Controllable Storage Optical Memory

We propose a comprehensive research program for the realization of a novel all-optical memory with a storage length that can be adjusted via an external control. An all-optical memory is a critical building block for optical communications and signal processing. Such a device must have a storage that can be externally varied with a rapid response time. Thus far, there have been no such devices reported in spite of intense research in the field.

We propose to synthesize semiconductor quantum dot (QD) material in photonic crystals to achieve the adjustable storage. The idea centers on creating a medium that can reduce the group velocity of an optical signal beam by a variable amount. By controlling the slow-down factor, an optical memory with adjustable storage can be realized. Our goal is to achieve a 103-fold slow-down with minimum pulse dispersion at room temperature. The idea is based on recent breakthroughs of slow light in atomic gas cells. By creating a destructive interference between the electronic transitions of the atomic vapor and an external control laser, the real and imaginary parts of the refractive index of the medium was modified to result in a greatly reduced group velocity (e.g. 107 fold reduction)

Semiconductor-based devices that exhibit similar behavior would create an enormous impact. They are compact, mass manufacturable, facilitate monolithic integration, and consume lower power. Such devices can revolutionize optical communications by enabling new architectures. In addition, the various elements of this program will have a far-reaching impact; being fundamental, they can be applied to vast areas of optoelectronic devices and systems.