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

arXiv:1603.05703 · Optics Letters

Cavity-enhanced frequency up-conversion in rubidium vapor

Rachel F. Offer, Johnathan W. C. Conway, Erling Riis, Sonja Franke‐Arnold, Aidan S. Arnold

Published May 2, 2016• 39 citations
arXivHTMLPDF

Abstract

We report the first use of a ring cavity to both enhance the output power and dramatically narrow the linewidth (<1 MHz) of blue light generated by four-wave mixing in a rubidium vapor cell. We find that the high output power available in our cavity-free system leads to power broadening of the generated blue light linewidth. Our ring cavity removes this limitation, allowing high output power and narrow linewidth to be achieved concurrently. As the cavity blue light is widely tunable over the Rb855S1/2F=3→6P3/2 transition, this narrow linewidth light would be suitable for near-resonant rubidium studies including, for example, second-stage laser cooling.

DOI
10.1364/ol.41.002177

Related papers

Optical cavity for enhanced parametric four-wave mixing in rubidium

E. Brekke, S. Potier

We have incorporated a ring cavity to enhance the efficiency of parametric four-wave mixing in rubidium (Rb). Using an input coupler with 95% reflectance, a finesse of 19.6±0.5 is achieved with an Rb cell inside. This increases the circulating intensity by a factor of 5.6±0.5, and through two-photon excitation on the 5s1/2→5d5/2 transition with a single excitation laser, up to 1.9±0.3 mW of power at 420 nm is generated, 50 times what was previously generated with this scheme and comparable to low-power two-step excitation. The dependence of the output on the Rb density and input power has been explored, suggesting the process may be approaching saturation. The blue output of the cavity also shows greatly improved spatial quality, combining to make this a promising source of 420 nm light for future experiments.

arXiv:1608.07603•Applied Optics•Dec 20, 2016•21 citations

Saturation and alternate pathways in four-wave mixing in rubidium

Erik Brekke, Noah Swan

We have examined the frequency spectrum of the blue light generated via four-wave mixing in a rubidium vapor cell inside a ring cavity. At high atomic density and input laser power, two distinct frequency components separated by 116±4 MHz are observed, indicating alternate four-wave mixing channels through the 6p3/2 hyperfine states. The dependence of the generated light on excitation intensity and atomic density are explored, and they indicate that the primary process has saturated. This saturation results when the excitation rate through the 6p state becomes equal to the rate through the 5p state, giving no further gain with atomic density while a quadratic intensity dependence remains.

arXiv:1812.04465•Journal of the Optical Society of America B•Jan 23, 2019•7 citations

Coherent 420 nm light generated by the cavity-enhanced four-wave mixing process in Rb vapor

Jinpeng Yuan, Hao Liu, Lirong Wang +2 more

We have generated a stable and continuously tunable single frequency (420 nm) coherent blue light (CBL) by the cavity-enhanced four-wave mixing process in Rb vapor. With the bow-tie-type ring cavity, the output power was 3.3 mW, two orders of magnitude higher than that of the CBL generated by the single-pass four-wave mixing process. The measured power stabilities of the 420 nm CBL operated at 2.5 mW and 1.5 mW for 1000 s were 2.89% and 1.88%, respectively. Under the scanning pump laser frequency, the continuously tunable range of the generated CBL reached 1.68 GHz without mode hopping. The measured beam qualities of the generated laser were M x 2 = 1.117 and M y 2 = 1.179 . The excellent performance of the 420 nm CBL was characterized by velocity transfer spectroscopy with 780 nm probe laser. This high quality short wavelength coherent light is potentially applicable to photon-atom interactions in quantum optics and fundamental research fields.

Optics Express•Jan 26, 2021•20 citations

Enhanced frequency up-conversion in Rb vapor

Aline Vernier, Sonja Franke‐Arnold, Erling Riis +1 more

We demonstrate highly efficient generation of coherent 420 nm light via up-conversion of near-infrared lasers in a hot rubidium vapor cell. By optimizing pump polarizations and frequencies we achieve a single-pass conversion efficiency of 260% per Watt, significantly higher than in previous experiments. A full exploration of the coherent light generation and fluorescence as a function of both pump frequencies reveals that coherent blue light is generated close to (85)Rb two-photon resonances, as predicted by theory, but at high vapor pressure is suppressed in spectral regions that do not support phase matching or exhibit single-photon Kerr refraction. Favorable scaling of our current 1 mW blue beam power with additional pump power is predicted.

arXiv:0911.0812•Optics Express•Jul 27, 2010•102 citations

Cavity-enhanced frequency up-conversion in rubidium vapour

Rachel F. Offer, Johnathan W. C. Conway, Erling Riis +2 more

Atomic vapours are a versatile tool for studying a wide range of nonlinear phenomena. In particular, quasi-resonant atomic systems allow processes such as electromagnetically induced transparency, fast and slow light, lasing without inversion and four wave mixing (FWM) to be studied at low light intensities. The resonant enhancement of FWM in a rubidium vapour is such that it can be used for efficient frequency up-conversion of near-infrared light (780 and 776 nm) to blue light (420 nm) [1-4].

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 1, 2017•1 citation

Nonlinear Frequency Translation in Micromachined Rb Vapor Cells

Heleni Krelman, Ori Nefesh, Liron Stern

The exceptional nonlinearity of alkali-metal vapors enables highly efficient nonlinear optical processes even at relatively low optical intensities. However, such processes have traditionally relied on centimeter-scale vapor cells. Here, we utilize a versatile chip-scale Rb vapor platform to generate coherent blue and mid-IR light in continuous-wave mode by means of resonant four-wave mixing. Optimized optical overlap with the atomic medium enables blue light generation of $\sim$20 $μ$W over a very short interaction length, while maintaining a directly measured linewidth of $\sim$1 MHz, which is presently limited by the measurement apparatus. Comparison with a conventional glassblown vapor cell further shows that the micromachined platform can achieve higher coherent blue-light generation efficiency despite its substantially shorter interaction length. Moreover, an anodically bonded Si window enables to detect coherent mid-IR emission with collected powers of $\sim$50 nW. We further characterize the temperature dependence and input-power scaling of the blue emission, confirming efficient nonlinear conversion within these compact vapor cells. This chip-scale platform provides a versatile foundation for a range of nonlinear optical functions, from precise wavelength references and quantum light sources to next-generation quantum sensors.

physics.opticsCross-listedarXiv:2605.01997•May 5, 2026•0 citations
We report the first use of a ring cavity to both enhance the output power and dramatically narrow the linewidth (<1 MHz) of blue light generated by four-wave mixing in a rubidium vapor cell. We find that the high output power available in our cavity-free system leads to power broadening of the generated blue light linewidth. Our ring cavity removes this limitation, allowing high output power and narrow linewidth to be achieved concurrently. As the cavity blue light is widely tunable over the Rb855S1/2F=3→6P3/2 transition, this narrow linewidth light would be suitable for near-resonant rubidium studies including, for example, second-stage laser cooling.
We have incorporated a ring cavity to enhance the efficiency of parametric four-wave mixing in rubidium (Rb). Using an input coupler with 95% reflectance, a finesse of 19.6±0.5 is achieved with an Rb cell inside. This increases the circulating intensity by a factor of 5.6±0.5, and through two-photon excitation on the 5s1/2→5d5/2 transition with a single excitation laser, up to 1.9±0.3 mW of power at 420 nm is generated, 50 times what was previously generated with this scheme and comparable to low-power two-step excitation. The dependence of the output on the Rb density and input power has been explored, suggesting the process may be approaching saturation. The blue output of the cavity also shows greatly improved spatial quality, combining to make this a promising source of 420 nm light for future experiments.
We have examined the frequency spectrum of the blue light generated via four-wave mixing in a rubidium vapor cell inside a ring cavity. At high atomic density and input laser power, two distinct frequency components separated by 116±4 MHz are observed, indicating alternate four-wave mixing channels through the 6p3/2 hyperfine states. The dependence of the generated light on excitation intensity and atomic density are explored, and they indicate that the primary process has saturated. This saturation results when the excitation rate through the 6p state becomes equal to the rate through the 5p state, giving no further gain with atomic density while a quadratic intensity dependence remains.
We have generated a stable and continuously tunable single frequency (420 nm) coherent blue light (CBL) by the cavity-enhanced four-wave mixing process in Rb vapor. With the bow-tie-type ring cavity, the output power was 3.3 mW, two orders of magnitude higher than that of the CBL generated by the single-pass four-wave mixing process. The measured power stabilities of the 420 nm CBL operated at 2.5 mW and 1.5 mW for 1000 s were 2.89% and 1.88%, respectively. Under the scanning pump laser frequency, the continuously tunable range of the generated CBL reached 1.68 GHz without mode hopping. The measured beam qualities of the generated laser were M x 2 = 1.117 and M y 2 = 1.179 . The excellent performance of the 420 nm CBL was characterized by velocity transfer spectroscopy with 780 nm probe laser. This high quality short wavelength coherent light is potentially applicable to photon-atom interactions in quantum optics and fundamental research fields.
We demonstrate highly efficient generation of coherent 420 nm light via up-conversion of near-infrared lasers in a hot rubidium vapor cell. By optimizing pump polarizations and frequencies we achieve a single-pass conversion efficiency of 260% per Watt, significantly higher than in previous experiments. A full exploration of the coherent light generation and fluorescence as a function of both pump frequencies reveals that coherent blue light is generated close to (85)Rb two-photon resonances, as predicted by theory, but at high vapor pressure is suppressed in spectral regions that do not support phase matching or exhibit single-photon Kerr refraction. Favorable scaling of our current 1 mW blue beam power with additional pump power is predicted.
The exceptional nonlinearity of alkali-metal vapors enables highly efficient nonlinear optical processes even at relatively low optical intensities. However, such processes have traditionally relied on centimeter-scale vapor cells. Here, we utilize a versatile chip-scale Rb vapor platform to generate coherent blue and mid-IR light in continuous-wave mode by means of resonant four-wave mixing. Optimized optical overlap with the atomic medium enables blue light generation of $\sim$20 μμμW over a very short interaction length, while maintaining a directly measured linewidth of $\sim$1 MHz, which is presently limited by the measurement apparatus. Comparison with a conventional glassblown vapor cell further shows that the micromachined platform can achieve higher coherent blue-light generation efficiency despite its substantially shorter interaction length. Moreover, an anodically bonded Si window enables to detect coherent mid-IR emission with collected powers of $\sim$50 nW. We further characterize the temperature dependence and input-power scaling of the blue emission, confirming efficient nonlinear conversion within these compact vapor cells. This chip-scale platform provides a versatile foundation for a range of nonlinear optical functions, from precise wavelength references and quantum light sources to next-generation quantum sensors.