Purely gain-coupled distributed feedback laser via a bright optical lattice

We utilize degeneracy of Bragg resonance and the intersubband transitions in a quantum well bright optical lattice to propose a coherently induced purely gain-coupled distributed feedback laser. The optical lattice is generated via formation of periodic regions of resonant intersubband gain without inversion in the absence of any refractive index perturbation using a control laser field. We show that longitudinal mode intensity profile and standing wave effects of such an intrinsically single-mode intersubband laser can be coherently controlled. These features allow immunity against spatial hole burning and lasing when modal loss is higher than modal gain. (c) 2006 American Institute of Physics.