Compact direct space-to-time pulse shaping with a phase-only spatial light modulator

A very compact and innovative pulse shaper is proposed and demonstrated. The standard architecture for pulse shaping that is composed of diffraction gratings associated with an amplitude-phase spatial light modulator (SLM) is replaced by a single phase-only SLM. It acts as a pulse stretcher and as an amplitude and phase modulator at the same time. Preliminary experiments demonstrate the accurate control of amplitude and phase of shaped pulses.     

Interactions of Type II vectorial spatial solitary waves in materials with quadratic non-linearity

We present analytical, numerical and experimental results of the interactions between Type II vectorial spatial solitary waves (QSSW) in second-order non-linear media. We show that the outcome of the interaction can be changed from beam coalescence to steering, crossing or repulsion through a non-coherent control (i.e. the control does not rely on the relative phase between the interacting QSSW). We also provide experimental evidence that both quasi-elastic and inelastic collision between QSSW are feasible in second order non-linear media, depending on the relative velocity of the interacting QSSW. We determine (analytically, numerically and experimentally) the critical transverse velocity for elastic collision to be observed, when the fundamental frequency component of the two interacting beams are orthogonally polarized at the input face of the non-linear crystal.     

Passive phase locking of an array of four fiber amplifiers by an all-optical feedback loop

We report the passive phase locking of an array of four fiber amplifiers in a unidirectional ring cavity. The feedback loop consists of a single-mode fiber that filters intracavity the far-field pattern of the four emitted beams. The pointing of the laser output can be managed by the intracavity filtering.     

Phase-locked supermode emissions from a dual multicore fiber laser

We report on a fiber laser configuration, emitting two phase-locked and single mode beams at the output of two multicore fibers. The passive technique is based both on the selective excitation of the only in-phase supermodes of the multicore fibers and on an intra-cavity angular filtering of the emitted beams to provide phase control. As a proof of principle, we experimentally demonstrate the coherent combining of the fundamental in-phase supermodes of two parallel 7-cores fibers.     

Tunable high-repetition-rate fiber laser for the generation of pulse trains and packets

We report on a mode-locked erbium-doped fiber laser suited to the generation of high-repetition-rate pulse trains or packets. The two-arm interferometer resonator performs a spectral filtering leading to the emission of short pulse packets with a high repetition rate, adjustable up to 200 GHz. A continuous pulse train with a repetition rate of up to 6.9 GHz was obtained by adding a recirculation loop inside the cavity to fill the spaces between all pulse packets.     

Quasi-Gaussian beam from a multicore fibre laser by phase locking of supermodes

We present a new cavity design for controlling the spatial quality of the beam delivered by a fibre laser including a multicore fibre. A quasi Gaussian profile is produced at the 7-core fibre output involving self-imaging effects in the multicore fibre and spatial filtering. Numerical and experimental investigations analyse the spatial and spectral characteristics of the multicore fibre laser.     

Highly efficient phase locking of four diode pumped Nd:YAG laser beams

We describe the mutual phase-locking of four Nd:YAG beams longitudinally end-pumped by four fiber-coupled diode lasers. Mutual phase-locking is performed by two types of diffractive components located inside a telescopic Fabry–Perot resonator. The control of the phase-locking is shown and the different spatial eigenmodes connected with the pumping geometry in the resonator are theoretically and experimentally studied. 1.2 W is obtained in a single mode stable pattern with 30% optical-to-optical conversion efficiency in the continuous wave regime.     

Collisions between type II two-dimensional quadratic solitons

We report experimental and numerical results that describe collisions between two-dimensional type II quadratic solitons excited in a KTP crystal by fundamental waves of orthogonal polarization. Our results provide experimental evidence of the possibility of both inelastic collision (when two quadratic solitons merge at input into a single soliton at output) and quasi-elastic collision.