All-fiber, near-infrared, laser system at 780nm for atom cooling

Abstract: One of the prominent platforms for quantum technologies, cold atoms require reliable laser systems. We present the design, implementation, and characterization of a simple, compact, and economical laser system at 780 nm, entirely based on fiber components. Two semiconductor lasers at 1560 nm are amplified in a single Erbium-doped fiber amplifier and frequency-doubled in a periodically-poled lithium niobate crystal. We characterize the amplitude noise and the linewidths of the lasers, as well as the SHG efficiency. With a rms relative amplitude noise of 3$\times$10$^{-4}$ at 1 s and linewidths below 1 MHz, our system is suitable for cooling and trapping of Rb atoms.