Modelling Atom Optics

                 

Principal Investigator

Craig Savage

Department of Physics and Theoretical Physics

One of the goals of atom optics is the creation for atoms of efficient analogues of optical elements. Mirrors, lenses, and beamsplitters have been constructed. These elements might be combined into devices such as atomic interferometers.

Evanescent wave atomic mirrors have been realised in a number of experiments. Current experimental and theoretical work in the department is directed towards demonstrating an atomic beamsplitter based on diffraction from an evanescent wave grating.

We have developed a realistic computational model of diffraction of multi-level alkali atoms. The model is based on a first principles solution of the Schrodinger equation.

 
           

Projects

r62 - VPP

   
           
                 

   
                 

What are the results to date and the future of the work?

Our results have shown that control of the polarization of both laser beams is crucial in reflection grating atomic diffraction experiments. This was not previously known. Our model is currently being used in conjuction with the diffraction experiment in the department to identify suitable parameter regimes and interpret results.

What computational techniques are used?

We solve the single atom time-dependent Schrodinger equation from first principles. The internal atomic structure and its interaction with light is included. We make a minimum of assumptions which ensures a versatile and realistic model.

The solution is found by a split-operator method which reduces the problem to matrix multiplication and Fourier transforms, which vectorise well. A supercomputer is required to maximise the realism of our model. We must also examine a large number of cases to cover the uncertainties in experimental parameters.

Publications

Gordon, D., Savage C., Evanescent wave diffraction of multi-level atoms, Optics Communications, 130, 1996, 34.