LIGHT SOURCE AND DEVICE

PROBLEM TO BE SOLVED: To provide a light source suitable for display and/or illumination.SOLUTION: A light source includes a heterostructure including semiconductor layers. The heterostructure forms a waveguide between a first end and a second end. The heterostructure includes a plurality of layers and includes an optically active zone 2 formed by the plurality of layers. The optically active zone is capable of emitting light guided by the waveguide. At least two different radiative transitions are excitable in the optical active by an electrical current between a p-side electrode and an n-side electrode. Transition energies of the at least two different radiative transitions correspond to wavelengths in the visible part of the optical spectrum. The light source further includes means for preventing reflections of light from the waveguide by at least one of the first end and the second end back into the waveguide.