  We demonstrate discrimination of ground-state hyperfine manifolds of a cesium
atom in an optical tweezer using a simple probe beam with 99.91(2)% detection
fidelity and 0.9(2)% detection-driven loss of bright state atoms. Our detection
infidelity of 0.09(2)% is an order of magnitude better than previously
published low-loss readout results for alkali-metal atoms in optical tweezers.
Our low atom loss and high-fidelity state detection eliminates the extra
depumping mechanism due to population transfer between excited-state sublevels
through V-type stimulated Raman transitions caused by the trap laser when the
probe laser is present. In this work, complex optical systems and stringent
vacuum pressures are not required.
