Optical Stark Deceleration Of Neutral Molecules From Supersonic Expansion With A Rotating Laser Beam

In the late of 20^th century,scientific researchers showed strong interest in the study of cold atoms and their efforts were rewarded with great success.Later,they turned their eyes to cold molecules,which might possess new physical or chemical properties due to their complex structure.Over the past decades,a lot of efforts have been dedicated to the production and manipulation of cold molecules with a number of methods being proposed and demonstrated.Each method has its own advantages and disadvantages,and new efforts for more general and versatile methods have never stopped.This thesis proposes and theoretically studies a versatile scheme for optical deceleration of molecular beams from supersonic expansion with a rotating laser beam.A potential application of the scheme is also briefly introduced.Some background knowledge is first reviewed with its focus on the production and storage of cold molecules.Next,the interactions between molecules and external electrical or optical fields are introduced.The energy shifts of ND₃ molecules in the external electric field are numerically calculated as an example.Then,a versatile scheme for optical deceleration of molecular beams is proposed.The dynamic behavior of decelerating ND₃ molecules inside the rotating laser beam is theoretically investigated and their trajectories are numerically simulated using Monte-Carlo method.The spatial and velocity distributions of the decelerated molecular beam are analyzed.The scheme can be conveniently incorporated into a torus of electrostatic quadrupole and form an opto-electrostatic storage ring for cold molecules.