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

European Quantum Electronics Conference (EQEC)

Slowing cold molecules with pulsed optical lattices

Guangjiong Dong, Weiping Lu, P. F. Barker, Mikhail N. Shneider

Published Jan 1, 2003• 0 citations
Publisher

Abstract

This work presents the proposed schemes for decelerating cold molecules created in pulsed supersonic expansions using pulsed optical lattices. The first scheme relies on the application of a decelerating optical lattice with a dipole-potential well depth of approximately 1 K, created by rapidly chirping medium-intensity fields in the 10 W/cm/sup 2/ range. This scheme is an optical analog of the Start decelerator that has been successfully used to slow a range of polar molecules. A significant fraction (about 10%) of the very heavy I/sub 2 /molecules in an Ar buffer gas is shown to be slowed by using this method over sub-microsecond time scales. In the second technique, an optical lattice with larger well depth in the 100 K range travelling at half the supersonic beam velocity is used to trap a significant fraction of the cold, high-velocity molecules. This technique is developed based on the property of periodic motion of the trapped molecules in the optical lattice; the molecules reverse their initial (relative) velocities in the lattice reference frame after half a period. Using this method the cold molecules can be transferred from high speed to zero velocity on nanosecond time scales. As an example, 33% of a CO molecule beam (1 K) with a velocity of 230 m/s is slowed utilising optical intensities of less than 10/sup 12/ W/cm/sup 2/.

DOI
10.1109/eqec.2003.1314159

Related papers

Decelerating and bunching molecules with pulsed traveling optical lattices

Guangjiong Dong, Weiping Lu, P. F. Barker

We investigate the deceleration and bunching of cold molecules in a pulsed supersonic jet using a far-off-resonant optical lattice traveling with a constant velocity. Using an analytical treatment, we show that by choosing the lattice velocity equal to half the supersonic beam velocity and by optimizing the pulse duration, a significant fraction $(\ensuremath{\sim}33%)$ of translationally cold (1 K) CO molecules from a supersonic molecular beam can be decelerated to zero velocity, and simultaneously bunched in velocity space. Due to the large difference of polarizability to mass ratio between the buffer gas and the CO molecules in the pulsed jet, the buffer gas can be precluded from the fraction of stationary molecules by choosing a suitable pulse duration. Furthermore, we find that spatial bunching within the optical lattice is induced and the position of the bunch within the lattice can be chosen by varying the lattice velocity.

Physical Review A•Jan 23, 2004•31 citations

Slowing molecules by optical microlinear deceleration

P. F. Barker, Mikhail N. Shneider

We study the creation of stationary cold molecules by rapid deceleration of supersonically cooled molecules in a high-intensity pulsed optical lattice. Using the heavy molecule ${\mathrm{I}}_{2}$ as an example we predict the evolution of the velocity distribution function of the ensemble during the deceleration period, and show that stationary cold molecules with temperatures below 1 K and densities of approximately ${10}^{12}{\mathrm{cm}}^{\ensuremath{-}3}$ can be produced over length scales of hundreds of micrometers on submicrosecond time scales.

Physical Review A•Dec 12, 2002•55 citations

Creating cold stationary molecular gases by optical Stark deceleration

Alexis I. Bishop, L Wang, P. F. Barker

The deceleration of molecules from cold molecular beams using electric and magnetic fields has become an important means for producing stationary, cold dipolar or paramagnetic molecular gases that can be trapped and potentially cooled to ultra-cold temperatures in the μK range. We report on a general scheme for the creation of cold molecules of essentially any type by deceleration of a cold molecular beam using intense optical fields. Deceleration of benzene molecules to zero velocity is achieved by utilizing a single half oscillation of the center-of-mass motion of the molecules within a moving optical lattice. The lattice traveling at half the speed of the molecular beam is created by the interference of two near-counter-propagating fields at different frequencies. We show that by rapidly switching on the optical lattice for approximately the time required for a half oscillation, a bunch of approximately 10 5 benzene molecules can be rapidly decelerated and brought to rest in the laboratory frame.

New Journal of Physics•Jul 23, 2010•23 citations

Multistage optical Stark decelerator for a pulsed supersonic beam with a quasi-cw optical lattice

Yaling Yin, Qi Zhou, Lianzhong Deng +2 more

We propose a new scheme to realize a multistage optical Stark deceleration for a supersonic molecular beam using a time-varying red-detuned quasi-cw optical lattice with a length of up to 10 mm. We analyze the motion of the slowed molecules inside the optical decelerator, and study the dependences of the velocity of the slowed molecular packet on the synchronous phase angle and the number of the deceleration stages (i.e., the number of the optical-lattice cells) by using Monte-Carlo method. Our study shows that the proposed optical Stark decelerator cannot only efficiently slow a pulsed supersonic beam from 230 m/s to zero (standstill), but also obtain an ultracold molecular packet with a temperature of sub-mK due to bunching effect in the multistage optical Stark decelerator, which can be trapped in the optical lattice by rapidly turning off the modulation signal of the lattice. Also, we compare the decelerated results of our multistage optical Stark decelerator with a single-stage optical one, and find that our scheme cannot only obtain a colder molecular packet under the same molecular-beam parameters and deceleration conditions, but also be directly used to trap the slowed cold molecules after the deceleration, while don't need to use another molecular trap.

Optics Express•Jun 11, 2009•19 citations

Theoritical research on optical Stark deceleration and trapping of neutral molecular beams based on modulated optical lattices

Li Xiao-Yun, Sun Bo-Wen, Xu Zheng-Qian +3 more

According to the optical Stark deceleration theory of using a stationary quasi-cw red-detuned optical lattice to slow and trap an arbitrary pulsed molecular beam, we propose a novel idea of using a modulated optical lattice instead of a stationary one to realize a multistage optical Stark deceleration. We analyze the motion of the decelerated molecules inside the optical decelerator, and study the dependence of the velocity of the decelerated molecular packet on the synchronous phase angle and the number of the deceleration stages (i.e. half the number of the optical-lattice cells) by using the Monte-Carlo method. The simulation results show that it takes longer time for the molecules to reach the detector as the number of the deceleration stages increases. The decelerated molecular wave packets are gradually separated from the large wave packets of the original molecular velocity distribution. And the higher the number of the deceleration stages, the lower the decelerated molecular speed is. In addition, we also study the influence of the initial phase angle of synchronous molecules under the same conditions. It is demonstrated that the higher the initial phase angle of synchronous molecules, the lower the decelerated molecular speed is and the smaller the number of molecules in the deceleration wave packet, so the phase space is compressed. The result also shows that the modulated optical Stark decelerator does not have the process of molecular free flight, and thus improving the efficiency of deceleration for molecules. The ultra-cold molecules can be trapped in the optical lattice by rapidly turning off the modulation signal of the lattice. Comparing with the previous scheme, the doubled number of the deceleration stages is reached in the same optical lattice length since a modulated optical lattice is used. For a length of optical lattice of 3.71 mm, theoretical simulation results demonstrate that the speed of methane molecules is decelerated from 280 m/s to 172 m/s. Comparing with the previous results from 280 m/s to 232 m/s, the deceleration effect is improved by 26%. Our scheme can not only obtain an ultra-colder molecular packet under the same molecular-beam parameters and deceleration conditions, but also be directly used to trap the slowed cold molecules after the deceleration without needing to use other techniques for molecular trapping.

Acta Physica Sinica•Jan 1, 2018•0 citations

Decelerating a pulsed subsonic molecular beam by a quasi-cw traveling optical lattice

Xiang Ji, Qi Zhou, Zhenxing Gu +1 more

We propose a promising scheme to realize the deceleration of a pulsed subsonic molecular beam by using a multistage optical Stark decelerator (i.e., a 1D quasi-cw traveling optical lattice), which is composed of two nearly counter-propagating, time-varying, red-detuned light fields with an intensity of ~10⁷Wcm⁻² and a fixed frequency difference between them. We also study the influence of the velocity reduced amount of the traveling lattice, the lattice power, the synchronous phase angle, the deceleration-stage number and the temporal profile of laser pulses on the molecular slowing results by using 3D Monte-Carlo method. Our study shows that the proposed decelerator cannot only be used to slow a pulsed subsonic beam from 240m/s to standstill, but also to obtain a cold molecular packet with a temperature of a few µK, and the corresponding fraction of cold molecules is 10⁻⁶-10⁻⁷, which strongly depends on the synchronous phase angle. And we also find that a pair of appropriate rising and falling times of laser pulses will lead to a better slowing effect than that produced by the top-hat temporal ones.

Optics Express•Mar 21, 2012•1 citation
This work presents the proposed schemes for decelerating cold molecules created in pulsed supersonic expansions using pulsed optical lattices. The first scheme relies on the application of a decelerating optical lattice with a dipole-potential well depth of approximately 1 K, created by rapidly chirping medium-intensity fields in the 10 W/cm/sup 2/ range. This scheme is an optical analog of the Start decelerator that has been successfully used to slow a range of polar molecules. A significant fraction (about 10%) of the very heavy I/sub 2 /molecules in an Ar buffer gas is shown to be slowed by using this method over sub-microsecond time scales. In the second technique, an optical lattice with larger well depth in the 100 K range travelling at half the supersonic beam velocity is used to trap a significant fraction of the cold, high-velocity molecules. This technique is developed based on the property of periodic motion of the trapped molecules in the optical lattice; the molecules reverse their initial (relative) velocities in the lattice reference frame after half a period. Using this method the cold molecules can be transferred from high speed to zero velocity on nanosecond time scales. As an example, 33% of a CO molecule beam (1 K) with a velocity of 230 m/s is slowed utilising optical intensities of less than 10/sup 12/ W/cm/sup 2/.
We investigate the deceleration and bunching of cold molecules in a pulsed supersonic jet using a far-off-resonant optical lattice traveling with a constant velocity. Using an analytical treatment, we show that by choosing the lattice velocity equal to half the supersonic beam velocity and by optimizing the pulse duration, a significant fraction $(\ensuremath{\sim}33%)$ of translationally cold (1 K) CO molecules from a supersonic molecular beam can be decelerated to zero velocity, and simultaneously bunched in velocity space. Due to the large difference of polarizability to mass ratio between the buffer gas and the CO molecules in the pulsed jet, the buffer gas can be precluded from the fraction of stationary molecules by choosing a suitable pulse duration. Furthermore, we find that spatial bunching within the optical lattice is induced and the position of the bunch within the lattice can be chosen by varying the lattice velocity.
We study the creation of stationary cold molecules by rapid deceleration of supersonically cooled molecules in a high-intensity pulsed optical lattice. Using the heavy molecule I2{\mathrm{I}}_{2}I2​ as an example we predict the evolution of the velocity distribution function of the ensemble during the deceleration period, and show that stationary cold molecules with temperatures below 1 K and densities of approximately ${10}^{12}{\mathrm{cm}}^{\ensuremath{-}3}$ can be produced over length scales of hundreds of micrometers on submicrosecond time scales.
The deceleration of molecules from cold molecular beams using electric and magnetic fields has become an important means for producing stationary, cold dipolar or paramagnetic molecular gases that can be trapped and potentially cooled to ultra-cold temperatures in the μK range. We report on a general scheme for the creation of cold molecules of essentially any type by deceleration of a cold molecular beam using intense optical fields. Deceleration of benzene molecules to zero velocity is achieved by utilizing a single half oscillation of the center-of-mass motion of the molecules within a moving optical lattice. The lattice traveling at half the speed of the molecular beam is created by the interference of two near-counter-propagating fields at different frequencies. We show that by rapidly switching on the optical lattice for approximately the time required for a half oscillation, a bunch of approximately 10 5 benzene molecules can be rapidly decelerated and brought to rest in the laboratory frame.
We propose a new scheme to realize a multistage optical Stark deceleration for a supersonic molecular beam using a time-varying red-detuned quasi-cw optical lattice with a length of up to 10 mm. We analyze the motion of the slowed molecules inside the optical decelerator, and study the dependences of the velocity of the slowed molecular packet on the synchronous phase angle and the number of the deceleration stages (i.e., the number of the optical-lattice cells) by using Monte-Carlo method. Our study shows that the proposed optical Stark decelerator cannot only efficiently slow a pulsed supersonic beam from 230 m/s to zero (standstill), but also obtain an ultracold molecular packet with a temperature of sub-mK due to bunching effect in the multistage optical Stark decelerator, which can be trapped in the optical lattice by rapidly turning off the modulation signal of the lattice. Also, we compare the decelerated results of our multistage optical Stark decelerator with a single-stage optical one, and find that our scheme cannot only obtain a colder molecular packet under the same molecular-beam parameters and deceleration conditions, but also be directly used to trap the slowed cold molecules after the deceleration, while don't need to use another molecular trap.
According to the optical Stark deceleration theory of using a stationary quasi-cw red-detuned optical lattice to slow and trap an arbitrary pulsed molecular beam, we propose a novel idea of using a modulated optical lattice instead of a stationary one to realize a multistage optical Stark deceleration. We analyze the motion of the decelerated molecules inside the optical decelerator, and study the dependence of the velocity of the decelerated molecular packet on the synchronous phase angle and the number of the deceleration stages (i.e. half the number of the optical-lattice cells) by using the Monte-Carlo method. The simulation results show that it takes longer time for the molecules to reach the detector as the number of the deceleration stages increases. The decelerated molecular wave packets are gradually separated from the large wave packets of the original molecular velocity distribution. And the higher the number of the deceleration stages, the lower the decelerated molecular speed is. In addition, we also study the influence of the initial phase angle of synchronous molecules under the same conditions. It is demonstrated that the higher the initial phase angle of synchronous molecules, the lower the decelerated molecular speed is and the smaller the number of molecules in the deceleration wave packet, so the phase space is compressed. The result also shows that the modulated optical Stark decelerator does not have the process of molecular free flight, and thus improving the efficiency of deceleration for molecules. The ultra-cold molecules can be trapped in the optical lattice by rapidly turning off the modulation signal of the lattice. Comparing with the previous scheme, the doubled number of the deceleration stages is reached in the same optical lattice length since a modulated optical lattice is used. For a length of optical lattice of 3.71 mm, theoretical simulation results demonstrate that the speed of methane molecules is decelerated from 280 m/s to 172 m/s. Comparing with the previous results from 280 m/s to 232 m/s, the deceleration effect is improved by 26%. Our scheme can not only obtain an ultra-colder molecular packet under the same molecular-beam parameters and deceleration conditions, but also be directly used to trap the slowed cold molecules after the deceleration without needing to use other techniques for molecular trapping.
We propose a promising scheme to realize the deceleration of a pulsed subsonic molecular beam by using a multistage optical Stark decelerator (i.e., a 1D quasi-cw traveling optical lattice), which is composed of two nearly counter-propagating, time-varying, red-detuned light fields with an intensity of ~10⁷Wcm⁻² and a fixed frequency difference between them. We also study the influence of the velocity reduced amount of the traveling lattice, the lattice power, the synchronous phase angle, the deceleration-stage number and the temporal profile of laser pulses on the molecular slowing results by using 3D Monte-Carlo method. Our study shows that the proposed decelerator cannot only be used to slow a pulsed subsonic beam from 240m/s to standstill, but also to obtain a cold molecular packet with a temperature of a few µK, and the corresponding fraction of cold molecules is 10⁻⁶-10⁻⁷, which strongly depends on the synchronous phase angle. And we also find that a pair of appropriate rising and falling times of laser pulses will lead to a better slowing effect than that produced by the top-hat temporal ones.