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

Optical Engineering

Ultraviolet and blue stimulated emission from Cs alkali vapor pumped using two-photon absorption and four-wave mixing

Ricardo C. Davila, Christopher A. Rice, Nathan B. Terry, Glen P. Perram

Published Dec 9, 2024• 0 citations
Publisher

Abstract

Stimulated emission on the ultraviolet and blue transitions in Cs has been achieved by pumping via two-photon absorption and four-wave mixing for the pump transition 62S12→82D32,52. The emission performance of the optically pumped cesium vapor laser operating in ultraviolet and blue has been extended to 650 nJ/pulse for 387 nm, 1 to 3 μJ/pulse for 388 nm, 200 nJ/pulse for 455 nm, and 500 nJ/pulse for 459 nm. Emission performance improves dramatically as the cesium vapor density is increased, and no scaling limitations associated with energy pooling or ionization kinetics have been observed.

DOI
10.1117/1.oe.63.12.126101

Related papers

Wavelength diversity in optically pumped alkali vapor lasers

Glen P. Perram

Alternative wavelengths for optically pumped alkali vapor lasers have been developed using single photon excitation of higher lying P-states, stimulated Raman processes, two-photon excitation of S and D states, and electric quadruple excitation on S-D transitions. Two photon excitation of Cs 72D leads to competing and cascade lasing producing red and infrared lasers operating on the D-P transitions, followed by ultraviolet, blue, the standard near infrared DPAL transitions operating on P-S transitions. The S-D pump transitions are fully bleached at pump intensities exceeding 1 MW/cm2, allowing for lasing transitions that terminate on the ground state. The kinetics of these systems are complex due to competition for population inversion among the many optical transitions. An optically pumped mid-infrared rubidium pulsed, mirrorless laser has also been demonstrated in a heat pipe along both the 62P3/2 - 62S1/2 transition at 2.73 μm and the 62P1/2 - 62S1/2 transition at 2.79 μm with a maximum energy of ~100 nJ. Performance improves dramatically as the rubidium vapor density is increased, in direct contradiction with the prior work. No scaling limitations associated with energy pooling or ionization kinetics have been observed. Practical application for infrared counter measures depends on the further development of blue diode pump sources. Finally, stimulated electronic Raman scattering and hyper-Raman processes in potassium vapor near the D1 and D2 lines have been observed using a stable resonator and pulsed laser excitation. First and second order Stokes and anti-Stokes lines were observed simultaneously and independently for a pump laser tuning range exceeding 70 cm-1. When the pump is tuned between the K D1 and D2 lines, an efficient hyper-Raman process dominates with a slope efficiency that exceeds 10%. Raman shifted laser may be useful as a target illuminator or atmospheric compensation beacon for a high power diode pumped alkali laser.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jan 13, 2017•1 citation

Generation of coherent blue light via bichromatic pumping in cesium vapor

Guiyuan Ge, Tian Li, Guoqing Zhang +10 more

Diode-pumped alkali lasers, possessing high efficiency and narrow linewidth, can provide feasible solutions for wavelength ranges difficult to reach by commercial lasers. In this study, we investigate a generation of coherent blue light (CBL) via four-wave mixing (FWM)-based up-conversion processes in cesium (Cs) vapor. A bichromatic pumping scheme with 852- and 917-nm lasers drives the Cs atoms to the 6 D 5/2 excited level, followed by cascaded decay of 6 D 5/2 → 7 P 3/2 → 6 S 1/2 , producing 456-nm CBL under phase matching conditions. The fluorescence in multiple bands from blue to near- and far-infrared in the FWM process is demonstrated under different experimental conditions. To optimize the experimental parameters, we investigate the dependence of 456-nm CBL on the vapor temperature, frequency, and intensity of the two pump lasers. A maximum power of 2.94 mW is achieved with pump powers of 430 mW (for 852 nm) and 470 mW (for 917 nm). The corresponding conversion efficiency is 1.5%/W, three-fold higher than those in previous studies. Our results can contribute to fundamental research on atom—photon interactions and quantum metrology.

Frontiers of Physics•Mar 6, 2023•7 citations

Coherent blue light enhancement via repumping laser in cesium vapor

Wen-Yi Huang, Baodong Yang, Fan Jian +2 more

We demonstrate the generation of coherent and collimated blue light (CBL) based on cesium (Cs) 6S1/2(F = 4)→6P3/2(F' = 5)→6D5/2(F'' = 6)→7P3/2(F' = 5)→6S1/2(F = 4) diamond-type atomic system in a heated vapor cell. Two infrared pumping lasers with wavelengths at 852 nm (6S1/2→6P3/2) and 917 nm (6P3/2→6D5/2), provide step-wise excitation to the 6D5/2 excited state, and induce strong two-photon coherence between the 6S1/2 state and 6D5/2 state. The atoms undergo a double cascade accompanied with the amplified spontaneous emission at 15.1 μm via the 7P3/2 intermediate excited state, and produce a beam of 455 nm (7P3/2→6S1/2) CBL with highly spatiotemporal coherence through a parametric four-wave mixing process. We investigate the influence of experimental parameters such as polarization combination of the two pumping lasers, and their power, and the temperature of Cs vapor cell on the CBL. Especially, we add a beam of 894 nm laser operating at the 6S1/2(F = 3) →6P1/2 transition as repumping laser, which can pump atoms back to the 6S1/2(F = 4) state from the 6S1/2(F = 3) state, thus significantly improving the power of CBL. This technique of the CBL enhancement via optical pumping is also useful for the other alkali metal atoms.

Acta Physica Sinica•Jan 1, 2022•3 citations

Pumping of atomic alkali lasers by photoexcitation of a resonance line blue satellite and alkali-rare gas excimer dissociation

Jason D. Readle, C. J. Wagner, J. T. Verdeyen +3 more

Photoassociation of alkali-rare gas atomic collision pairs provides an alternative approach to optically pumping atomic alkali lasers. Lasing on the 6 P21/2→6 S21/2 (D1) transition of Cs has been observed when the blue satellite of the 6 P23/2←6 S21/2 (D2) transition, peaking at ∼837 nm for mixtures of Cs vapor, Ar, and ethane, is pumped by a pulsed dye laser. For 50% output coupling, laser threshold with respect to absorbed pump energy is ∼40 μJ at T=435 K and the slope efficiency approaches 10%. The measured spectral breadth for the blue satellite (≳5 nm at 410 K) will accommodate cw pumping of the Cs laser with conventional semiconductor lasers.

Applied Physics Letters•Jun 22, 2009•42 citations

Cesium laser operating in the blue by direct optical excitation of the 72P 3/2 state

Kirk C. Brown, Glen P. Perram

A blue alkali laser operating by direct optical excitation of the 72P3/2 state of cesium is demonstrated. A mixture of cesium vapor and various buffer gases (4He, CH4, C2H6) were pumped with the output of a pulsed dye laser in a heated glass cell. The spin-orbit mixing and fluorescence quenching cross sections were calculated for each buffer gas using the time-dependent D1 (459 nm) side fluorescence. At certain temperatures and buffer gas pressures, a spatially coherent blue beam is produced in the forward direction. An analysis of the spectrum shows this beam contains both D1 amplified spontaneous emission (ASE) and Stimulated Raman Scattering (SRS).

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Feb 2, 2011•7 citations

Two-Photon Resonant Four-Wave Mixing And Multiphoton Ionization Of Cesium In A Heat Pipe Oven

S. M. Hamadani, John A. D. Stockdale, R. N. Compton

Optical pumping of cesium vapor in a heat pipe oven in which the energy of two near-infrared photons is close to the 6D states results in high conversion efficiency (up to 1.7%) of the near-infrared pump light to intense blue, forward-propagating radiation. The blue light corresponds to the 7P-6S transition. The dependence of conversion efficiency upon focusing conditions, cell length, and pump intensity is presented. Absorption and gain coefficients are measured in a second heat pipe. The results are discussed in terms of optically pumped stimulated emission (OPSE), stimulated electronic Raman scattering (SERS), and subsequent nonlinear four-wave mixing of two pump-laser photons and one SERS or OPSE infrared photon leading to parametric generation at w = 2WL -wiR.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jun 30, 1986•0 citations
Stimulated emission on the ultraviolet and blue transitions in Cs has been achieved by pumping via two-photon absorption and four-wave mixing for the pump transition 62S12→82D32,52. The emission performance of the optically pumped cesium vapor laser operating in ultraviolet and blue has been extended to 650 nJ/pulse for 387 nm, 1 to 3 μJ/pulse for 388 nm, 200 nJ/pulse for 455 nm, and 500 nJ/pulse for 459 nm. Emission performance improves dramatically as the cesium vapor density is increased, and no scaling limitations associated with energy pooling or ionization kinetics have been observed.
Alternative wavelengths for optically pumped alkali vapor lasers have been developed using single photon excitation of higher lying P-states, stimulated Raman processes, two-photon excitation of S and D states, and electric quadruple excitation on S-D transitions. Two photon excitation of Cs 72D leads to competing and cascade lasing producing red and infrared lasers operating on the D-P transitions, followed by ultraviolet, blue, the standard near infrared DPAL transitions operating on P-S transitions. The S-D pump transitions are fully bleached at pump intensities exceeding 1 MW/cm2, allowing for lasing transitions that terminate on the ground state. The kinetics of these systems are complex due to competition for population inversion among the many optical transitions. An optically pumped mid-infrared rubidium pulsed, mirrorless laser has also been demonstrated in a heat pipe along both the 62P3/2 - 62S1/2 transition at 2.73 μm and the 62P1/2 - 62S1/2 transition at 2.79 μm with a maximum energy of ~100 nJ. Performance improves dramatically as the rubidium vapor density is increased, in direct contradiction with the prior work. No scaling limitations associated with energy pooling or ionization kinetics have been observed. Practical application for infrared counter measures depends on the further development of blue diode pump sources. Finally, stimulated electronic Raman scattering and hyper-Raman processes in potassium vapor near the D1 and D2 lines have been observed using a stable resonator and pulsed laser excitation. First and second order Stokes and anti-Stokes lines were observed simultaneously and independently for a pump laser tuning range exceeding 70 cm-1. When the pump is tuned between the K D1 and D2 lines, an efficient hyper-Raman process dominates with a slope efficiency that exceeds 10%. Raman shifted laser may be useful as a target illuminator or atmospheric compensation beacon for a high power diode pumped alkali laser.
Diode-pumped alkali lasers, possessing high efficiency and narrow linewidth, can provide feasible solutions for wavelength ranges difficult to reach by commercial lasers. In this study, we investigate a generation of coherent blue light (CBL) via four-wave mixing (FWM)-based up-conversion processes in cesium (Cs) vapor. A bichromatic pumping scheme with 852- and 917-nm lasers drives the Cs atoms to the 6 D 5/2 excited level, followed by cascaded decay of 6 D 5/2 → 7 P 3/2 → 6 S 1/2 , producing 456-nm CBL under phase matching conditions. The fluorescence in multiple bands from blue to near- and far-infrared in the FWM process is demonstrated under different experimental conditions. To optimize the experimental parameters, we investigate the dependence of 456-nm CBL on the vapor temperature, frequency, and intensity of the two pump lasers. A maximum power of 2.94 mW is achieved with pump powers of 430 mW (for 852 nm) and 470 mW (for 917 nm). The corresponding conversion efficiency is 1.5%/W, three-fold higher than those in previous studies. Our results can contribute to fundamental research on atom—photon interactions and quantum metrology.
We demonstrate the generation of coherent and collimated blue light (CBL) based on cesium (Cs) 6S1/2(F = 4)→6P3/2(F' = 5)→6D5/2(F'' = 6)→7P3/2(F' = 5)→6S1/2(F = 4) diamond-type atomic system in a heated vapor cell. Two infrared pumping lasers with wavelengths at 852 nm (6S1/2→6P3/2) and 917 nm (6P3/2→6D5/2), provide step-wise excitation to the 6D5/2 excited state, and induce strong two-photon coherence between the 6S1/2 state and 6D5/2 state. The atoms undergo a double cascade accompanied with the amplified spontaneous emission at 15.1 μm via the 7P3/2 intermediate excited state, and produce a beam of 455 nm (7P3/2→6S1/2) CBL with highly spatiotemporal coherence through a parametric four-wave mixing process. We investigate the influence of experimental parameters such as polarization combination of the two pumping lasers, and their power, and the temperature of Cs vapor cell on the CBL. Especially, we add a beam of 894 nm laser operating at the 6S1/2(F = 3) →6P1/2 transition as repumping laser, which can pump atoms back to the 6S1/2(F = 4) state from the 6S1/2(F = 3) state, thus significantly improving the power of CBL. This technique of the CBL enhancement via optical pumping is also useful for the other alkali metal atoms.
Photoassociation of alkali-rare gas atomic collision pairs provides an alternative approach to optically pumping atomic alkali lasers. Lasing on the 6 P21/2→6 S21/2 (D1) transition of Cs has been observed when the blue satellite of the 6 P23/2←6 S21/2 (D2) transition, peaking at ∼837 nm for mixtures of Cs vapor, Ar, and ethane, is pumped by a pulsed dye laser. For 50% output coupling, laser threshold with respect to absorbed pump energy is ∼40 μJ at T=435 K and the slope efficiency approaches 10%. The measured spectral breadth for the blue satellite (≳5 nm at 410 K) will accommodate cw pumping of the Cs laser with conventional semiconductor lasers.
A blue alkali laser operating by direct optical excitation of the 72P3/2 state of cesium is demonstrated. A mixture of cesium vapor and various buffer gases (4He, CH4, C2H6) were pumped with the output of a pulsed dye laser in a heated glass cell. The spin-orbit mixing and fluorescence quenching cross sections were calculated for each buffer gas using the time-dependent D1 (459 nm) side fluorescence. At certain temperatures and buffer gas pressures, a spatially coherent blue beam is produced in the forward direction. An analysis of the spectrum shows this beam contains both D1 amplified spontaneous emission (ASE) and Stimulated Raman Scattering (SRS).
Optical pumping of cesium vapor in a heat pipe oven in which the energy of two near-infrared photons is close to the 6D states results in high conversion efficiency (up to 1.7%) of the near-infrared pump light to intense blue, forward-propagating radiation. The blue light corresponds to the 7P-6S transition. The dependence of conversion efficiency upon focusing conditions, cell length, and pump intensity is presented. Absorption and gain coefficients are measured in a second heat pipe. The results are discussed in terms of optically pumped stimulated emission (OPSE), stimulated electronic Raman scattering (SERS), and subsequent nonlinear four-wave mixing of two pump-laser photons and one SERS or OPSE infrared photon leading to parametric generation at w = 2WL -wiR.