Optical: Ultrafast all-optical switches, modulators, and wavelength converters based on intersubband transitions for Tb/s operation

Cornell University, Ithaca NY

Investigators

Abstract

0334986 Rana At data rates exceeding 100 Gb/s it is desirable to perform pulse processing functions entirely in the optical domain. The research proposed here aims to develop ultrafast all-optical switches, modulators, wavelength converters, and devices for all-optical pulse retiming, reshaping, and reamplification (3R generation) capable of performing at speeds close to 1 Tb/s by using intersubband transitions in semiconductor quantum wells. Intersubband relaxation times of electrons in semiconductor quantum wells are around 1 ps. Such short relaxation times allow for the realization of ultrafast optical devices. The research proposed here will develop devices for all-optical signal processing operating at 1.55 mm using GaN/AlGaN/AlN multiple quantum wells. The devices proposed here offer the potential of switching speeds close to 1 Tb/s and require pulse energies as low as 100 fJ. All-optical switching, modulation, and wavelength conversion by cross-loss modulation (XLM) in intersubband saturable absorbers, and all-optical 3R generation by differential cross-phase modulation (XPM) in intersubband optical amplifiers will be explored. The proposed research covers all aspects of device design, material growth, device fabrication, and device characterization. A successful demonstration of the devices proposed in this research will create a new technology platform for ultrafast optoelectronic devices operating at 1.55 mm. The proposed research will contribute to the development of other ultrafast intersubband optoelectronic devices operating at 1.55 mm, such as lasers, detectors, electro-absorption modulators, and fast saturable absorbers for modelocked lasers. Graduate and undergraduate students involved in this project will get training in cutting edge optoelectronics. In addition, the broader impact of this work will be in the development of course curricula that will synthesize various perspectives of electrical engineering, quantum engineering, optics, and solid state physics at the undergraduate and graduate levels.