Optical trapping and cooling of $^{87}$Rb with a 1550 nm fiber laser

We have investigated optical trapping and cooling of $^{87}$Rb with a 1550nm single-frequency, fiber laser. We present a technique to map out the 3D spatial intensity profile of an optical dipole trap by imaging a background, untrapped cold atomic cloud. The 1550nm laser causes a strong AC Stark shift [1] of the excited state (5P$_{3/2}$) of $^{87}$Rb which we image by driving the D2 transition. Such Stark tomography allows us to use an untrapped cloud of $^{87}$Rb to characterize the potential trap depth, beam waist, trapping frequency, beam quality factor (M$^{2}$), and astigmatism of the trap beam. We also investigated schemes for all- optical evaporative cooling of trapped atoms to quantum degeneracy.