Seminars 2019/2020

7th October 2019

Nonlinear Laser Dynamics - An Introduction

 
Date and TimeLocation

Laser dynamics describes the state of operation where a laser's output intensity is varying in time. Initially thought of as a nuisance, laser dynamics nowadays attracts a lot of attention as an enabling technology for future applications. Whether it's ultra-high-bandwidth telecommunications, highly sensitive measurement setups, or self-driving cars, laser dynamics has found its way into modern technology.

In this talk, I will give an introduction to laser dynamics, illuminating the theoretical backgrounds and fundamentals. Being a nonlinear system, lasers not only are integral parts of optoelectronic technology, but furthermore constitute testbeds for the study of nonlinear dynamics, including deterministic chaos. I will give a selection of modern applications based on laser dynamics and also give a glimpse into the mathematical beauty of nonlinear dynamics.

4pm, Monday,
7th October
2019
B10A,
Kane Building,
UCC 

16th September 2019

Ultrafast Carrier Interactions in Semiconductors and Gases: From Mode-locking in Semiconductor Disk Lasers to Kerr nonlinearity suppression in the Atmosphere  

Date and TimeLocation

Prof Jerome Moloney

Semiconductor disk lasers are ideal testbeds for studying strong departures of carriers (electrons and holes) from quasi-Fermi distributions. Carriers, optically-pumped into high momentum states, scatter into lower momentum ones and are extracted as photons near the lasing wavelength. High peak intensity femtosecond duration pulses burn deep kinetic holes in the carrier distributions – the latter are replenished through kinetic hole filling and subsequently cool (via phonons) to the lattice temperature.

In the extreme NLO limit, where the field coupling dominates the Coulomb potential, ultrashort pulses highly detuned from the semiconductor bandgap can expose dominant intraband interactions that can accelerate carriers across the full Brillouin zone (Bloch oscillations) and enhance harmonic generation relative to purely interband processes. Recent experiments with strong THz driving fields dramatically support this observation.

 

4pm, Monday,
16th September
2019
B10A,
Kane Building,
UCC 

Department of Physics

Roinn na Fisice

Room 213, 2nd floor, Dept. of Physics, University College Cork, Ireland,

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