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

Exact solution to the steady-state dynamics of a periodically modulated resonator

“…Generating such a profile can be beneficial for, e.g., optical clock distribution 27,28 or optical sampling. 29 To achieve the target transmission, we perform an optimization seeking to maximize the overlap between the CM-computed and the target transmission. We defineT t,n as the normalized Fourier components of the target transmission andT n as the normalized components computed through Eq.…”

A Chirp-z-Transform-Based Software Synchronization Method for Optical Performance Monitoring

“…All-optical sampling has proven to be powerful for real-time system optimization and signal monitoring [1]- [3]. Among the schemes to realize real-time performance monitoring, the asynchronous optical sampling scheme utilizing software-based synchronization has the advantage that neither a clock recovery circuit nor an externally synchronized sampling clock source is necessary.…”

Optical sampling of ultrahigh bitrate signals using highly nonlinear chalcogenide planar waveguides or tapered fibers

“…The nonlinear optical gates, forming the central part of the optical sampling system, can be classified according to the nonlinear process or according to the nonlinear medium that is being used. 1 One class of nonlinear optical gates, forming the central part of the optical sampling system, makes use of sum frequency generation or difference frequency generation originating from the second-order susceptibility χ (2) in nonlinear crystals, such as KTiOPO 4 (KTP) 2 or periodically poled LiNbO 3 (PPLN). 3 Another class makes use of cross-phase modulation (XPM) or four-wave mixing (FWM) that results from the third-order susceptibility χ (3) , in semiconductor optical amplifiers (SOAs) 4 or in optical fibers.…”

“…In recent years, optical sampling has emerged as a technique to perform time-resolved measurements of optical data signals at high data rates with a bandwidth that cannot be reached by conventional photodetectors and oscilloscopes. 1 In an optical sampling system, the optical signal is sampled in the optical domain by a nonlinear optical sampling gate before the resulting samples are converted to an electrical signal. This avoids the need for high bandwidth electronics if the optical sampling gate is operated with a modest repetition frequency.…”