Research On Optical Arbitrary Waveform Measurement Techniques Of FROG Based On The PPLN

Optical arbitrary waveform generation(OAWG) technology for the generation of optical arbitrary waveforms takes an important role in many fields, such as of laser technology, high-speed optical communications applications, microwave photonics, high-quality sources generation and so on. Thus, the measurement technology of optical arbitrary waveform has also drawn great attention of scholars at home and abroad and has become an important research topic. Presently, the main measurement methods of arbitrary waveforms are dual quadrature spectral interferometry technique, Dual-comb electric-field cross-correlation technique and Frequency-resolved optical gating technique. In contrast, the FROG measuring method can realize the measurement of amplitude and phase of optical arbitrary waveforms and its device is simple, which is a kind of effective measuring method. Due to its large nonlinear optical coefficient, LiNbO3 crystal is the more sophisticated nonlinear material for non-linear optical devices. Periodically poled lithium niobate(PPLN) is a kind of "periodically poled" micro structure of LiNbO3 crystal. As an efficient quasi-phase-matched crystal, PPLN can change the wavelength of laser. Combining the advantages of the FROG measuring method and the PPLN waveguide, a FROG measurement scheme for optical arbitrary waveform based on the PPLN waveguide is proposed. The accureate measurement of both the amplitude and phase of optical arbitrary waveform are realized. In addition, the working performance of the proposed scheme is also deeply investigated. The main achievements and conclusions are listed as following:(1)Firstly, the study purpose and significance of the optical arbitrary waveform measurement technology are clarified. Then the research status of optical arbitrary waveform measurement technology is summarized. The preparation technology and the quasi-phase matching principle of the PPLN waveguide are finally introduced.(2) A X-FROG measurement scheme for optical arbitrary waveform based on PPLN is proposed. By using the SFG effect of the PPLN waveguide, combining with principal component generalized projects(PCGP) algorithm based on matrix, the theory model of the scheme is established.(3)The FROG measurement scheme for optical arbitrary waveform based on the PPLN waveguide is simulated and the accurate measurement of optical arbitrary waveform is realized. The impacts of the complexity of the optical arbitrary waveform, shape of the gate pulse, nonlinear interaction length and phase mismatch on the measurement accuracy are also investigated.(4) A new Blind-FROG measurement scheme for optical arbitrary waveform based on the PPLN waveguide is proposed. By using the SFG effect of the PPLN waveguide, combining with principal component generalized projects(PCGP) algorithm based on matrix, the theory model of the scheme is established. By using the software of Matlab, the proposed optical arbitrary waveform measurement Blind-FROG scheme using the PPLN waveguide is simulated and studied. In the numerical simulation, the measurement of intensity and phase of optical arbitrary waveform are both realized. For instance, the impacts of the complexity of the optical arbitrary waveform, phase mismatch on the measurement accuracy and the number of iterations are investigated.