High Contrast Grating VCSELs for Optical Communications and 3D Sensing
Vertical cavity surface emitting lasers (VCSELs) are low-cost enabling laser sources for many applications including optical communications, 3D sensing and optical imaging. In this talk, speaker will review Berxel’s recent advances and commercialization of high-speed 106 Gbps PAM4 VCSELs for datacom applications and high-power conversion efficiency VCSEL arrays for 3D sensing applications.
A VCSEL typically consists of two distributed Bragg reflectors (DBRs) as the top and bottom mirrors. A DBR is comprised of many tens of layers of epitaxy layers with alternating refractive indecies and hence very thick. The thick top DBR makes it difficult to control the emission mode structure. Since 2004, her research group invented a new class of planar optics using near-wavelength dielectric structures, known as high contrast metastructures (HCM). Many extraordinary properties can be designed top-down based for integrated optics on a GaAs or silicon substrate. The one-dimensional version, a single layer high index contrast near-wavelength gratings (HCG), has been used to replace the hundred-layered DBR in a VCSEL structure.
Speaker will review recent results of HCG-VCSELs. With a fixed, high selection ratio in polarization, a novel structure light 3D sensor with high depth accuracy in scenes with multiple reflecting surfaces is shown. It is shown that HCG VCSEL exhibit fewer modes and can enable 3~5 times transmission distance over OM3 multimode fibers for 106G PAM4 modulation signal. Finally, speaker will also discuss future prospects for advanced applications.
Who Should Attend
Prof Connie J. Chang-Hasnain
Chairperson, Berxel Photonics Co. Ltd.
Prof Connie Chang-Hasnain is the Chairperson of Berxel Photonics Co. Ltd. and Whinnery Chair Professor Emerita at the University of California Berkeley. She is member of the US National Academy of Engineering and National Academy of Inventors.
Prof Chang-Hasnain was Associate Dean of College of Engineering (2014-2019), Chair of the Nanoscale Science and Engineering Graduate Group at UC Berkeley (2006-2017), and the founding Co-Director of Tsinghua Berkeley Shenzhen Institute (2015-2020).
Prof Chang-Hasnain pioneered the first planar VCSEL structure using proton implantation, first MEMS-VCSEL for wavelength tuning, and the first 1000-element VCSEL arrays for 3D imaging. Prof. Chang-Hasnain has been honored with many awards including the Okawa Prize (2018), UNESCO Medal For the Development of Nanoscience and Nanotechnologies (2015), IEEE David Sarnoff Award (2011), and the OSA Nick Holonyak Jr. Award (2007). She was the Editor-in-Chief of Journal of Lightwave Technology 2007-2012. She was the 2021 President of Optica (formerly known as OSA).