title: Phase noise analysis of a 10 Watt Yb-doped fibre amplifier seeded by a 1-Hz-linewidth laser.
abstract: We report a thorough analysis of the spectral properties of an ytterbium-doped fibre amplifier, seeded by a Nd:YAG laser, whose linewidth has been narrowed down to 1 Hz by locking the laser to an ultrastable reference cavity. We measured the phase noise contribution from the amplifier, showing that it does not depend on the amplification gain, nor on the seed laser linewidth. Moreover, the amplifier-induced phase noise does not affect the final linewidth, as verified by heterodyne linewidth measurement within the 0.2 Hz resolution bandwidth of our acquisition set-up. Preservation of spectral purity below Hz-level is promising for more demanding applications, from nonlinear optics to frequency/time-standard transfer over fibre links.
authors.affiliation: INO–CNR, Istituto Nazionale di Ottica, Sezione di Napoli, and LENS, European Laboratory for Nonlinear Spectroscopy, Via Campi Flegrei 34, I-80078 Pozzuoli (NA), Italy.
authors.forename: Iolanda
authors.initials: I
authors.lastname: Ricciardi
authors.forename: Simona
authors.initials: S
authors.lastname: Mosca
authors.forename: Pasquale
authors.initials: P
authors.lastname: Maddaloni
authors.forename: Luigi
authors.initials: L
authors.lastname: Santamaria
authors.forename: Maurizio
authors.initials: M
authors.lastname: De Rosa
authors.forename: Paolo
authors.initials: P
authors.lastname: De Natale
mesh_terms: D000669:Amplifiers, Electronic; D016477:Artifacts; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D053844:Lasers, Solid-State; D059629:Signal-To-Noise Ratio