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

Ion-photon networks for scalable quantum computing

Susan Clark, David Hayes, David Hucul +6 more

Bulletin of the American Physical SocietyJun 14, 20110 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

Optical Characterization Of A Phase Fresnel Lens For Trapped Ion Quantum Computing

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

To efficiently collect light from ions in a trapped ion quantum computer, a lens with a high numerical aperture is advantageous. Using phase Fresnel lenses with large working distances and high numerical apertures, we can couple a large fraction of the fluorescence from an ion into a single optical propagation mode (TEM00). We have optically profiled a phase Fresnel lens with a numerical aperture of 0.64 and a focal length of 3 mm. A 350ᱵ nm beam waist and a beam quality M2 of 1.08ᰮ05 was measured near the diffraction limit.To efficiently collect light from ions in a trapped ion quantum computer, a lens with a high numerical aperture is advantageous. Using phase Fresnel lenses with large working distances and high numerical apertures, we can couple a large fraction of the fluorescence from an ion into a single optical propagation mode (TEM00). We have optically profiled a phase Fresnel lens with a numerical aperture of 0.64 and a focal length of 3 mm. A 350ᱵ nm beam waist and a beam quality M2 of 1.08ᰮ05 was measured near the diffraction limit.

Jan 1, 20090 citations

Time- and frequency-resolved quantum optics for large-scale quantum computing

Olivier Pfister

SPIE NewsroomFeb 25, 20160 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.