Engineered nanophotonic Raman amplifiers and lasers

University Of Texas At Arlington, Arlington TX

Investigators

Abstract

Abstract title: Engineered nanoscale optical amplifiers and lasers Nontechnical: Silicon photonics is presently among the most active fields of research and development in optical science and technology. Importantly, silicon photonics is compatible with modern electronics technology on which everyday integrated circuit chips for computers and communications are based. Motivating this project, there is a need for useful and economic means for silicon-based light generation for silicon photonics technology. We plan to fill this void by engaging a unique optical resonance effect on nanostructured silicon films to generate light. Thus, we propose to develop new active devices, namely lasers and amplifiers, enabled by this fundamental effect. This can lead to new types of lasers serving as sources for silicon photonic chips as well as amplifiers for enhanced detection of incoming signals carried by light pulses as used in internet data transmission. Integrated photonic systems are expected to increase transmission and processing rates in optical communications. Under the project, we will evaluate the utility of fundamental photonic resonance effects, thus far not applied for this purpose, to enable advanced light generation in silicon. The project provides excellent analytical and experimental experience for graduate students thus supporting the development of the next-generation workforce in photonics technology. If successful, the project will led to innovative light generation and amplification concepts with substantial economic benefits and societal value. Technical: The objective of this research is to design, fabricate and characterize a new class of active nanophotonic guided-mode resonance elements. Specifically, we will investigate Raman amplifiers and lasers enabled by this effect. The research is motivated by the fact that Raman emission can be enhanced to high levels with these high-quality-factor resonance effects that are attainable in nanopatterned silicon films. We present preliminary device designs where the spectral placement of the pump and Raman lasing wavelengths achieves the proper Stokes-Raman shift in silicon. Here, the pump and lasing resonances have large quality factors with corresponding high Raman gain which is dominated by the product of the two factors. These elements will be fashioned as periodic nanostructures in the silicon-on-quartz and the silicon-on-insulator materials systems. We investigate fundamental aspects of the resonance interaction in these devices by computing emission spectra and attendant internal photonic field distributions including local field strengths. The fabricated devices will be characterized by electron-beam and atomic-force microscopy and their detailed spectral properties will be measured. The efficiency of the Stokes-Raman emission, including gain relative to pump, will be quantified relative to device architecture and input pump configuration. This project undertakes fundamental nanophotonic device research that is transformative, if successful, in view of potential applications in silicon photonics.