Single Ion Imaging and Fluorescence Collection with a Parabolic Mirror Trap

TL;DR

This paper presents a novel parabolic mirror ion trap that significantly enhances fluorescence collection efficiency for single ions, advancing quantum information processing capabilities.

Contribution

The authors designed and tested a parabolic mirror ion trap that achieves high fluorescence collection efficiency and improved imaging resolution for single ions.

Findings

39% fluorescence collection efficiency from a single ion

Ion image spot size reduced to 2.8 times diffraction limit with deformable mirror

Micromotion identified as a limiting factor for imaging performance

Abstract

Single trapped ion qubit is an excellent candidate for quantum computation and information, with additional ability to coherently couple to single photons. Efficient fluorescence collection is the most challenging part in remote entangled ion qubit state generation. To address this issue, we developed an ion trap combining a reflective parabolic surface with trap electrodes. This parabolic trap design covers a solid angle of 2pi steradians, and allows precise ion placement at the focal point of the parabola. We measured approximately 39% fluorescence collection from a single ion with this mirror, and analyzed the mirror optical performance. We observed single ion image spot size of about 3.4 times diffraction limit, improved to 2.8 times diffraction limit with the help of an external deformable mirror. The micromotion of ion is determined to be the limiting factor, and the result is consistent with theoretical calculation.