QUANTUM GRATING REFLECTIVITY AND GRATING POLARITON LIFETIMES

An analysis of the optical properties of an array of quantum wires of cylindrical shape is presented. Effects of the electromagnetic couplin g between the wires are found to be given by additional energy shifts and modified oscillator strengths of the reflectivity peaks with respe ct to the single-wire exciton polariton ones previously calculated. Nu merical values for realistic structures show the importance of these e ffects. Changes of the lifetimes of the single-wire excitations produc ed by this electromagnetic coupling are also put into evidence. In par ticular, the short lifetimes of the two-dimensional exciton-polariton are recovered when the interwire distance D is smaller than the wavele ngth lambda of light. Stationary, or non-radiative electromagnetic mod es are also expected in this close-packed case. These radiative and no n-radiative modes therefore show some analogies with those found in tw o-dimensional systems such as quantum wells.