Learning about lasers

The Department’s Professor Mike Adams explains: 'The research topic is “Injected Spin Lasers”, that is lasers whose output polarisation is controlled by the injection of spin-polarised electrons. Polarisation is a property of waves that describes the orientation of their oscillations.

Circular polarisation of laser radiation means that the tip of the electric field vector, at a fixed point in space, describes a circle as time progresses. Circular polarisation is referred to as right or left, depending on the direction in which the electric field vector rotates. An electron has one of two types of spin: spin up or spin down. In a spin-injected laser, spin down electrons couple to right circularly polarised radiation, whilst spin up electrons couple to left circularly polarised radiation, thus allowing us to control the output polarisation of the laser.'

'This research comes within the general topic of “spintronics”, which is the focus of major research worldwide aimed chiefly at using the spin of electrons to indicate the ones and zeros of binary computing, but there is little effort associated with spin-polarised light sources. This inter-disciplinary project is aimed at understanding the dynamics of spin lasers and covers advanced physics concepts such as chaos and instabilities, as well as optoelectronic components and sub-systems used in telecommunications engineering.'

EU Marie Curie Fellowships support the training and mobility of researchers, whilst promoting excellence in European research.