title: Chirally-coupled-core Yb-fiber laser delivering 80-fs pulses with diffraction-limited beam quality warranted by a high-dispersion mirror based compressor.
abstract: We demonstrate a high-energy femtosecond laser system that incorporates two rapidly advancing technologies: chirally-coupled-core large-mode-area Yb-fiber to ensure fundamental-mode operation and high-dispersion mirrors to enable loss-free pulse compression while preserving the diffraction-limited beam quality. Mode-locking is initiated by a saturable absorber mirror and further pulse shortening is achieved by nonlinear polarization evolution. Centered at 1045 nm with 39-MHz repetition rate, the laser emits 25-nJ, positively chirped pulses with 970-mW average power. 6 bounces from double-chirped-mirrors compress these pulses down to 80 fs, close to their transform-limited duration. The loss-free compression gives rise to a diffraction-limited optical beam (M2 = 1.05).
authors.affiliation: Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139, USA.
authors.forename: Hung-Wen
authors.initials: HW
authors.lastname: Chen
authors.forename: Tom
authors.initials: T
authors.lastname: Sosnowski
authors.forename: Chi-Hung
authors.initials: CH
authors.lastname: Liu
authors.forename: Li-Jin
authors.initials: LJ
authors.lastname: Chen
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Birge
authors.forename: Almantas
authors.initials: A
authors.lastname: Galvanauskas
authors.forename: Franz X
authors.initials: FX
authors.lastname: Kärtner
authors.forename: Guoqing
authors.initials: G
authors.lastname: Chang