Our research focusses on analysing the non-linear dynamics of semiconductor lasers, thereby understanding and manipulating the instabilities that arise in technologically important laser systems and configurations.
There are three main areas of interest:
- Neuromorphic dynamics of semiconductor lasers
- Dynamics of quantum dot lasers
- Swept source lasers
Given the ubiquity of semiconductor lasers in technology, understanding the dynamical behaviour of these devices is crucial for applications. Semiconductor lasers also provide excellent playgrounds for researchers of nonlinear dynamics in general and coupled oscillators in particular. We study various configurations of semiconductor lasers including optical injection, mutual coupling, delayed feedback and mode-locking.
Stability diagram for optically injected quantum well laser. B. Kelleher, C. Bonatto, G. Huyet and S.P. Hegarty, Phys. Rev. E 83, 026207 (2011)
Neuromorphic photonics is an emerging field where photonic systems are used to mimic the behaviour of neurons. In particular, we study systems of coupled lasers and the emergence and control of excitable spiking regimes.
Experimentally triggered excitability in a quantum dot laser
Quantum Dot Lasers:
The non-linear dynamics of quantum-dot lasers has been a topic of great interest in recent years and in ongoing research. The localised quantum-dot states and the nonlinear charge-carrier scattering processes modify the laser dynamics compared to conventional laser devices. We analyse single-mode, multimode and mode-locked devices.
Coexistence of coherence (narrow distributions) and incoherence (broad distributions) in the frequency comb of a mode-locked quantum dot laser. E,A. Viktorov, T. Habruseva, S.P. Hegarty, G. Huyet, B. Kelleher, Phys. Tev. Lett. 112, 224101 (2014)
Swept Source Lasers:
Swept source lasers are devices typically used for Optical Coherence Tomography applications. A recent focus of the group has been in analysing the dynamics of such lasers including Fourier Domain Mode Locked Lasers and short cavity swept devices.
Real time evolution of the intensity, average frequency and optical spectrum of a short cavity swept laser. T.P. Butler, D. Goulding, S. Slepneva, B. O’Shaughnessy, S.P. Hegarty, G. Huyet and B. Kelleher, Optics Express 27, 7307 (2019).