QGM_Post | UMQT

Comparison of deconvolution techniques

Sun, 16 Jul 2023 00:00:00 +0000

Motivation

To understand the limits of single-atom imaging compare the effectiveness of three different deconvolution techniques that are commonly used to process the fluorescence images. We use simulated images to determine the fidelity of detecting single atoms in an optical lattice in the presence of noise, inhomogeneous fluorescence, for parameter regimes relevant to other quantum-gas microscope experiments.

Example for growing excitation modes

A wave packet, which is initially centred at zero momentum, quickly spreads over the complete Brillouin zone due to interactions and periodic driving. Those instabilities make quantum simulation experiments challenging.

Hyperlink

New J. Phys. 25, 083036 (2023).

Experimental setup

Abstract

Quantum-gas microscopes are used to study ultracold atoms in optical lattices at the singleparticle level. In these systems atoms are localised on lattice sites with separations close to or below the diffraction limit. To determine the lattice occupation with high fidelity, a deconvolution of the images is often required. We compare three different techniques, a local iterative deconvolution algorithm, Wiener deconvolution and the Lucy-Richardson algorithm, using simulated microscope images. We investigate how the reconstruction fidelity scales with varying signal-to-noise ratio, lattice filling fraction, varying fluorescence levels per atom, and imaging resolution. The results of this study identify the limits of singe-atom detection and provide quantitative fidelities which are applicable for different atomic species and quantum-gas microscope setups.

Accurate holographic light potentials using pixel crosstalk modelling

Fri, 24 Feb 2023 00:00:00 +0000

Hyperlink

Scientific Reports 13, 3252 (2023).

Abstract

Sub-Doppler laser cooling of 40K

Wed, 12 Apr 2017 00:00:00 +0000

Abstract

Gray molasses is a powerful tool for sub-Doppler laser cooling of atoms to low temperatures. For alkaline atoms, this technique is commonly implemented with cooling lasers which are blue-detuned from either the D1 or D2 line. Here we show that efficient gray molasses can be implemented on the D2 line of 40K with red-detuned lasers. We obtained temperatures of $48(2),\mu {\rm{K}}$, which enables direct loading of $9.2(3)\times {10}^{6}$ atoms from a magneto-optical trap into an optical dipole trap. We support our findings by a one-dimensional model and three-dimensional numerical simulations of the optical Bloch equations which qualitatively reproduce the experimentally observed cooling effects.

Hyperlink

J. Phys. B: At. Mol. Opt. Phys. 50 095002 (2017).