Jan 25 (Thu) @2:00pm: "Integrated Stress-Optic Silicon Nitride Photonics for Communications and Atomic Applications,” Jiawei Wang, ECE PhD, Defense

Date and Time
Henley Hall, Lecture Hall 1010

Zoom Meeting: https://ucsb.zoom.us/j/88437330805?pwd=UmZVdFZOemp5ODVpNVpwTThWQ0gxdz09


Modulation-based control and locking of lasers, filters and other photonic components is a ubiquitous function across many applications that span the visible to infrared, including atomic, molecular and optical (AMO), fiber communications, metrology, and microwave photonics. Today, modulators used to realize these control functions consist of high-power bulk-optic components for tuning, sideband modulation, and phase and frequency shifting. To enhance the power efficiency, scalability, and cost-effectiveness of these applications while reducing size and weight, it is imperative to implement modulation control functions in a low-loss, wafer-scale CMOS-compatible photonic integration platform. The silicon nitride integration platform has been successful at realizing low waveguide losses across the visible to infrared and components including high performance lasers, resonators and stabilization cavities. However, the advancement in integrating low-loss, low-power modulators into the silicon nitride platform has been constrained.

This research represents progress in integration of a piezo-electric (PZT, lead zirconate titanate) actuated micro-ring modulator on a fully-planar, wafer-scale silicon nitride platform. The PZT modulators maintain low optical losses for the silicon nitride waveguides designed at infrared and visible wavelengths, accompanied by moderate modulation bandwidth of tens of MHz and ultra-low power consumption down to tens of nW. Optical control applications have been demonstrated utilizing the developed PZT modulator for sideband modulation in a Pound-Drever Hall (PDH) lock loop for laser stabilization and as a laser carrier tracking filter. Subsequently, an AOM/EOM-free laser stabilization scheme is demonstrated unifying both functions through a single PZT modulator. This approach has the potential to pave the way for photonic integrated stabilized lasers, given the compatibility of the PZT modulator with both the integrated reference cavity and lasers. Furthermore, a symmetrically coupled three resonators photonic molecule is studied and its supermodes splitting can be fully controlled by the PZT actuators.


Jiawei Wang is a 6th year PhD student in Professor Daniel J. Blumenthal's Optical communication and Photonic integration group at University of California, Santa Barbara. His research focuses on silicon nitride photonic circuits integrated with piezoelectric material and stress-optic modulation for on-chip optical control applications. He received his B.Eng. degree in Electrical Engineering from Huazhong University of Science and Technology, China and M.S. in Electrical and Computer Engineering from University of California, Los Angeles in 2017.

Hosted by: Professor Daniel Blumenthal

Submitted by: Jiawei Wang <jiawei_wang@ucsb.edu>