Dynamic complex opto-magnetic holography

TL;DR

This paper introduces a novel method for real-time, dynamic hologram recording using ultrafast opto-magnetic materials, enabling efficient, high-quality 3D holography without extensive computational or memory resources.

Contribution

It presents a new approach combining hardware computation and opto-magnetic recording to generate dynamic holograms without Fourier transforms, reducing memory and computational demands.

Findings

Successful experimental demonstration of dynamic hologram recording in ferrimagnetic films.

Achieved complex modulation with suppression of unwanted diffraction orders.

Enabled real-time, high-resolution 3D holography with minimal computational resources.

Abstract

Computer-generated holograms with their animated, three-dimensional appearance have long appealed to our imagination as the path towards truly immersive displays with bi-directional natural parallax. Impressive progress in updateable 3-D imagery has been achieved with liquid crystal modulators and high-resolution, but quasi-static holograms are being recorded in photosensitive materials. However, the memory requirements and computational loads of real-time, large-area holography will be hard to tackle for several decades to come with the current paradigm based on a matrix calculations and bit-plane writing. Here, we experimentally demonstrate a conceptually novel, holistic approach to serial computation and repeatable writing of computer-generated dynamic holograms without Fourier transform, using minimal amounts of computer memory. We use the ultrafast opto-magnetic recording of holographic patterns in a ferrimagnetic film with femtosecond laser pulses, driven by on-the-fly hardware computation of a single holographic point. The intensity-threshold nature of the magnetic medium allows sub-diffraction-limited, point-by-point toggling of arbitrarily localized magnetic spots on the sample, according to the proposed circular detour-phase encoding, providing complex modulation and symmetrical suppression of upper diffractive orders and conjugated terms in holographically reconstructed 3-D images.