1-THz bandwidth C- and L-band optical sampling with a bit rate agile timebase

A fast optical sampling system operating over a wide range of wavelengths and modulation bit rates is needed for characterizing high-speed communications signals. In this letter, a 1-THz bandwidth optical sampling system using sum frequency generation with a 780-nm sampling pulse is demonstrated. This covers the C- and L-bands with no wavelength holes near the sampling wavelength. A novel electrical/optical sampling scheme is used for the timebase to precisely measure the arrival of each optical sample relative to a 9-45 GHz electrical clock reference, covering bit rates of 9-320 Gb/s with low jitter.