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

Frontiers in Optics

Two-Photon Spectroscopy in Rb for an Optical Frequency Standard

Gretchen R. Phelps, N. Lemke, Chris Erickson, John H. Burke

Published Jan 1, 2015• 1 citation
Publisher

Abstract

We report on the development of an atomic clock for both ground and space applications, based upon the two-photon transition in Rb. Off-the-shelf components allow for a simple architecture that supports 7 × 10 − 13 / τ at 1 second.
DOI
10.1364/ls.2015.lth4i.5

Related papers

A Compact Optical Rubidium Atomic Frequency Standard

Gretchen R. Phelps, N. Lemke, Kyle W. Martin +2 more

Precision navigation and timing is an important focus in the Air Force Research Laboratory's experimental efforts. The development and testing of an optical frequency standard is suitable for an array of both terrestrial and space based applications. An optical atomic clock based upon a two-photon transition at 778 nm in rubidium, is an ideal candidate to meet the requirements of Global Satellite Navigation System (GNSS), while being a viable option for other applications. Here we demonstrate that a simple architecture, using off-the-shelf components and an external cavity diode laser system that is confined to less than 3 ft2 of breadboard, exhibits a frequency instability of 7 x 10-13/??, for times less than 100 seconds.

Proceedings of the ... annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting/Proceedings of a meeting - Precise Time and Time Interval (PTTI) Systems and Applications Meeting•Feb 26, 2016•3 citations

Compact Optical Atomic Clock Based on a Two-Photon Transition in Rubidium

Kyle W. Martin, Gretchen R. Phelps, N. Lemke +7 more

Optical frequency standards surpass their microwave counterparts in both stability and accuracy, yet they are often bulky, power-hungry, and unable to operate outside of a well-controlled laboratory environment. Leveraging a two-photon transition in ${}^{87}$Rb vapor and recent advances in fiber frequency combs, the authors build an optical clock to beat the current portable standards, with an architecture that can be made compact and low-power. These results point the way to a real-world optical frequency standard of even higher stability, for applications such as satellite navigation.

arXiv:1903.11231•Physical Review Applied•Jan 18, 2018•171 citations

Compact Optical Clock with 5×10 −13 Instability at 1 s

Gretchen R. Phelps, N. Lemke, Christopher Erickson +2 more

We present a compact optical atomic clock design based on a two-photon transition at 778 nm in rubidium that is capable of a frequency instability of 5×10−13 at 1 s. The simple architecture occupies less than 30 L volume and currently uses commercial off-the-shelf components making this system an attractive, appealing, and competitive candidate to meet GPS-III spacecraft frequency stability requirements. Copyright © 2018 Institute of Navigation.

NAVIGATION Journal of the Institute of Navigation•Mar 1, 2018•19 citations

Progress Towards the Development of a Portable All-optical Atomic Clock Based on a Two-photon Transition in Warm Atomic Vapor

S. Jana, B. K. Sahoo, Arijit Sharma

Optical clocks represent the hallmark of precise timekeeping. The most precise atomic clocks are laboratory-based ones that utilize transitions in the microwave/optical domain of neutral atoms or trapped ions. These clocks define an international time scales, confirm the consistency of physical constants and stimulate the search for new physics outside the Standard Model. The other area is the regime of portable atomic clocks based on warm atomic vapor, which is small, power-efficient and deployable in the field with a variety of civilian applications, including sensing, communication and navigation. Two-photon resonance and optical transition based field deployable clocks present a viable alternative that may outperform current commercial chip scale clocks by at least a factor of 10 in terms of both long-term and short-term stability. For portable clocks, two-photon transitions in alkaline earth metals are of special interest. One of the systematic inaccuracies in the optical reference is eliminated by using counter-propagating laser beams to create Doppler-free spectroscopy. At IIT Tirupati, we are engaged in developing the next generation of atomic vapor based portable frequency standard using two-photon transition in Rubidium (Rb) for atomic sensing and quantum positioning applications. This article discusses the physics behind the two-photon transition in Rubidium atoms suitable for a clock reference. Briefly, it discusses the experimental methodology for realizing an optical clock using warm rubidium vapor.

URSI Regional Conference on Radio Science (URSI-RCRS)•Dec 1, 2022•1 citation

Dichroic Two-Photon Rubidium Frequency Standard

Christopher Perrella, P. S. Light, James D. Anstie +3 more

Frequency standards find wide use in navigation and timing for industry, civilian, and defense applications. Unfortunately, the very best frequency standards are bulky, power-hungry, and confined to well-controlled laboratory environments. Here the authors aim to deliver a compact, high-performance standard, the key challenge being the need to produce a strong, narrow atomic transition. They produce a superstrong signal by driving a two-photon transition in ${}^{87}$Rb vapor that exploits a fortuitous third atomic level to greatly enhance the effective strength of the atom-light interaction, allowing short-term clock performance comparable to today's best commercial frequency standards.

Physical Review Applied•Nov 27, 2019•41 citations

A Compact Optical Atomic Clock Based on a Two-Photon Transition in Rubidium

Benjamin Stuhl, Kyle W. Martin, Gretchen R. Phelps +1 more

Bulletin of the American Physical Society•Jun 1, 2018•1 citation
Precision navigation and timing is an important focus in the Air Force Research Laboratory's experimental efforts. The development and testing of an optical frequency standard is suitable for an array of both terrestrial and space based applications. An optical atomic clock based upon a two-photon transition at 778 nm in rubidium, is an ideal candidate to meet the requirements of Global Satellite Navigation System (GNSS), while being a viable option for other applications. Here we demonstrate that a simple architecture, using off-the-shelf components and an external cavity diode laser system that is confined to less than 3 ft2 of breadboard, exhibits a frequency instability of 7 x 10-13/??, for times less than 100 seconds.
Optical frequency standards surpass their microwave counterparts in both stability and accuracy, yet they are often bulky, power-hungry, and unable to operate outside of a well-controlled laboratory environment. Leveraging a two-photon transition in 87{}^{87}87Rb vapor and recent advances in fiber frequency combs, the authors build an optical clock to beat the current portable standards, with an architecture that can be made compact and low-power. These results point the way to a real-world optical frequency standard of even higher stability, for applications such as satellite navigation.
Optical clocks represent the hallmark of precise timekeeping. The most precise atomic clocks are laboratory-based ones that utilize transitions in the microwave/optical domain of neutral atoms or trapped ions. These clocks define an international time scales, confirm the consistency of physical constants and stimulate the search for new physics outside the Standard Model. The other area is the regime of portable atomic clocks based on warm atomic vapor, which is small, power-efficient and deployable in the field with a variety of civilian applications, including sensing, communication and navigation. Two-photon resonance and optical transition based field deployable clocks present a viable alternative that may outperform current commercial chip scale clocks by at least a factor of 10 in terms of both long-term and short-term stability. For portable clocks, two-photon transitions in alkaline earth metals are of special interest. One of the systematic inaccuracies in the optical reference is eliminated by using counter-propagating laser beams to create Doppler-free spectroscopy. At IIT Tirupati, we are engaged in developing the next generation of atomic vapor based portable frequency standard using two-photon transition in Rubidium (Rb) for atomic sensing and quantum positioning applications. This article discusses the physics behind the two-photon transition in Rubidium atoms suitable for a clock reference. Briefly, it discusses the experimental methodology for realizing an optical clock using warm rubidium vapor.
Frequency standards find wide use in navigation and timing for industry, civilian, and defense applications. Unfortunately, the very best frequency standards are bulky, power-hungry, and confined to well-controlled laboratory environments. Here the authors aim to deliver a compact, high-performance standard, the key challenge being the need to produce a strong, narrow atomic transition. They produce a superstrong signal by driving a two-photon transition in 87{}^{87}87Rb vapor that exploits a fortuitous third atomic level to greatly enhance the effective strength of the atom-light interaction, allowing short-term clock performance comparable to today's best commercial frequency standards.