PARTIAL-TRANSFER ABSORPTION IMAGING OF 87Rb BOSE-EINSTEIN CONDENSATES

Abstract

We present the design, testing, and implementation of a minimally-destructive, partial-

transfer absorption imaging system. Partial-transfer absorption imaging in 87Rb utilizes

a microwave transition to transfer a fraction of the atoms in a Bose-Einstein condensate (BEC) prepared in the F = 1 hyperfine state into the F = 2 hyperfine state, where they can

be imaged on a cycling transition. The F = 1 and F = 2 hyperfine states are far apart

enough in frequency that the F = 1 BEC is essentially unaffected by the imaging probe

beam. The modulation transfer function, spot diagram, and point spread function for the

imaging optics are simulated and measured on a bench model. We demonstrate the use

of the imaging system, and we characterize the atom number and decay rate in a series of

images of a repeatedly imaged BEC as a function of one of the imaging parameters, the

microwave pulse time.