Quantum dot lattice and enhanced excitonic optical nonlinearity

We propose a concept of quantum dot lattice for enhancing the excitonic optical nonlinearity, especially its figures of merit. The most important aspect of the quantum dot lattice for enhancing the optical nonlinearity is the enlarged exciton coherence length due to the cooperation of a large number of quantum dots. The optical nonlinearity of the quantum dot lattice composed of typical semiconductor materials is estimated and an enhancement in the figures of merit of several orders of magnitude over the ever known values is predicted.