Gabriele Bolognini | Searcharxiv

arXiv2024

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

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.

physics.atom-ph↗

arXiv2012

Distributed Raman optical amplification in phase coherent transfer of optical frequencies

We describe the application of Raman Optical-fiber Amplification (ROA) for the phase coherent transfer of optical frequencies in an optical fiber link. ROA uses the transmission fiber itself as a gain medium for bi-directional coherent amplification. In a test setup we evaluated the ROA in terms of on-off gain, signal-to-noise ratio, and phase noise added to the carrier. We transferred a laser frequency in a 200 km optical fiber link with an additional 16 dB fixed attenuator (equivalent to 275 km of fiber on a single span), and evaluated both co-propagating and counter-propagating amplification pump schemes, demonstrating nonlinear effects limiting the co-propagating pump configuration. The frequency at the remote end has a fractional frequency instability of 3e-19 over 1000 s with the optical fiber link noise compensation.

physics.optics↗