Efficient ion-photon coupling is an important component for large-scale ion-trap quantum computing. We propose that arrays of phase Fresnel lenses (PFLs) are a favorable optical coupling technology to match with multi-zone ion traps. Both are scalable technologies based on conventional micro-fabrication techniques. The large numerical apertures (NAs) possible with PFLs can reduce the readout time for ion qubits. PFLs also provide good coherent ion-photon coupling by matching a large fraction of an ion's emission pattern to a single optical propagation mode (TEM $_{00}$ ). To this end we have optically characterized a large numerical aperture phase Fresnel lens (NA=0.64) designed for use at 369.5 nm, the principal fluorescence detection transition for Yb $^+$ ions. A diffraction-limited spot $w_0=350\pm15$ nm ( $1/e^2$ waist) with mode quality $M^2= 1.08\pm0.05$ was measured with this PFL. From this we estimate the minimum expected free space coherent ion-photon coupling to be 0.64\%, which is twice the best previous experimental measurement using a conventional multi-element lens. We also evaluate two techniques for improving the entanglement fidelity between the ion state and photon polarization with large numerical aperture lenses.Efficient ion-photon coupling is an important component for large-scale ion-trap quantum computing. We propose that arrays of phase Fresnel lenses (PFLs) are a favorable optical coupling technology to match with multi-zone ion traps. Both are scalable technologies based on conventional micro-fabrication techniques. The large numerical apertures (NAs) possible with PFLs can reduce the readout time for ion qubits. PFLs also provide good coherent ion-photon coupling by matching a large fraction of an ion's emission pattern to a single optical propagation mode (TEM$_{00}$). To this end we have optically characterized a large numerical aperture phase Fresnel lens (NA=0.64) designed for use at 369.5 nm, the principal fluorescence detection transition for Yb$^+$ ions. A diffraction-limited spot $w_0=350\pm15$ nm ($1/e^2$ waist) with mode quality $M^2= 1.08\pm0.05$ was measured with this PFL. From this we estimate the minimum expected free space coherent ion-photon coupling to be 0.64\%, which is twice the best previous experimental measurement using a conventional multi-element lens. We also evaluate two techniques for improving the entanglement fidelity between the ion state and photon polarization with large numerical aperture lenses.

arXiv:0805.2437Quantum Information and ComputationMar 1, 200913 citations

Coupling ions and photons via an optical cavity

Tracy E. Northup

Bulletin of the American Physical SocietyMar 3, 20140 citations

Large-scale quantum computing with phase Fresnel lenses

Erik W. Streed, B. G. Norton, Justin James Chapman +1 more

Efficient ion-photon coupling is an important component for large-scale ion-trap quantum computing. We propose that phase Fresnel lenses (PFLs) are a favorable optical coupling technology to match with multi-zone ion traps. Both are scalable technologies based on conventional micro-fabrication techniques. Large numerical aperture (NA) PFLs can reduce the readout time for ion qubits and provide good coherent coupling to a single optical mode. From optical characterization of a suitable PFL we predict a coherent coupling efficiency of >0.64%, twice the best experimental efficiency achieved to date. In addition, high NA entanglement fidelity limits can be removed by optical filtering.Efficient ion-photon coupling is an important component for large-scale ion-trap quantum computing. We propose that phase Fresnel lenses (PFLs) are a favorable optical coupling technology to match with multi-zone ion traps. Both are scalable technologies based on conventional micro-fabrication techniques. Large numerical aperture (NA) PFLs can reduce the readout time for ion qubits and provide good coherent coupling to a single optical mode. From optical characterization of a suitable PFL we predict a coherent coupling efficiency of >0.64%, twice the best experimental efficiency achieved to date. In addition, high NA entanglement fidelity limits can be removed by optical filtering.

Jan 1, 20090 citations

A collective ion-photon interface

Leon Karpa, Marko Cetina, Alexei Bylinskii +5 more

Bulletin of the American Physical SocietyJun 14, 20110 citations

Imaging of Trapped Ions with a Microfabricated Optic for Quantum Information Processing

Erik W. Streed, B. G. Norton, Andreas Jechow +2 more

Trapped ions are a leading system for realizing quantum information processing (QIP). Most of the technologies required for implementing large-scale trapped-ion QIP have been demonstrated, with one key exception: a massively parallel ion-photon interconnect. Arrays of microfabricated phase Fresnel lenses (PFL) are a promising interconnect solution that is readily integrated with ion trap arrays for large-scale QIP. Here we show the first imaging of trapped ions with a microfabricated in-vacuum PFL, demonstrating performance suitable for scalable QIP. A single ion fluorescence collection efficiency of 4.2±1.5% was observed. The depth of focus for the imaging system was 19.4±2.4 μm and the field of view was 140±20 μm. Our approach also provides an integrated solution for high-efficiency optical coupling in neutral atom and solid-state QIP architectures.Trapped ions are a leading system for realizing quantum information processing (QIP). Most of the technologies required for implementing large-scale trapped-ion QIP have been demonstrated, with one key exception: a massively parallel ion-photon interconnect. Arrays of microfabricated phase Fresnel lenses (PFL) are a promising interconnect solution that is readily integrated with ion trap arrays for large-scale QIP. Here we show the first imaging of trapped ions with a microfabricated in-vacuum PFL, demonstrating performance suitable for scalable QIP. A single ion fluorescence collection efficiency of 4.2±1.5% was observed. The depth of focus for the imaging system was 19.4±2.4 μm and the field of view was 140±20 μm. Our approach also provides an integrated solution for high-efficiency optical coupling in neutral atom and solid-state QIP architectures.

arXiv:1006.4192Physical Review LettersJan 5, 201188 citations

_{00}

). To this end we have optically characterized a large numerical aperture phase Fresnel lens (NA=0.64) designed for use at 369.5 nm, the principal fluorescence detection transition for Yb

^+

ions. A diffraction-limited spot

w_0=350\pm15

nm (

1/e^2

waist) with mode quality

M^2= 1.08\pm0.05

was measured with this PFL. From this we estimate the minimum expected free space coherent ion-photon coupling to be 0.64\%, which is twice the best previous experimental measurement using a conventional multi-element lens. We also evaluate two techniques for improving the entanglement fidelity between the ion state and photon polarization with large numerical aperture lenses.