- (1) Aarhus University, grid.7048.b, AU
- (2) University of Otago, grid.29980.3a
- (3) Spanish Center for Pulsed Lasers, grid.494576.d
We investigate fluorescence detection using a standing wave of blue-detuned light of one or more atoms held in a deep, microscopic dipole trap. The blue-detuned standing wave realizes a Sisyphus laser cooling mechanism so that an atom can scatter many photons while remaining trapped. When imaging more than one atom, the blue detuning limits loss due to inelastic light-assisted collisions. Using this standing-wave probe beam, we demonstrate that we can count from 1 to the order of 100 atoms in the microtrap with sub-Poissonian precision.