Self-probed ptychography from semiconductor high-harmonic generation.

We demonstrate a method to image an object using a self-probing approach based on semiconductor high-harmonic generation. On the one hand, ptychography enables high-resolution imaging from the coherent light diffracted by an object. On the other hand, high-harmonic generation from crystals is emerging as a new source of extreme-ultraviolet ultrafast coherent light.

Highly efficient few-mode spatial beam self-cleaning at 1.5µm.

We experimentally demonstrate that spatial beam self-cleaning can be highly efficient when obtained with a few-mode excitation in graded-index multimode optical fibers. By using 160 ps long, highly chirped (6 nm bandwidth at -3dB) optical pulses at 1562 nm, we demonstrate a one-decade reduction of the power threshold for spatial beam self-cleaning, with respect to previous experiments using pulses with laser wavelengths at 1030-1064 nm. Self-cleaned beams remain spatio-temporally stable for more than a decade of their peak power variation.

Author Correction: All semiconductor enhanced high-harmonic generation from a single nanostructured cone.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Generation of 35 kW peak power 80 fs pulses at 2.9 μm from a fully fusion-spliced fiber laser.

Tunable femtosecond light sources in the short wave and middle wave infrared regions are of utmost importance for various applications ranging from multiphoton microscopy, mid-infrared supercontinuum generation to high-harmonic generation. We report on an all-fusion-spliced fiber laser emitting 80 fs pulses up to 2.9 μm with 35 kW peak power.

All semiconductor enhanced high-harmonic generation from a single nanostructured cone.

The enhancement and control of non-linear phenomena at a nanometer scale has a wide range of applications in science and in industry. Among these phenomena, high-harmonic generation in solids is a recent focus of research to realize next generation petahertz optoelectronic devices or compact all solid state EUV sources. Here, we report on the realization of the first nanoscale high harmonic source.

Orbital angular momentum from semiconductor high-order harmonics.

Light beams carrying orbital angular momentum (OAM) have led to stunning applications in various fields from quantum information to microscopy. We examine OAM from the recently observed high-harmonic generation (HHG) in semiconductor crystals. HHG from solids could be a valuable approach for integrated high-flux short-wavelength coherent light sources.

[Limb-shaking transitory ischaemic attack in a patient with subocclusion of the internal carotid artery].

Described in the article is a clinical case report concerning symptomatic subocclusion of the internal carotid artery in a male patient with a rare variant of recurrent limb-shaking transitory ischaemic attacks (LS-TIA). The patient presented with a three-month history of episodes of involuntary jerky movements in his left hand. These episodes occurred invariably on assuming a vertical position.

Two-photon microscopy with a frequency-doubled fully fusion-spliced fiber laser at 1840 nm.

We introduce a fiber-based laser system providing 130 fs pulses with 3.5 nJ energy at 920 nm at a 43 MHz repetition rate and illustrate the potential of the source for two-photon excited fluorescence microscopy of living mouse brain. The laser source is based on frequency-doubling high-energy solitons generated and frequency-shifted to 1840 nm in large mode area fibers.

High-energy dissipative solitons generation from a large normal dispersion Er-fiber laser.

We report on a passively mode-locked erbium-doped fiber laser featuring a large normal dispersion and emitting high-energy dissipative solitons. Mode-locking is stabilized by the combined actions of a high nonlinearity amplitude modulator and a narrow band spectral filter. The laser routinely delivers highly chirped pulses with more than 38 nJ energy that can be compressed down to 700 fs duration using bulk gratings.

[Retrograde type A aortic dissection after endovascular repair of the thoracic artery].

Retrograde type A aortic dissection is a severe and prognostically unfavourable complication of endovascular repair of the thoracic aorta. The aim of the present article is to describe a clinical case report concerning a hybrid operative intervention for retrograde type A aortic dissection in a patient having endured two-stage endovascular repair of the thoracic artery.

Inner cladding microstructuration based on symmetry reduction for improvement of singlemode robustness in VLMA fiber.

Very large mode area, active optical fibers with a low high order mode content in the actively doped core region were designed by removing the inner cladding symmetry. The relevance of the numerical approach is demonstrated here by the investigation of a standard air-silica Large Pitch Fiber, used as a reference. A detailed study of all-solid structures is also performed.

High power all-fibered femtosecond master oscillator power amplifier at 1.56 μm.

Direct amplification of output from chirped pulse oscillator (CPO) to 3.3 W of average power (pulse energy of 118 nJ in 20 ps pulse duration before compression) was achieved in a properly designed cladding pumped large mode area Er-doped fiber. Various configurations of CPO cavity with different FWHM of output spectrum and pulse duration were investigated.

Very-large-mode-area photonic bandgap Bragg fiber polarizing in a wide spectral range.

A design of a polarizing all-glass Bragg fiber with a microstructure core has been proposed for the first time. This design provides suppression of high-order modes and of one of the polarization states of the fundamental mode. The polarizing fiber was fabricated by a new, simple method based on a combination of the modified chemical vapor deposition (MCVD) process and the rod-in-tube technique.

130 mW average power, 4.6 nJ pulse energy, 10.2 ps pulse duration from an Er3+ fiber oscillator passively mode locked by a resonant saturable absorber mirror.

An Er(3+) fiber laser passively mode locked by a resonant saturable absorber mirror achieves more than 130 mW average power at 1560 nm from a Fabry-Perot cavity. The pulsed regime is self-starting from the CW regime without any Q-switch transition. The output pulse has a duration of 10.

Management of the high-order mode content in large (40 microm) core photonic bandgap Bragg fiber laser.

Very large-mode-area Yb(3+)-doped single-mode photonic bandgap (PBG) Bragg fiber oscillators are considered. The transverse hole-burning effect is numerically modeled, which helps properly design the PBG cladding and the Yb(3+)-doped region for the high-order mode content to be carefully controlled. A ratio of the Yb(3+)-doped region diameter to the overall core diameter of 40% allows for single-mode emission, even for small spool diameters of 15 cm.

Polarization-maintaining photonic bandgap Bragg fiber.

The possibility of fabricating a polarization-maintaining Bragg fiber has been studied. It is shown that violation of the cylindrical symmetry of a Bragg mirror in most cases results in a sharp increase in optical loss, which is caused by resonance transmission through the Bragg mirror at wavelengths near the cutoffs of the modes of the high-index rings with a nonzero azimuthal index. It is shown that placing stress-applied parts or air holes inside the Bragg fiber core allows one to avoid this effect.

Single-mode all-silica photonic bandgap fiber with 20-microm mode-field diameter.

An all-silica photonic bandgap fiber with a cladding index difference of approximately 2 % and diameter-to-pitch ratio (d/wedge) of 0.12 was fabricated and studied. To our knowledge, this is the first report on the properties of photonic bandgap fiber with such a small d/wedge.

High-power photonic-bandgap fiber laser.

An original architecture of an active fiber allowing a nearly diffraction-limited beam to be produced is demonstrated. The active medium is a double-clad large-mode-area photonic-bandgap fiber consisting of a 10,000 ppm by weight Yb(3+)-doped core surrounded by an alternation of high- and low-index layers constituting a cylindrical photonic crystal. The periodic cladding allows the robust propagation of a approximately 200 microm(2) fundamental mode and efficiently discriminates against the high-order modes.