Julien Javaloyes

How Laser Localized Structures evolve out of Passive Mode-Locking

We investigate the relationship between passive mode-locking and the formation of temporal localized structures in the output of a laser, allowing for individual pulse addressing and arbitrary low repetition rates.

Electrical addressing and temporal tweezing of localized pulses in passively mode-locked semiconductor lasers

This work presents an overview of a combined experimental and theoretical analysis on the manipulation of temporal localized structures (LSs) found in passively Vertical-Cavity Surface-Emitting Lasers coupled to resonant saturable absorber mirrors. We show that the pumping current is a convenient parameter for manipulating the temporal Localized Structures, also called localized pulses. While short electrical pulses can be used for writing and erasing individual LSs, we demonstrate that a current modulation introduces a temporally evolving parameter landscape allowing to control the position and the dynamics of LSs. We show that the localized pulses drifting speed in this landscape depends almost exclusively on the local parameter value instead of depending on the landscape gradient, as shown in quasi-instantaneous media. This experimental observation is theoretically explained by the causal response time of the semiconductor carriers that occurs on an finite timescale and breaks the parity invariance along the cavity, thus leading to a new paradigm for temporal tweezing of localized pulses. Different modulation waveforms are applied for describing exhaustively this paradigm. Starting from a generic model of passive mode-locking based upon delay differential equations, we deduce the effective equations of motion for these LSs in a time-dependent current landscape.

Topological Dissipative Solitons in Semiconductor Lasers

We analyze the formation of non dispersive solitary waves along the propagation dimension of a ring semiconductor laser with coherent forcing. We measure their phase dynamics and show that they can host a topological charge.

Modelling strategies for semiconductor ring lasers

We have analyzed experimentally and theoretically the modal properties of a semiconductor ring laser and the wavelength jumps that occur in connection with directional switching above threshold. A transfer matrix analysis allow us to explain the transfer function measurements when amplified spontaneous emission in the cavity is accounted for. Moreover the transfer matrix analysis permits to determine the threshold condition for the laser modes, which split in two branches due to the symmetry breaking imposed by the output coupler and output waveguides. The wavelength jumps displayed by the device above threshold are interpreted with the frequency splitting and threshold difference between these two branches of solutions, together with the redshift of the material gain.