Ultra-High-Capacity Optical Communications and Networking: "Integrated photonic crystal/quantum dot chip for wavelength division multiplexed fiber optic transceivers"

University Of Southern California, Los Angeles CA

Investigators

Abstract

This proposal was submitted in response to the solicitation NSF 01-65 on "Ultra-High Capacity Optical Communications and Networking." Semiconductor fabrication technology has advanced to a state where revolutionary new devices can now be fabricated that bring new functionality and applications to fiber optic interconnects. Two of these new technologies, photonic crystals and self-organized quantum dots (QDs), enable a synergistic match of nanostructured materials that are particularly interesting. Photonic crystal defects enable ultra-small semiconductor microcavities with 3-dimensional mode confinement that intrinsically sets the wavelength of the light source. They also provide a mechanism for routing light signals on chip in sharp bends between elements, for example to multiplex the outputs of several laser sources into a single optical output. Because of these unique features, photonic crystals enable a new type of monolithicaliy integrated chip technology ideally suited for wavelength division multiplexing (WDM). This new chip technology offers revolutionary advances for low cost, high performance, ultra-small form factor transceivers for ultra-high bandwidth fiber optic communication. Such a WDM chip technology can easily provide single fiber bandwidth in excess of 100 GB/sec. Here we propose to demonstrate the multi-wavelength source for such a chip. We propose to design, and demonstrate a nanophotonic WDM source that is a multi-wavelength laser array in which each element of the array consists of coupled photonic crystal defect cavities emitting at a single wavelength with quantum dot active regions. This work relies on the design and nanofabrication of photonic crystals for the optical mode definition and the ability to define the output wavelength of an array element. It also relies on quantum dots for reducing or eliminating surface recombination and for eliminating the laser chirp. This WDM source is to be electrically pumped. Our program emphasizes the following technological developments 1) electrically pumped photonic crystal lasers 2) high efficiency photonic crystal lasers with quantum dot active regions and sampled- grating photonic crystal reflectors 3) edge-emitting multi-wavelength photonic crystal/quantum dot laser arrays