Volume holograms with linear diffraction efficiency relation by (3+1)D printing

TL;DR

This paper introduces a novel (3+1)D printing method for fabricating volume holograms with a linear diffraction efficiency relation, overcoming the traditional inverse square law limit through independent voxel control and digital filtering.

Contribution

The paper presents the first experimental demonstration of distributed volume holograms with a linear diffraction efficiency relation, surpassing the 1/M^2 limit of conventional methods.

Findings

Demonstrated linear diffraction efficiency relation with 50 multiplexed holograms.

Used (3+1)D printing to independently control voxel refractive index.

Overcame the traditional 1/M^2 diffraction efficiency limit.

Abstract

We demonstrate the fabrication of volume holograms using 2-photon polymerization with dynamic control of light exposure. We refer to our method as (3+1)D printing. Volume holograms that are recorded by interfering reference and signal beams have a diffraction efficiency relation that is inversely proportional with the square of the number of superimposed holograms. By using (3+1)D printing for fabrication, the refractive index of each voxel is created independently and thus by, digitally filtering the undesired interference terms, the diffraction efficiency is now inversely proportional to the number of multiplexed gratings. We experimentally demonstrated this linear dependence by recording M=50 volume gratings. To the best of our knowledge, this is the first experimental demonstration of distributed volume holograms that overcome the 1/M^2 limit.