RII Track-4: NSF: Development of Semiconductor Lasers and Passive Devices on a Single Sapphire Platform for Integrated Microwave Photonics

University Of Arkansas, Fayetteville AR

Investigators

Abstract

The goal of this project is to develop a new sapphire platform for integrated microwave photonics (IMWP) technology, which transfers wireless signal processing and transmission challenges from the electronic to the photonic domain, could provide a wealth of new opportunities to achieve higher data communication rate. Sapphire platform features: (1) more favorable for the integration of excellent laser materials due to a closely matched coefficient of thermal expansion, and (2) attainable ultra-low-loss waveguides using silicon nitride technology. This NSF EPSCoR RII Track-4 project provides a fellowship to an Associate Professor and a graduate student at the University of Arkansas to visit the University of Texas at Arlington, aiming to establish a strong research collaboration that would support the long-term research goal to advance sapphire based IMWP technology. This work lays the foundation to investigate the feasibility of obtaining a complete set of high-performance optical components heterogeneously integrated on a single sapphire platform. If successful, the new sapphire platform would have tremendous applications in defense systems, such as Radar signal processing, and numerous civilian applications, such as 5G system, cellular, and medical imaging systems. In addition to the involvement of graduate and undergraduate students, the principal investigator recruits students from a local HBCU. The vision of this project is to leverage a new material system to enable heterogeneous integration of active and passive optoelectronics components, for microwave photonics, on a single chip. The motivation lies in the feasibility of sapphire for a fully integrated solution to include a complete set of components with light source, modulator, light detection, waveguides, couplers, resonators, CMOS control circuit, Silicon on Sapphire (SOS) circuit all-in-one sapphire platform to achieve high-performance low-cost mixed-signal optical links. The proposed sapphire platform utilizes the mature SOS CMOS and RF high frequency circuit technology featuring low power consumption. The sapphire platform has the (1) inability to conduct current thereby reducing parasitics; (2) sufficient optical index contrast resulting in low optical power loss; and (3) very uniquely, an excellent thermal expansion coefficient match to many III-V materials for high operating reliability. The research goal focuses on the development of sapphire based lasers and passive device building blocks including waveguides (straight and bend), splitters, couplers, and ring resonators. The research objectives are: (1) obtain the high performance III-V lasers on sapphire substrate via the development of wafer-to-wafer covalent bonding technology; (2) develop the low loss waveguide using the newly designed silicon nitride on sapphire technology; and (3) develop the resonators, couplers, etc. to obtain a set of passive devices. The proposed sapphire-based technology offers the promise of reduced size weight and power (SWaP) at a very low cost when manufactured in a foundry. This has the potential to benefit many applications in Radar signal processing, 5G system, satellite communications, and medical imaging systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.