The Okawa Foundation for Information and Telecommunications has named Constance Chang-Hasnain, University of California, Berkeley as a 2018 recipient of the Okawa Prize. She is being honored for her “pioneering and outstanding research of VCSEL photonics through the development of their novel functions for optical communications and optical sensing,” Dr. Chang-Hasnain is the Whinnery Distinguished Chair Professor of Electrical Engineering and Computer Sciences, Associate Dean for Strategic Alliances, College of Engineering, and co-Director of the Tsinghua-Berkeley Shenzhen Institute.
Dr. Chang-Hasnain published the first comprehensive theoretical and experimental studies on VCSEL modal properties, which provided VCSEL design guidelines. Her fabrication method of using proton implantation for fabricating planar VCSEL for high speed operation has become an industry standard. Today’s dominant commercial transmitter for datacenter communications has its origins in her pioneer work on Gbps multi-mode (MM) VCSEL transmission using MM fiber. Her original concepts of VCSEL arrays paved the way for optical fiber short-wave division multiplexing (SWDM) systems and optical projectors in facial recognition applications.
By integration of Micro-Electro-Mechanical Systems (MEMS) and photonic systems, Dr. Chang-Hasnain invented a new class of wavelength-tunable laser design that can provide both a fast sweep rate and a wide range. Besides enabling wavelength division multiplexed (WDM) datacenter fiber communications, this body of has also impacted other applications, including swept-source coherent optical tomography for ophthalmology, dermatology, cardiology, and gastroenterology; biomedical and pharmaceutical analysis; and sensing applications.
Another invention of Dr. Chang-Hasnain is a new class of flat, ultra-thin optics, referred to as high-contrast gratings (HCG). This class of gratings can be an ultra broadband high reflectivity reflector, a high quality-factor resonator, as well as phase control elements. By replacing the traditional distributed Bragg reflector on a VCSEL with the HCG gratings, Dr. Chang-Hasnain greatly improved MEMS-VCSEL sweep range and speed, and demonstrated a continuously tunable, directly modulated tunable 1550-nm VCSEL for datacenter network, LIDAR (3D imaging) and fiber-to-the-home applications.
Dr. Chang-Hasnain has served different positions in the Optical Society of America (OSA), the IEEE Photonics Society and SPIE. She chaired many professional conferences including the 2018 International Nano-Opotelectronics Workshop, which she co-chaired with the other 2018 Okawa Prize recipient, Dr. Fumio Koyama. She has received numerous awards; for example, the Humboldt Research Award (2009), IEEE Sarnoff Award (2011), and UNESCO Medal for the Development of Nanoscience and Nanotechnologies (2015). In 2018, she was elected to the US National Academy of Engineering.