Study On Tunable Optical Delay Line Based On Four-wave Mixing

Tunable optical time delay line has many important applications in the field ofoptical communications, optical coherence tomography system and phased-array radarfield of microwave photonics，which makes it attracts a great deal of research interest.Recently, although the optical time delay line technology has made great progress, butit cannot meet the requirements of modern ultra-high speed optical communicationsystem.Tunable optical time delay line with high tuning ability and wide bandwidthbased on wavelength conversion and dispersion medium is a key technology ofall-optical high-speed communication network.The presented dissertation focuses onthe tunable optical time delay technology based on four wave mixing wavelengthconversion in highly nonlinear fiber (HNLF) and semiconductor optical amplifier(SOA), and the main contents are as follows:1. The research background and significance of tunable optical time delay linetechnology, as well as the technology based on optical fiber itself, based on the slowlight generation and based on the wavelength conversion combining dispersion in thefiber are introduced and analyzed in this paper.2. Various technologies of wavelength conversion are analyzed; The derivation of fourwave mixing technology and effect of the phase matching are presented. The delaycharacteristics of different frequencies propagating in dispersion medium are analyzedtheoritically3. The technology of wavelength conversion based on HNLF is analyzed theoretically.Simulations of factors affecting wavelength conversion efficiency, such as frequencyshift, pump power, are performed. At the same time, the tunable optical time delaylines based on8km single mode fiber and3.88km dispersion compensation fiber withtuning range of300ps~1ns and1ns~3ns, respectively, are obtained.4. The technology of wavelength conversion based on SOA is analyzed theoretically.And factors affecting wavelength conversion efficiency, such as cavity-length,injection current of SOA and wavelength difference between signal and pump aresimulated. At last, the tunable optical time delay lines based on single mode fiber anddispersion compensation fiber are obtained, with tuning range of270ps~1500ps and 700ps~3.4ns respectively.