Elements of Quantum Optics

Pierre Meystre, Murray Sargent

Pierre Meystre, Murray SargentIII

Pierre Meystre, Murray Sargent

A. L. Young, Shanalyn A. Kemme, J. R. Wendt +2 more

The viability of neutral atom based quantum computers is dependent upon scalability to large numbers of qubits. Diffractive optical elements (DOEs) offer the possibility to scale up to many qubit systems by enabling the manipulation of light to collect signal or deliver a tailored spatial trapping pattern. DOEs have an advantage over refractive microoptics since they do not have measurable surface sag, making significantly larger numerical apertures (NA) accessible with a smaller optical component. The smaller physical size of a DOE allows the micro-lenses to be placed in vacuum with the atoms, reducing aberration effects that would otherwise be introduced by the cell walls of the vacuum chamber. The larger collection angle accessible with DOEs enable faster quantum computation speeds. We have designed a set of DOEs for collecting the 852 nm fluorescence from the D2 transition in trapped cesium atoms, and compare these DOEs to several commercially available refractive micro-lenses. The largest DOE is able to collect over 20% of the atom’s radiating sphere whereas the refractive micro-optic is able to collect just 8% of the atom’s radiating sphere.

Shanalyn A. Kemme

We developed techniques to design higher efficiency diffractive optical elements (DOEs) with large numerical apertures (NA) for quantum computing and quantum information processing.Large NA optics encompass large solid angles and thus have high collection efficiencies.Qubits in ion trap architectures are commonly addressed and read by lasers 1 .Large-scale ion-trap quantum computing 2 will therefore require highly parallel optical interconnects.Qubit readout in these systems requires detecting fluorescence from the nearly isotropic radiation pattern of single ions, so efficient readout requires optical interconnects with high numerical aperture.Diffractive optical element fabrication is relatively mature and utilizes lithography to produce arrays compatible with large-scale ion-trap quantum computer architectures.The primary challenge of DOEs is the loss associated with diffraction efficiency.This is due to requirements for large deflection angles, which leads to extremely small feature sizes in the outer zone of the DOE.If the period of the diffractive is between  (the free space wavelength) and 10 the element functions in the vector regime.DOEs in this regime, particularly between 1.5 and 4 have significant coupling to unwanted diffractive orders, reducing the performance of the lens.Furthermore, the optimal depth of the zones with periods in the vector regime differs from the overall depth of the DOE.We will present results indicating the unique behaviors around the 1.5 and 4 periods and methods to improve the DOE performance.

Liron Stern, Douglas G. Bopp, Susan A. Schima +2 more

The efficient light-matter interaction and discrete level structure of atomic vapors made possible numerous seminal scientific achievements including time-keeping, extreme non-linear interactions, and strong coupling to electric and magnetic fields in quantum sensors. As such, atomic systems can be regarded as a highly resourceful quantum material platform. Recently, the field of thin optical elements with miniscule features has been extensively studied demonstrating an unprecedented ability to control photonic degrees of freedom. Hybridization of atoms with such thin optical devices may offer a material system enhancing the functionality of traditional vapor cells. Here, we demonstrate chip-scale, quantum diffractive optical elements which map atomic states to the spatial distribution of diffracted light. Two foundational diffractive elements, lamellar gratings and Fresnel lenses, are hybridized with atomic vapors demonstrating exceptionally strong frequency-dependent, non-linear and magneto-optic behaviors. Providing the design tools for chip-scale atomic diffractive optical elements develops a path for compact thin quantum-optical elements.