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

Review of Scientific Instruments

Polarization orthogonalizer for a pair of laser beams with nearly equal frequencies

Sin Hyuk Yim, Tai Hyun Yoon, D. Cho

Published Dec 1, 2008• 13 citations
Publisher

Abstract

We have demonstrated a device to produce an overlapping pair of orthogonally polarized laser beams with a 3 GHz frequency offset out of a single laser beam containing the two frequency components with the same linear polarization. Our design is based on a Michelson interferometer formed by a polarizing beam splitter and two quarter-waveplates. Such a device can be used to make the polarization states of a carrier and a sideband produced through modulation mutually orthogonal. An orthogonally polarized pair of coherent laser beams can be used for an interferometric measurement of a small displacement in a heterodyne scheme or to produce a large-contrast coherent population trapping signal from alkali metal atoms. As a demonstration we used the device to achieve 40% contrast for a coherent population trapping signal from a rubidium vapor cell.

DOI
10.1063/1.3040499

Related papers

Selected detection of polarization for simultaneous laser locking and high-contrast coherent population trapping resonance

Suping Qu, Yi Xin Yin, Xianyang Lu

We present a new polarization-selective detection scheme that enables simultaneous dual-frequency laser stabilization and implementation of high-contrast coherent population trapping (CPT) resonance. The proposed configuration splits elliptically polarized light into two optical paths after atomic interaction. The component reflected from the polarizing beam splitter, containing Doppler-broadened spectral features, is employed for precise laser frequency locking. The reflected signal exhibits a frequency discrimination slope nine times steeper than that of the transmitted polarizing beam splitter component. Simultaneously, the transmitted component isolates the CPT resonance signals from the positive and negative first-order sidebands for microwave frequency stabilization. Experiment demonstrates excellent agreement with theoretical simulations derived from the Liouville equation. Compared with conventional circular polarization methods, this approach achieves a fourfold enhancement in short-term frequency stability. These advancements make the technique particularly promising for developing compact CPT atomic clocks with improved metrological performance.

Review of Scientific Instruments•Dec 1, 2025•0 citations

High-Performance Coherent Population Trapping Clock with Polarization Modulation

Peter Yun, François Tricot, Claudio Eligio Calosso +5 more

The authors use a single laser beam with synchronously modulated polarization and phase to trap atoms in a superposition state, decoupled from the light. Thanks to the linear architecture of this setup, it can serve as a compact, high-performance vapor-cell atomic clock. Such systems based on coherent population trapping are desired as successors to the well-known rubidium clock, particularly for applications in navigation and telecommunication. This setup offers frequencies an order of magnitude more stable than from a typical industrial clock.

arXiv:1610.00170•Physical Review Applied•Jan 25, 2017•102 citations

High-Performance Coherent Population Trapping Clock with Polarization Modulation

Peter Yun, François Tricot, Claudio Eligio Calosso +5 more

The authors use a single laser beam with synchronously modulated polarization and phase to trap atoms in a superposition state, decoupled from the light. Thanks to the linear architecture of this setup, it can serve as a compact, high-performance vapor-cell atomic clock. Such systems based on coherent population trapping are desired as successors to the well-known rubidium clock, particularly for applications in navigation and telecommunication. This setup offers frequencies an order of magnitude more stable than from a typical industrial clock.

•Jan 1, 2017•88 citations

High-performance coherent population-trapping configuration with polarization conversion and multiple constructive interference

Qu suping, Yi Yin

This scheme is based on a Michelson interferometer in which the relative optical path difference between the two arms is adjusted to control the relative phase between the copropagating left- and right-handed ( σ + - σ − ) circularly polarized light. This configuration converts the dominant ±1 st sidebands from parallel to orthogonal linear polarizations, while the 0 th sideband becomes circularly polarized light. The ±1 st sidebands, forming a double-Λ configuration, interact with 87 Rb atoms to generate an interference-enhanced coherent population trapping (CPT) resonance. A partial reflector placed behind the vapor cell enables multiple interactions between the σ + - σ − circularly polarized light and the atoms. After the polarizer, only the +1 st sideband resonance is detected; the −1 st sideband is completely suppressed, and the 0 th sideband is partially attenuated, thereby reducing the light background. Under the same conditions, the multi-pass configuration improves the CPT contrast fourfold and reduces noise by roughly half an order of magnitude compared with the single-pass case. With only a few additional optical components, this scheme improves both contrast and noise, positioning it as a promising candidate for high-performance CPT atomic clocks.

Applied Optics•Oct 8, 2026•0 citations

Production of a coherent pair of light beams with a microwave frequency difference from a single extended-cavity diode laser

Sin Hyuk Yim, D. Cho

We produced a pair of coherent laser beams with a 3-GHz frequency difference by optically phase locking two modes from a single, multimode extended-cavity diode laser. This method is complementary to either a direct modulation or an optical phase locking of two independent lasers. A large differential frequency shift between the two modes of the laser allows efficient phase locking. We developed a simple theory to account for the large differential frequency shift. Allan deviation of the beat frequency when the two modes are phase-locked drops as an inverse of the measurement time and it reaches 10(-14) when the time is 1 h. Coherent population trapping spectroscopy of Rb atoms using the phase-locked beams resulted in a spectrum as narrow as that of the case using direct modulation by a stable frequency synthesizer.

Review of Scientific Instruments•Feb 1, 2010•6 citations

Laser frequency stabilization using Doppler-free polarization-rotation spectroscopy based on coherent resonance in a miniature 87 Rb vapor cell

祝孝杰 Zhu Xiaojie, RenPing Sun, WeiHao Zhao +4 more

Abstract Locking laser frequencies to Doppler-free spectra produced by the interaction of light with alkali atoms in a vapor cell is a promising approach for realizing compact atomic optical frequency reference. In this work, we employ counter-propagating monochromatic laser beams with a polarization angle of 45° to interact with 87 Rb atoms in a 3 mm cubic vapor cell, inducing coherent resonance. By detecting the laser polarization rotation, we obtain a Doppler free spectral line, which is used as a reference for laser frequency locking, thus realizing an optical reference. We build two nominally identical systems and measure their beatnote, yielding a fractional frequency stability of 5.3×10 -13 at 1 s. This study demonstrates that the proposed scheme is a competitive approach for realizing high performance compact atomic optical reference.

Chinese Physics B•Aug 20, 2026•0 citations
We have demonstrated a device to produce an overlapping pair of orthogonally polarized laser beams with a 3 GHz frequency offset out of a single laser beam containing the two frequency components with the same linear polarization. Our design is based on a Michelson interferometer formed by a polarizing beam splitter and two quarter-waveplates. Such a device can be used to make the polarization states of a carrier and a sideband produced through modulation mutually orthogonal. An orthogonally polarized pair of coherent laser beams can be used for an interferometric measurement of a small displacement in a heterodyne scheme or to produce a large-contrast coherent population trapping signal from alkali metal atoms. As a demonstration we used the device to achieve 40% contrast for a coherent population trapping signal from a rubidium vapor cell.
We present a new polarization-selective detection scheme that enables simultaneous dual-frequency laser stabilization and implementation of high-contrast coherent population trapping (CPT) resonance. The proposed configuration splits elliptically polarized light into two optical paths after atomic interaction. The component reflected from the polarizing beam splitter, containing Doppler-broadened spectral features, is employed for precise laser frequency locking. The reflected signal exhibits a frequency discrimination slope nine times steeper than that of the transmitted polarizing beam splitter component. Simultaneously, the transmitted component isolates the CPT resonance signals from the positive and negative first-order sidebands for microwave frequency stabilization. Experiment demonstrates excellent agreement with theoretical simulations derived from the Liouville equation. Compared with conventional circular polarization methods, this approach achieves a fourfold enhancement in short-term frequency stability. These advancements make the technique particularly promising for developing compact CPT atomic clocks with improved metrological performance.
The authors use a single laser beam with synchronously modulated polarization and phase to trap atoms in a superposition state, decoupled from the light. Thanks to the linear architecture of this setup, it can serve as a compact, high-performance vapor-cell atomic clock. Such systems based on coherent population trapping are desired as successors to the well-known rubidium clock, particularly for applications in navigation and telecommunication. This setup offers frequencies an order of magnitude more stable than from a typical industrial clock.
The authors use a single laser beam with synchronously modulated polarization and phase to trap atoms in a superposition state, decoupled from the light. Thanks to the linear architecture of this setup, it can serve as a compact, high-performance vapor-cell atomic clock. Such systems based on coherent population trapping are desired as successors to the well-known rubidium clock, particularly for applications in navigation and telecommunication. This setup offers frequencies an order of magnitude more stable than from a typical industrial clock.
This scheme is based on a Michelson interferometer in which the relative optical path difference between the two arms is adjusted to control the relative phase between the copropagating left- and right-handed ( σ + - σ − ) circularly polarized light. This configuration converts the dominant ±1 st sidebands from parallel to orthogonal linear polarizations, while the 0 th sideband becomes circularly polarized light. The ±1 st sidebands, forming a double-Λ configuration, interact with 87 Rb atoms to generate an interference-enhanced coherent population trapping (CPT) resonance. A partial reflector placed behind the vapor cell enables multiple interactions between the σ + - σ − circularly polarized light and the atoms. After the polarizer, only the +1 st sideband resonance is detected; the −1 st sideband is completely suppressed, and the 0 th sideband is partially attenuated, thereby reducing the light background. Under the same conditions, the multi-pass configuration improves the CPT contrast fourfold and reduces noise by roughly half an order of magnitude compared with the single-pass case. With only a few additional optical components, this scheme improves both contrast and noise, positioning it as a promising candidate for high-performance CPT atomic clocks.
We produced a pair of coherent laser beams with a 3-GHz frequency difference by optically phase locking two modes from a single, multimode extended-cavity diode laser. This method is complementary to either a direct modulation or an optical phase locking of two independent lasers. A large differential frequency shift between the two modes of the laser allows efficient phase locking. We developed a simple theory to account for the large differential frequency shift. Allan deviation of the beat frequency when the two modes are phase-locked drops as an inverse of the measurement time and it reaches 10(-14) when the time is 1 h. Coherent population trapping spectroscopy of Rb atoms using the phase-locked beams resulted in a spectrum as narrow as that of the case using direct modulation by a stable frequency synthesizer.
Abstract Locking laser frequencies to Doppler-free spectra produced by the interaction of light with alkali atoms in a vapor cell is a promising approach for realizing compact atomic optical frequency reference. In this work, we employ counter-propagating monochromatic laser beams with a polarization angle of 45° to interact with 87 Rb atoms in a 3 mm cubic vapor cell, inducing coherent resonance. By detecting the laser polarization rotation, we obtain a Doppler free spectral line, which is used as a reference for laser frequency locking, thus realizing an optical reference. We build two nominally identical systems and measure their beatnote, yielding a fractional frequency stability of 5.3×10 -13 at 1 s. This study demonstrates that the proposed scheme is a competitive approach for realizing high performance compact atomic optical reference.