Professor Steven Koester named Optica Fellow

Professor Steven Koester was recently elevated to Fellow by Optica, formerly The Optical Society (OSA). He was cited for his "technical innovations in optoelectronic devices, particularly those involving group-IV and 2D-material-based photodetectors and optical modulators."

Koester’s contributions to the development of emerging group-IV and 2D-material based optoelectronic materials and devices have been game changers. His demonstration of ultra-high-speed germanium (Ge) photodetectors on silicon (Si), and the superior performance of receivers using these devices when integrated with CMOS amplifier circuits, has led to the development of Si-compatible Ge photodetectors used in commercial silicon photonic circuits.

His research has been significant in its demonstration that the performance of Ge photodetectors is comparable to that of detectors made from III-V materials. His work assessing the capabilities of these devices has been pivotal to the establishment of Ge as the material of choice for commercial integrated silicon photonic receivers used by semiconductor companies such as Luxtera, a Cisco subsidiary.

Koester has also made critical contributions to innovations in 2D material optoelectronic devices: he and collaborators at the University of Minnesota Twin Cities published theoretical predictions of the energy and high speed performance capabilities of waveguide-coupled graphene optical modulators; made the first-ever measurements of optical absorption in  graphene integrated on a silicon waveguide and the first demonstration of a waveguide-coupled black phosphorus photodetector. Koester’s other important work on 2D-material based optoelectronic devices include demonstrations of dual-mode photovoltaic/phototransistor devices in molybdenum disulfide, plasmonic light sources enabled by graphene, and biosensors using graphene-edge dielectrophoresis and fluorescence light  detection. This latter work was performed in collaboration professor Sang-Hyun Oh, who was also named an Optica Fellow this year. Koester’s work on 2D-material-based photonics has been impactful as well. His work on graphene optical modulators established the emerging field of graphene integrated photonics, which is currently being commercialized by several start-up companies in Europe, and his work on graphene-edge dielectrophoresis has broad implications for biosensing applications.

Besides Koester’s research contributions, he has made several and significant service contributions to the field of optoelectronic devices. He served on the technical program committee for the International Group-IV Photonics Conference in 2006 and 2008, and co-organized the Electrochemical Society meeting, “SiGe, Ge, and Related Compounds: Materials, Processing, and  Devices Symposium” from 2006-2012. He has served as a technical program vice-chair for the International SiGe Technology and Device Meeting in 2006, and as program chair in 2012. Koester has co-authored a chapter in a book on Ge photodetectors, Handbook of Silicon Photonics, CRC Press, 2013, and edited numerous conference proceedings volumes on SiGe technology.

Professor Steven Koester is the Russell J. Penrose Professor in Nanotechnology, and is the director of the Minnesota Nano Center. He was also named IEEE Fellow in 2017 for his contributions to group-IV electronic and photonic devices.