Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Letters

Low-noise detection of ultracold atoms

J. M. McGuirk, G. T. Foster, J. B. Fixler, Mark A. Kasevich

Published Mar 15, 2001• 26 citations
Publisher

Abstract

We have demonstrated a new technique for detecting ultracold atoms. A balanced detection technique was used to reduce laser-induced detection noise in conjunction with modulation-transfer spectroscopy to distinguish cold atoms from a thermal cloud. Using this technique, we have achieved signal-to-noise ratios in excess of 2000:1.
DOI
10.1364/ol.26.000364

Related papers

Low Noise Simultaneous Fluorescence Detection of Two Atomic States (PREPRINT)

M. Cashen, Fixler, J. B., Grant W. Biedermann +1 more

We have demonstrated a new technique for fluorescence detection of ultracold atoms. Fluorescence from two spatially separated clouds of ultracold atoms illuminated by a mutual probe laser was imaged onto opposite quadrants of a position-sensitive detector. The populations in the two separated atomic clouds were measured by integrating the quadrant detector photocurrents. Simultaneous detection of the populations of the two atomic clouds was used to reduce noise caused by fluctuations in detection laser amplitude and frequency. Using this technique we observed quantum projection noise limited detection signal-to-noise ratios exceeding 2000:1. To demonstrate the application of our highly Sensitive detection we compared two atomic clocks with interrogation times of only 80 ms to obtain a relative frequency stability of 1x 10(exp -13) Tau (exp -1/2) where TAU is the integration time in seconds.

•Apr 5, 2006•0 citations

Low-noise simultaneous fluorescence detection of two atomic states

Grant W. Biedermann, Xiaojing Wu, Louis Deslauriers +2 more

We demonstrate a new simultaneous normalized detection technique for fluorescence detection of ultracold atoms in a superposition of ground-state hyperfine levels. Using this technique we observe atom shot-noise limited detection signal-to-noise ratios in excess of 7800:1 per shot and 14400:1 in 1 s.

Optics Letters•Jan 27, 2009•40 citations

Optical detection of cold atoms without spontaneous emission

V. Savalli, G. Horváth, P. D. Featonby +4 more

We have demonstrated nondestructive detection of cold atoms with a probe laser by a frequency-modulation spectroscopy technique. We were able to tune the probe laser and its sidebands far from atomic resonance to reduce the spontaneous emission to less than 0.2 photon per atom during detection.

Optics Letters•Nov 15, 1999•20 citations

Optimal strategies for low-noise detection of atoms using resonant frequency modulation spectroscopy in cold-atom interferometers

Ryan Thomas, Samuel Legge, Simon A. Haine +1 more

Resonant frequency modulation spectroscopy has been previously used as a highly sensitive method for measuring the output of cold atom interferometers. Using a detailed model that accounts for optical saturation, laser intensities and atomic densities that vary spatially, and radiation pressure on the atoms, we theoretically investigate under what parameter regimes the optimum signal-to-noise ratio is found under experimentally realistic conditions. We compare this technique to the standard method of fluorescence imaging and find that it outperforms fluorescence imaging for compact interferometers using condensed atomic sources or where the photon collection efficiency is limited. However, we find that fluorescence imaging is likely to be the preferred method when using squeezed atomic sources due to limited atom number.

arXiv:2408.06575•Physical Review A•Dec 10, 2024•0 citations

Limit to Minimally Destructive Optical Detection of Atoms

J. J. Hope, J. D. Close

All optical techniques used to probe the properties of Bose-Einstein condensates have been based on dispersion and absorption that can be described by a two-level atom. Both phenomena lead to spontaneous emission that is destructive at the low energies involved with ultracold atomic systems. Recently, both were shown to lead to the same limit to the signal to noise ratio for a given destruction. We develop a new method for calculating the phase shift of a laser beam and show that no single-pass optical technique using classical light and a three-level atom can exceed this limit. This puts significant restrictions on potential nondestructive measurement schemes.

arXiv:quant-ph/0308153•Physical Review Letters•Oct 25, 2004•36 citations

A Clearer View of Cold Atoms

The sharpening of atomic energy levels with decreasing temperature is the motivation for using atoms cooled to just a fraction above absolute zero as the detection medium for metrological applications. Ultracold atom “fountains” already have been used in atomic clocks and in gravimeters and gravity gradiometers. However, the cooling process provides a thermal cloud of warmer atoms that surround the cold-atom core, and as detection of the atoms usually relies on monitoring fluorescence or absorption transitions between energy levels, these thermal atoms broaden the spectra and reduce sensitivity.

Science•Apr 6, 2001•0 citations
We have demonstrated a new technique for fluorescence detection of ultracold atoms. Fluorescence from two spatially separated clouds of ultracold atoms illuminated by a mutual probe laser was imaged onto opposite quadrants of a position-sensitive detector. The populations in the two separated atomic clouds were measured by integrating the quadrant detector photocurrents. Simultaneous detection of the populations of the two atomic clouds was used to reduce noise caused by fluctuations in detection laser amplitude and frequency. Using this technique we observed quantum projection noise limited detection signal-to-noise ratios exceeding 2000:1. To demonstrate the application of our highly Sensitive detection we compared two atomic clocks with interrogation times of only 80 ms to obtain a relative frequency stability of 1x 10(exp -13) Tau (exp -1/2) where TAU is the integration time in seconds.
Resonant frequency modulation spectroscopy has been previously used as a highly sensitive method for measuring the output of cold atom interferometers. Using a detailed model that accounts for optical saturation, laser intensities and atomic densities that vary spatially, and radiation pressure on the atoms, we theoretically investigate under what parameter regimes the optimum signal-to-noise ratio is found under experimentally realistic conditions. We compare this technique to the standard method of fluorescence imaging and find that it outperforms fluorescence imaging for compact interferometers using condensed atomic sources or where the photon collection efficiency is limited. However, we find that fluorescence imaging is likely to be the preferred method when using squeezed atomic sources due to limited atom number.
All optical techniques used to probe the properties of Bose-Einstein condensates have been based on dispersion and absorption that can be described by a two-level atom. Both phenomena lead to spontaneous emission that is destructive at the low energies involved with ultracold atomic systems. Recently, both were shown to lead to the same limit to the signal to noise ratio for a given destruction. We develop a new method for calculating the phase shift of a laser beam and show that no single-pass optical technique using classical light and a three-level atom can exceed this limit. This puts significant restrictions on potential nondestructive measurement schemes.
The sharpening of atomic energy levels with decreasing temperature is the motivation for using atoms cooled to just a fraction above absolute zero as the detection medium for metrological applications. Ultracold atom “fountains” already have been used in atomic clocks and in gravimeters and gravity gradiometers. However, the cooling process provides a thermal cloud of warmer atoms that surround the cold-atom core, and as detection of the atoms usually relies on monitoring fluorescence or absorption transitions between energy levels, these thermal atoms broaden the spectra and reduce sensitivity.