Functional Photonic Circuits Based on Semiconductor Quantum Templates in Quantum Well Structures: Processing-Free Monolithic Integration

We propose and numerically demonstrate operation of a processing-free functional photonic integrated circuit based on a semiconductor quantum template. This template combines monolayer engineering of the well/barrier interfaces in quantum-well structures with their coherent nonlinear effects to spatially form desired patterns of refractive index, gain and absorption without any need for top-down processes such as lithography, etching, postprocessing epitaxial overgrowth, etc. As an example, we investigate an integrated circuit that includes a distributed feedback laser and a multitask functional section that can act as an ultra-fast attenuator, modulator or amplifier on demand. The distributed feedback laser is based on gain-without inversion to overcome various losses and induce single mode operation. The photonic circuit proposed in this paper is optically activated and holds the promise of highly functional multicomponent integrated photonic circuits fabricated in a single epitaxial growth.