Joel R. Buckley

Self-Similar Evolution of Parabolic Pulses in a Laser

Self-similar propagation of ultrashort, parabolic pulses in a laser resonator is observed theoretically and experimentally. This constitutes a new type of pulse shaping in mode-locked lasers: in contrast to the well-known static (solitonlike) and breathing (dispersion-managed soliton) pulse evolutions, asymptotic solutions to the nonlinear wave equation that governs pulse propagation in most of the laser cavity are observed. Stable self-similar pulses exist with energies much greater than can be tolerated in solitonlike pulse shaping, and this has implications for practical lasers.

Femtosecond fiber lasers with pulse energies above 10?nJ

A series of experiments aimed at determining the maximum pulse energy that can be produced by a femtosecond fiber laser is reported. Exploiting modes of pulse propagation that avoid wave breaking in a Yb fiber laser allows pulse energies up to 14 nJ to be achieved. The pulses can be dechirped to sub-100-fs duration to produce peak powers that reach 100 kW. The limitations to the maximum pulse energy are discussed.

Generation of 50-fs, 5-nJ pulses at 1.03 μm from a wave-breaking-free fiber laser

We report the generation of 6-nJ chirped pulses from a mode-locked Yb fiber laser at 1.03 μm . A linear anomalous-dispersion segment suppresses wave-breaking effects of solitonlike pulse shaping at high energies. The dechirped pulse duration is 50 fs, and the energy is 5 nJ. This laser produces twice the pulse energy and average power, and approximately five times the peak power, of the previous best mode-locked fiber laser. It is to our knowledge the first fiber laser that directly offers performance similar to that of solid-state lasers such as Ti:sapphire.

Generation of ten-cycle pulses from an ytterbium fiber laser with cubic phase compensation

We demonstrate the use of a prism-grating sequence to reduce third-order dispersion inside a mode-locked Yb fiber laser. This laser generates pulses as short as 33 fs with extremely clean temporal and spectral profiles. Nanojoule pulse energies are possible.

Stabilization of high-energy femtosecond ytterbium fiber lasers by use of a frequency filter

The performance of a femtosecond Yb fiber laser is investigated in the limit of high pulse energy (>10 nJ) and short pulse duration (<100 fs). By reducing the strength of nonlinear polarization rotation and introducing amplitude modulation through an intracavity frequency filter, pulses with unprecedented peak powers can be generated. The laser emits stable 13 nJ pulses that are dechirped to 55 fs duration and are capable of providing 130 kW peak power.

Practical all-fiber source of high-power, 120-fs pulses at 1 μm

Amplification of femtosecond pulses at 1.03 micrometre in a standard Yb-doped single-mode fiber is reported. A pulse energy of 8 nJ and an average power of 400 mW are obtained, limited by available pump power. To our knowledge these are the highest pulse energy and average power obtained from an integrated, single-mode fiber amplifier. After dechirping, 120-fs, 6-nJ pulses are obtained. A practical fiber-based source with performance comparable with that of a bulk solid-state laser is thus demonstrated, and scaling to substantially higher powers will be possible.

Self-similar evolution of parabolic pulses in a fiber laser

A femtosecond fiber laser supporting self-similarly propagating parabolic pulses is demonstrated theoretically and experimentally. In addition to constituting another example of self-similarity, this new pulse shaping mechanism in principle allows scaling to unprecendented pulse energies.

All-Normal-Dispersion Femtosecond Fiber Laser

We demonstrate a modelocked ytterbium (Yb)-doped fiber laser that is designed to have strong pulse-shaping based on spectral filtering of a highly-chirped pulse in the cavity. This laser generates femtosecond pulses without a dispersive delay line or anomalous dispersion in the cavity. Pulses as short as 170 fs, with pulse energy up to 3 nJ, are produced.

Generation of 10-Cycle Pulses from a Yb Fiber Laser Using Cubic Phase Compensation

We demonstrate the use of a prism-grating sequence to reduce third-order dispersion inside a Yb fiber oscillator. Pulses as short as 33-fs, the shortest from a fiber laser, can be generated with extremely clean profiles.

Period-doubling route to multiple-pulsing in femtosecond fiber lasers

An analytical model, compatible with large changes, describes soliton mode-locking in fiber lasers. The predicted period-doubling route to multiple-pulsing is confirmed experimentally. The simple model explains the remarkable observation that chaos does not follow period-doubling.