation based on Binary Masks with Finite Pixels

Ist Teil von

• Optics and lasers in engineering, 2021-07, Vol.142, p.106604, Article 106604

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• •We present a new model to predict and analyze errors associated with wavefront modulation based on digital holography and binary masks, e.g., digital micromirror devices or ferroelectric liquid crystal-based spatial light modulators, which has been a widely-adopted method in the optical engineering community.•To demonstrate the accuracy and practical use of the model, we present three case studies, including (1) beam shaping, (2) 3D random-access scanning, and (3) multi-focus generation based on binary masks.•The results show the analytical model can precisely predict the wavefront distortion, power efficiency, position accuracy, and intensity uniformity for multi-focus generation as a function of binary mask parameters including pixel size, pixel gentry, fill factor, and aperture.•As digital systems are highly repeatable, the predicted errors, e.g., position errors, can be compensated by adding appropriate phase to the designed holograms. The model and the simulation results will be a useful tool for optical engineers to select appropriate binary devices and optimization algorithms for specific engineering applications, e.g., nanofabrication or nonlinear microscopy. Binary holography has been applied with fast switching digital masks, e.g., digital micromirror device (DMD), to modulate light in recent years for a wide range of optical and scientific applications, such as trapping of cold atoms and 3D random-access two-photon fluorescence microscopy. However, the binarized modulation errors associated with the effect of discrete sampling, finite pixels, and intrinsic noises of algorithms have yet to be systematically investigated. In this paper, we present the development of an analytical model for a general binary mask with finite pixels. The model has established a deterministic link between the quality of the reconstructed wavefront to important parameters of the binary mask, including pixel size, pixel geometry, fill factor, and aperture. Based on the model, three case studies are presented, including (1) beam shaping, (2) 3D random-access scanning, and (3) multi-focus generation based on binary masks. The results show the model can precisely predict the wavefront distortion, power efficiency, position accuracy, and intensity uniformity for multi-focus generation as a function of binary mask parameters. As digital systems are highly repeatable, the predicted errors, e.g., position errors, can be compensated by adding appropriate phase to the designed holograms. The model and the simulation results may provide useful guidance to select appropriate binary devices and optimization algorithms for specific optical engineering applications, e.g., nanofabrication or nonlinear microscopy.