We propose a quantum algorithm that simulates the propagation of a light field through a weakly inhomogeneous medium. In the paraxial approximation, the wave equation in an inhomogeneous material takes the form of the Schrödinger equation with a time-dependent Hamiltonian. This reduction is used to simulate wave optical dynamics on a quantum computer. Beam propagator operators for a short propagation distance are constructed using an efficient and flexible block-encoding that enables the simulation of various optical setups. The algorithm is showcased by simulating the propagation of a one-dimensional Gaussian beam through a lens of finite thickness, and the resulting spherical aberration is demonstrated.
Atom lens generated by a laser standing wave can be used to focus an atomic beam to nanometer dimensions. Aberrations exist in atom lens owing to the influence of velocity spread, beam spread, wave nature of atoms and so on. Two theoretical models were built to describe atom lens. Spherical aberration, chromatic aberration and the aberration caused by angular spread were analyzed with semi-classical model, and diffractive aberration was analyzed using quantum model. Simulation results show that aberration originates mainly from beam spread, and diffractive aberration is larger than spherical aberration and chromatic aberration. Three solutions of optimization of experimental parameters, adding beam mask and using etching technologies for improving atom lithography quality are presented.
The focusing of an atomic beam using near-resonant laser light is considered. Path-integral techniques are employed to transform the problem into a standard diffraction integral. This approach is general and allows us to deal with thick laser lenses. Starting from the basic form of the potential energy for an atom in a laser beam, we derive the propagation kernel for the atomic wave function for the particular case of a TEM01*, or doughnut, mode laser beam. Both the full three-dimensional propagation kernel and its paraxial approximation are discussed. We show that the paraxial case can be obtained from the three-dimensional case by a stationary-phase approximation of the propagation equation. Numerical results for the focusing of a Gaussian atomic beam are presented. These results show that spot diameters on the order of 20 Å are obtainable for many reasonable choices of laser and atomic beam parameters and that for most of these cases the thin-lens approximation is not valid. The effects of the lowest-order aberrations are also briefly discussed. Spherical aberration is found to contribute significantly to the focal spot diameter, at least for the doughnut mode laser beam considered here.
A new wavefront sensing framework based on the interference of counter-accelerating Airy beams is presented. An engineered cubic phase function transforms a single Gaussian beam into two coherent Airy beams with opposite transverse accelerations, which self-recombine during free-space propagation to form an interference pattern encoding the aberrated incident wavefront. Numerical simulations demonstrate accurate recovery of the aberrated exit-pupil phase across the aberration sets considered, with a root-mean-square phase reconstruction error below
10−6rad for the aberration set shown and consistently low errors for the other sets, while maintaining accurate recovery in the presence of measurement noise. The approach eliminates collection optics and enables a compact wavefront-sensing architecture for applications where conventional interferometric systems are difficult to implement, including electron-optical systems, augmented and virtual reality systems.