Sep 18 (Wed) @ 11:00am: "High Performance Quantum Dot Gain Devices for Heterogeneous Integration on Silicon Photonics," Chongxin (Tyler) Zhang, ECE PhD Defense

Zoom Meeting: https://ucsb.zoom.us/j/89319496510

Abstract

In the past decades, most telecom, datacom, and sensor systems have been developed based on discrete optical components. As the demand for data transfer is rapidly rising, the need to reduce cost, size, weight, and power consumption becomes more critical. Historically, photonic integrated circuits based on indium phosphide (InP) and silicon-on-insulator (SOI) have been widely utilized. However, the high cost of InP substrates and the lack of light sources for SOI silicon photonics (SiPh) limit scalability. Instead, the integration of III-V quantum dot (QD) gain on silicon is gaining attention for realizing efficient and robust on-chip light sources. Compared to the monolithic and hybrid integration methods, micro-transfer printing (MTP) offers advantages such as the potential for high-volume production and process maturity of III-V devices on native substrates, which could be leveraged for transfer of QD gain materials from III-V to SiPh wafers. Optical coupling approaches for MTP include evanescent or butt coupling. The latter takes advantage of the insensitivity to polarization, broad optical bandwidth, and the ability to support high optical power. Etched facet formation, however, including high quality etching and facet coating, remains a challenge.

This research focuses on the development of high-performance QD gain integration using butt-coupled MTP integration for SiPh. QD semiconductor optical amplifier (SOA) device design and fabrication process integration with MTP integration to for low-loss silicon nitride on silicon is discussed. A robust approach to characterize and calibrate deposited anti-reflection coatings on etched facets is developed demonstrating 0.6% reflectance. The etched facet lasers for transfer-printing deliver 90mW output power at room temperature, and the SOAs demonstrates >20dB gain and >15dBm saturation power.

Bio

Chongxin (Tyler) Zhang received his B.S. in Electronic Science and Technology from Xi’an Jiaotong University, and M.S. degree in Electrical and Computer Engineering from University of Michigan. He is currently pursuing his Ph.D. degree in the department of Electrical and Computer Engineering at University of California, Santa Barbara. His research focuses on the heterogeneous integration of high-performance quantum dot gain devices on silicon photonics.

Hosted by: Professor Jonathan Klamkin

Submitted by: Chongxin (Tyler) Zhang <chongxinzhang@ucsb.edu>