Comparative simulations of Fresnel holography methods for atomic waveguides

Abstract

We have simulated the optical properties of micro-fabricated Fresnel zone plates (FZPs) as an alternative to spatial light modulators for producing non-trivial light potentials to trap atoms within a lensless Fresnel arrangement. We show that binary (1 bit) FZPs with wavelength (1 μm) spatial resolution consistently outperform kinoforms of spatial and phase resolution comparable to commercial SLMs in root mean square error comparisons, with FZP kinoforms demonstrating increasing improvement for complex target intensity distributions. Moreover, as sub-wavelength resolution microfabrication is possible, FZPs provide an exciting possibility for the creation of static cold-atom trapping potentials useful to atomtronics, interferometry, and the study of fundamental physics.

Optical characterisation of micro-fabricated Fresnel zone plates for atomic waveguides

“…A simple quantitative measure of trap 'goodness' uses the root mean squared (RMS) error between an ideal trap and the observed trap. This is an established method used in SLM holography as an optimisation parameter for design algorithms [47][48][49][50] or to compare design methods [30]. We calculate E the RMS error of the top 10% of the potential, relative to total potential depth, and this is shown in Table 1.…”

“…They are particularly suitable for compact quantum technologies due to their simplicity, planar form factor, and the potential for low cost mass-production. In this paper, we present the optical testing of a variety of Fresnel zone plate geometries -yielding high-intensity rings, guides and beamsplitters -that were manufactured following our theoretical proposal [30].…”

“…A selection of 24 patterns, with 2 mm separation and 2 mm diameter, were etched with regularly spaced 1 × 1 µm 2 'pixels' onto a 18 × 26 × 3 mm 3 fused silica substrate by Holo/Or [34]. The binary patterns have two distinct heights resulting in a modulation of the propagated light phase by π between zones of the FZP [30]. For shorter optical wavelengths, and 10 nm resolution over cm 2 areas, electron-beam lithography could be used for FZP fabrication [35].…”

Focus on atomtronics-enabled quantum technologies

“…• Comparative simulations of Fresnel holography methods for atomic waveguides, Henderson et al [33].…”

The UK National Quantum Technologies Hub in sensors and metrology (Keynote Paper)

“…The Hub aims to overcome technological challenges in cold atom rotation sensors by developing new pulse techniques 19 and use them to demonstrate a miniature cold atom gyroscope; in parallel, we shall introduce guiding schemes that allow the apparatus to be shrunk massively. As no clear optimum solution is available, we will start from our pioneering suggestions in magnetic 20,21 and diffractive optical 22 atom guides and our developments driving guided rotation sensors in the EU project MatterWave: we will develop alternative schemes such as microwave based waveguides for rotation sensing 23 . The selection process of a final technology will be aided by developing an industry-compatible systems simulation based on our world-leading optical interferometry simulation programme Finesse (http://www.gwoptics.org/finesse/).…”