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.'