Guillaume Machinet

High-energy femtosecond photonic crystal fiber laser

We report the generation of high-energy high-peak power pulses in an all-normal dispersion fiber laser featuring large-mode-area photonic crystal fibers. The self-starting chirped-pulse fiber oscillator delivers 11 W of average power at 15.5 MHz repetition rate, resulting in 710 nJ of pulse energy. The output pulses are dechirped outside the cavity from 7 ps to nearly transform-limited duration of 300 fs, leading to pulse peak powers as high as 1.9 MW. Numerical simulations reveal that pulse shaping is dominated by the amplitude modulation and spectral filtering provided by a resonant semiconductor saturable absorber.

High-brightness fiber laser-pumped 68 fs-2.3 W Kerr-lens mode-locked Yb:CaF2 oscillator.

By using a high-brightness fiber pump laser, we demonstrate a pure Kerr-lens mode-locked (ML) Yb:CaF(2) oscillator. The laser delivers 68 fs pulses with 2.3 W average power at 73 MHz repetition rate and an optical-to-optical efficiency of 33% is achieved. To the best of our knowledge, this is the first demonstration of Kerr-lens mode-locking in Yb:CaF(2). Incidentally, we report here the highest average power ever achieved for a sub-100-fs active Kerr-lens ML Yb-bulk oscillator.

High-energy femtosecond fiber laser at 976 nm

We report on a passively mode-locked fiber laser emitting around 976nm. The self-starting mode locking is achieved in an unidirectional ring cavity by means of nonlinear polarization evolution. Stable single-pulse operation is observed for 480mW of average output power. This all-normal dispersion laser generates naturally chirped pulses with 1ps duration. The repetition rate is 40.6MHz, resulting in 12nJ pulse energy. External compression using bulk grating shortens the pulse duration down to 286fs.

Mode-locked 0.5 μJ fiber laser at 976 nm.

We report on high-energy femtosecond pulse generation from an ytterbium-doped rod-type fiber oscillator emitting around 976 nm. Self-starting and stable single-pulse operation are demonstrated with 4.2 W of average output power at a repetition rate of 8.4 MHz. The resulting energy level reaches 0.5 μJ. Because of the all-normal dispersion of the laser cavity, output pulses are naturally chirped with a duration of 14 ps. External compression using diffraction gratings shortens the pulse duration down to 460 fs.

Nonlinear compression of high energy fiber amplifier pulses in air-filled hypocycloid-core Kagome fiber

We report on the generation of 34 fs and 50 µJ pulses from a high energy fiber amplifier system with nonlinear compression in an air-filled hypocycloid-core Kagome fiber. The unique properties of such fibers allow bridging the gap between solid core fibers-based and hollow capillary-based post-compression setups, thereby operating with pulse energies obtained with current state-of-the-art fiber systems. The overall transmission of the compression setup is over 70%. Together with Yb-doped fiber amplifier technologies, Kagome fibers therefore appear as a promising tool for efficient generation of pulses with durations below 50 fs, energies ranging from 10 to several hundreds of µJ, and high average powers.

Sub-50 fs, Kerr-lens mode-locked Yb:CaF2 laser oscillator delivering up to 2.7 W

By means of a high-brightness optical pumping scheme with a fiber laser, we demonstrate Kerr-lens mode locking (KLM) with an Yb:CaF2 laser crystal. Stable 48 fs pulses are produced at an average power of 2.7 W.

Femtosecond Microjoule-Class Ytterbium Fiber Lasers

We report the generation of 830 nJ energy from a mode-locked all-normal dispersion fiber laser featuring large-mode-area photonic crystal fibers. After external compression, 550 fs pulses with 1.2 MW peak power are demonstrated.

Kerr lens mode-locking of Yb:CaF2

Through high-brightness optical pumping with a fiber laser, we demonstrate a soft-aperture Kerr lens modelocked (KLM) operation in a Yb:CaF2 crystal. Stable 117 fs pulses are producing at an average power of 560 mW.

Industry-grade 100-fs high energy Yb-doped amplifier with 3 colours

Femtosecond lasers have entered a significant number of industrial applications thanks to their unique properties in laser-matter interaction. One of the most popular sectors is the semiconductor and consumer electronics industry with its specific requirements of machining brittle or dielectric materials. In this dynamic industry, new material combinations emerge that can contain organic components and tend to require more and more sophisticated lasers with extremely short pulse duration of ∼100fs and flexible emission wavelengths.

High energy and high average power optical fiber ultrafast beam delivery and compression

We report on fiber delivery of ultrafast lasers. We demonstrate propagation of 500 fs, 1 mJ pulses over a distance of 10 m. We also report 100W average power transmission, and sub-50 fs pulse compression.