Semiconductor Fano Lasers

Abstract

In this paper, a new type of semiconductor laser based on Fano interference is described. One of the laser mirrors relies on the interference between the continuum of waveguide modes and a side-coupled nanocavity, leading to a narrow-band mirror that provides the Fano laser with unique characteristics. In addition to being truly single-mode, the laser can be modulated through the mirror at frequencies far exceeding the relaxation oscillation resonance. Furthermore, nonlinearities in the nanocavity can be used to implement a saturable mirror, leading to passive pulse generation with repetition frequencies in the gigahertz range. This paper reviews the theory of Fano lasers and the current experimental status. Experimentally, the Fano laser concept is demonstrated using a photonic crystal platform with quantum dot active material. Both continuous wave operation and self-pulsing is observed for optically pumped lasers operating at room temperature.