Enhancement of wavefront measurement sensitivity in a zonal wavefront sensor without curtailing the sensing speed. (16th December 2021)

• Record Type: Journal Article
• Authors: Kumar, Nagendra; Khare, Alika; Boruah, Bosanta R
• Is Part Of: Journal of optics. Volume 24:Number 1(2022)
• Publication Date: 2021-12-16
• Subjects: zonal wavefront sensor -- measurement sensitivity -- liquid crystal spatial light modulator -- binary hologram -- sensing frame rate; Optics -- Periodicals; 535.05
• DOI: 10.1088/2040-8986/ac3890
• Languages: English
• ISSNs: 2040-8978

Abstract

Abstract: In this paper we propose a zonal wavefront sensing scheme that facilitates wavefront measurement with enhanced sensitivity at the standard video rate. We achieve this enhanced sensitivity by implementing a sequential display of binary holograms described over each zone sampling the incident wavefront with the help of a ferroelectric liquid crystal spatial light modulator. By keeping the number of active zones as 24 and using a camera with an imaging frame rate equal to the binary hologram display rate of the spatial light modulator, we are able to reach a sensing frame rate of 60 Hz. In addition to enhanced sensitivity, the proposed scheme facilitates zone-wise tuning of binary holograms and eliminates the possibility of any crosstalk between adjacent zones. We perform a proof-of-principle experiment that validates the proposed zonal wavefront sensing scheme and demonstrates its advantages.