His research has focused on optical fiber communications including optical devices and systems. He has performed record-breaking optical transmission experiments at single-channel rates and demonstrated the first terabit transmission in 1996. During his career, he has investigated coherent detection, chromatic-dispersion compensation techniques, parametric optical signal processing and system impacts of fiber nonlinearities. Currently, Gnauck is involved in the study of wavelength-division-multiplexed (WDM) systems with single-channel rates of 100 Gb/s or higher. Gnauck has authored more than 250 journal and conference papers and holds over 29 patents in optical communications. He was elected as a Fellow to The Optical Society in 2004 for his demonstration of new optical transmission technologies. He was named an IEEE Fellow in 2009 and a member of the National Academy of Engineering in 2012. He served as an associate editor for IEEE Photonics Technology Letters from 2000 to 2009 and on the Optical Fiber Communications Conference technical subcommittee in 2000, 2001 and 2003 before chairing the subcommittee in 2004. In 2003, he received the Paul Foreman Team Engineering Excellence award for his numerous achievements in the development of high-speed, ultra-high-capacity lightwave systems, including the first demonstration of a Terabit/s system. He received the 2016 John Tyndall Award “for sustained pioneering research contributions that drove commercialization of high-speed, high-capacity lightwave communication systems.”