Optical sampling techniques

Abstract

The optical sampling technique is a novel method to perform time-resolved measurements of optical data signals at high bit rates with a bandwidth that cannot be reached by conventional photodetectors and oscilloscopes. The chapter reviews the techniques that are used in optical sampling systems to perform the ultrafast sampling of the signal under investigation. In addition to the various nonlinear materials and effects used for the optical sampling gates and pulse sources, the realized optical sampling systems also differ in the way, in which the system is synchronized to the data signal. Systems have been reported using synchronous, random and software synchronized configurations. Applications of optical sampling systems include high bit rate waveform and eye diagram measurements, measurements of constellation diagrams of phase modulated data signals, time-resolved measurements of the state-of-polarization as well as investigations of fiber transmission impairments.