Antonio Pérez-Serrano (IFISC, Palma de Mallorca, Spain)

Exploring laser dynamics using a travelling wave model

A Travelling Wave Model (TWM) is a semi-classical approach to laser dynamics based on Partial Differential Equations (PDEs). It describes the dynamics of the different laser longitudinal modes retaining spatial effects. This approach presents some advantages, it can be easily modified to describe different laser cavities and different active media, and it naturally allows exploring multi-mode dynamics.

In the first part of the talk, I will present a TWM for a two-level atom medium. In this case computational tools have been developed to find their stationary solutions and to perform the linear stability analysis of these solutions. This analysis is very general and can be exported to other system based on PDEs. Using this model, multimode dynamics [1] and wavelength multistability [2] have been investigated in ring lasers. The results show that the wavelength of emission of these lasers can be selected by injection of an external field in agreement with experimental results. The results also show that wavelength multistability is not found in Fabry-Pérot lasers due to their high degree of spatial hole burning.

The second part of the talk will be devoted to Semiconductor Ring Lasers (SRLs). First, I will briefly discuss the modal properties of SRL real devices consisting of a ring cavity and coupled waveguides for the injection and extraction of light [3]. The results show that the impact of the composite cavity is noticeable in the cold cavity modes and the behavior of these lasers. Secondly, I will discuss about wavelength multistability in SRLs with the TWM which have been modified to take into account the semiconductor material. Finally, I will show an application of the TWM to obtain the L-I curve of a new laser device, the semiconductor snail laser [4].

[1] Pérez-Serrano et al. Physical Review A 81, 043817 (2010).
[2] Pérez-Serrano et al. Optics Express 19, 3284 (2011).
[3] Furst et al. Applied Physics Letters 93, 251109 (2008).
[4] Strain et al. Applied Physics Letters 96, 121105 (2010).