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:1207.4853 · Journal of Physics B Atomic Molecular and Optical Physics

Frequency evaluation of collimated blue light generated by wave mixing in Rb vapour

A. M. Akulshin, Christopher Perrella, Gar-Wing Truong, Russell McLean, Andre Nicholas Luiten

Published Nov 30, 2012• 24 citations
arXivHTMLPDF

Abstract

An evaluation of the absolute frequency and tunability of collimated blue light (CBL) generated in warm Rb vapour excited by low-power cw laser radiation at 780 nm and 776 nm has been performed using a Fabry–Perot interferometer and a blue diode laser. For the conditions of our experiments, the CBL tuning range is more than 250 MHz around the resonant frequency of the 85 Rb 5S 1/2 ( F = 3)→6P 3/2 ( F ′ = 4) transition. A simple technique for stabilizing the power and frequency of the CBL to within a few per cent and 10 MHz, respectively, is suggested and demonstrated.

DOI
10.1088/0953-4075/45/24/245503

Related papers

Linewidth of frequency up-converted radiation in alkali vapours

A. M. Akulshin, Christopher Perrella, Gar-Wing Truong +2 more

We present a study of the spectral linewidth of collimated blue light (CBL) that results from wave mixing of low-power cw laser radiation at 780 nm and 776 nm in Rb vapours. Using a high-finesse Fabry-Perot interferometer the spectral width of the CBL is found to be less than 1.3 MHz for a wide range of our experimental conditions. We also demonstrate that the measured linewidth is mainly limited by the temporal coherence of the applied laser fields rather than laser light intensities and the atomic medium itself.

•Jan 30, 2013•0 citations

Frequency characteristics of collimated blue light generated by four-wave mixing in cesium vapor

Baodong Yang, Jing Xu, Fan Jian +1 more

The frequency evaluation of collimated blue light (CBL) generated by parametric four-wave mixing (FWM) in hot atomic vapor is presented. The cesium ( 133 Cs) atoms are excited from the 6S 1/2 ground state to 8S 1/2 excited state with the 852 and 795 nm pump lasers, producing an optical field at 4.2 µm through an amplified spontaneous emission via population inversion on the 8S 1/2 → 7P 3/2 transition and the 456 nm CBL via FWM on the 7P 3/2 → 6S 1/2 transition. The frequency shift of 456 nm CBL has been measured by velocity-selective optical pumping spectral technique when the frequency of any one of two pumping lasers is tuned. The ratio of the frequency shift of 456 nm CBL to the two-photon frequency detuning of two pumping lasers is 0.8912, implying that the generated 4.2 µm light frequency is also correspondingly shifted.

Optics Letters•Jun 11, 2024•5 citations

Collimated blue light generation in rubidium vapor

Marcus Kienlen, Noah T. Holte, Hunter A. Dassonville +4 more

We describe an experiment for generating and characterizing a beam of collimated blue light (CBL) in a rubidium vapor. Two low-power, grating-feedback diode lasers, operating at 780.2 nm (5S1/2→5P3/2) and 776.0 nm (5P3/2→5D5/2), respectively, provide step-wise excitation to the 5D excited state in rubidium. Under the right experimental conditions, cascade decay through the 6P excited state will yield a collimated blue (420-nm) beam of light with high temporal and spatial coherence. We investigate the production of a blue beam under a variety of experimental conditions and characterize the spatial coherence and spectral characteristics. This experiment provides advanced undergraduate students with a unique opportunity to investigate nonlinear optical phenomena in the laboratory and uses equipment that is commonly available in laboratories equipped to investigate diode-laser-based absorption spectroscopy in rubidium.

American Journal of Physics•May 20, 2013•23 citations

Coherent and collimated blue light generated by four-wave mixing in Rb vapour

A. M. Akulshin, Russell McLean, Andrei I. Sidorov +1 more

We investigate frequency up-conversion of low power cw resonant radiation in Rb vapour as a function of various experimental parameters. We present evidence that the process of four wave mixing is responsible for unidirectional blue light generation and that the phase matching conditions along a light-induced waveguide determine the direction and divergence of the blue light. Velocity-selective excitation to the 5D level via step-wise and two-photon processes results in a Doppler-free dependence on the frequency detuning of the applied laser fields from the respective dipole-allowed transitions. Possible schemes for ultraviolet generation are discussed.

arXiv:0910.2292•Optics Express•Nov 30, 2009•126 citations

Comparison of collimated blue-light generation in 85Rb atoms via the D1 and D2 lines

Nikunj Prajapati, A. M. Akulshin, Irina V. Novikova

We experimentally and theoretically studied the characteristics of the collimated blue light (CBL) produced in Rb85 vapor by two resonant laser fields exciting atoms into the 5D3/2 state, using either the 5P1/2 or the 5P3/2 intermediate state. We compared the CBL output at different values of frequency detunings, powers, and polarizations of the pump lasers in these two cases and confirmed the observed trends using a simple theoretical model. We found that in general the CBL yield was higher for the the D1 excitation scheme compared to the D2 excitation scheme under similar conditions. We also demonstrated the importance of the repump laser, preventing the accumulation of atomic population in the uncoupled hyperfine ground state, which resulted in nearly an order of magnitude increase in CBL power output. One interesting finding was the existence of the optimal power ratios between the two pump lasers, leading to the maximum blue-light power, observed both in the experiment and in the calculations.

arXiv:1802.07305•Journal of the Optical Society of America B•Apr 17, 2018•20 citations

Collimated blue light enhancement in velocity-selective pumped Rb vapour

A. M. Akulshin, A A Orel, Russell McLean

The effect of hyperfine optical pumping on the parametric four-wave mixing process responsible for the generation of collimated blue light (CBL) in alkali atoms is explored. Over a wide range of atomic densities (4.5 × 10 10 cm −3 ⩽ N ⩽ 1.4 × 10 11 cm −3 ), a more than ten-fold enhancement of CBL is obtained from optical pumping produced by an additional laser. Pulsed optical pumping has been applied to investigate the temporal characteristics of CBL generation. It is shown that optical pumping offers efficient control of the mixing process and the collimated light generation that may be useful for probing a small number of atoms.

Journal of Physics B Atomic Molecular and Optical Physics•Dec 9, 2011•44 citations
An evaluation of the absolute frequency and tunability of collimated blue light (CBL) generated in warm Rb vapour excited by low-power cw laser radiation at 780 nm and 776 nm has been performed using a Fabry–Perot interferometer and a blue diode laser. For the conditions of our experiments, the CBL tuning range is more than 250 MHz around the resonant frequency of the 85 Rb 5S 1/2 ( F = 3)→6P 3/2 ( F ′ = 4) transition. A simple technique for stabilizing the power and frequency of the CBL to within a few per cent and 10 MHz, respectively, is suggested and demonstrated.
We present a study of the spectral linewidth of collimated blue light (CBL) that results from wave mixing of low-power cw laser radiation at 780 nm and 776 nm in Rb vapours. Using a high-finesse Fabry-Perot interferometer the spectral width of the CBL is found to be less than 1.3 MHz for a wide range of our experimental conditions. We also demonstrate that the measured linewidth is mainly limited by the temporal coherence of the applied laser fields rather than laser light intensities and the atomic medium itself.
The frequency evaluation of collimated blue light (CBL) generated by parametric four-wave mixing (FWM) in hot atomic vapor is presented. The cesium ( 133 Cs) atoms are excited from the 6S 1/2 ground state to 8S 1/2 excited state with the 852 and 795 nm pump lasers, producing an optical field at 4.2 µm through an amplified spontaneous emission via population inversion on the 8S 1/2 → 7P 3/2 transition and the 456 nm CBL via FWM on the 7P 3/2 → 6S 1/2 transition. The frequency shift of 456 nm CBL has been measured by velocity-selective optical pumping spectral technique when the frequency of any one of two pumping lasers is tuned. The ratio of the frequency shift of 456 nm CBL to the two-photon frequency detuning of two pumping lasers is 0.8912, implying that the generated 4.2 µm light frequency is also correspondingly shifted.
We describe an experiment for generating and characterizing a beam of collimated blue light (CBL) in a rubidium vapor. Two low-power, grating-feedback diode lasers, operating at 780.2 nm (5S1/2→5P3/2) and 776.0 nm (5P3/2→5D5/2), respectively, provide step-wise excitation to the 5D excited state in rubidium. Under the right experimental conditions, cascade decay through the 6P excited state will yield a collimated blue (420-nm) beam of light with high temporal and spatial coherence. We investigate the production of a blue beam under a variety of experimental conditions and characterize the spatial coherence and spectral characteristics. This experiment provides advanced undergraduate students with a unique opportunity to investigate nonlinear optical phenomena in the laboratory and uses equipment that is commonly available in laboratories equipped to investigate diode-laser-based absorption spectroscopy in rubidium.
We investigate frequency up-conversion of low power cw resonant radiation in Rb vapour as a function of various experimental parameters. We present evidence that the process of four wave mixing is responsible for unidirectional blue light generation and that the phase matching conditions along a light-induced waveguide determine the direction and divergence of the blue light. Velocity-selective excitation to the 5D level via step-wise and two-photon processes results in a Doppler-free dependence on the frequency detuning of the applied laser fields from the respective dipole-allowed transitions. Possible schemes for ultraviolet generation are discussed.
We experimentally and theoretically studied the characteristics of the collimated blue light (CBL) produced in Rb85 vapor by two resonant laser fields exciting atoms into the 5D3/2 state, using either the 5P1/2 or the 5P3/2 intermediate state. We compared the CBL output at different values of frequency detunings, powers, and polarizations of the pump lasers in these two cases and confirmed the observed trends using a simple theoretical model. We found that in general the CBL yield was higher for the the D1 excitation scheme compared to the D2 excitation scheme under similar conditions. We also demonstrated the importance of the repump laser, preventing the accumulation of atomic population in the uncoupled hyperfine ground state, which resulted in nearly an order of magnitude increase in CBL power output. One interesting finding was the existence of the optimal power ratios between the two pump lasers, leading to the maximum blue-light power, observed both in the experiment and in the calculations.
The effect of hyperfine optical pumping on the parametric four-wave mixing process responsible for the generation of collimated blue light (CBL) in alkali atoms is explored. Over a wide range of atomic densities (4.5 × 10 10 cm −3 ⩽ N ⩽ 1.4 × 10 11 cm −3 ), a more than ten-fold enhancement of CBL is obtained from optical pumping produced by an additional laser. Pulsed optical pumping has been applied to investigate the temporal characteristics of CBL generation. It is shown that optical pumping offers efficient control of the mixing process and the collimated light generation that may be useful for probing a small number of atoms.