Study Of Broadband Light Source Centered At 1.55μm Through QPM-OPG

In this thesis, a new-style broadband light source was theoretically analyzed and the pump source of it, 946nm Nd:YAG quasi-three-level laser system was investigated roundly and thoroughly.Broadband light source has very extensive and important applications in many fields such as optical communication, optical sensing, biomedicine and spectral analysis. Quasi-phase-match(QPM) is one of the new methods that could ennable broadband source. The principle taken use in this project is the retracing behaviors of parametric oscillation tuning curve. When pumping with proper wavelength the output wavelength is very sensitive to the variation of poled period at the break point in the QPM tuning curve, which is close to infinity, that is, that poled period corresponds to a certain range of output wavelengths all of that can approximately meet the phase match condition.In this paper, the research work and findings are as follows:The developement of broadband source. Familiar examples were enumerated, as well as the advantages, disadvantages and application of them. The new broadband source based on QPM was introduced.Quasi-phase-match theory was discussed in depth. QPM coupled equations was educed from Maxwell equation. Introduction of the advantages of QPM and the key component, periodically poled crystal.The theory of QPM-OPG broadband source was explored in detail. The pumping wavelength and specific poled period was accurately chosen by numerical calculation.The pumping source of QPM-OPG, LD longitudinally pumped 946nm Nd:YAG laser system was theoretically studied and the threshold ,output power and slope efficient were numerically simulated. The conclusions of Optimal crystal length and optimal mode overlap were derived from the computer simulationDemonstration of 946nm laser was concluded. A maximum CW output power of 1.4W and slope efficient of 18.4% was got. Some prospective work was put forward, such as passively Q-switched operation of 946nm laser and pumping PPLN crystal with it to get QPM-OPG broadband source. There following innovation points:Firtly, we start our analysis from the concept of phase match width and calculated the bandwidth of the QPM-OPG broadband source according as it.Secondly, we use first-order collinear QPM-OPG to produce broadband source centered at 1.55μm. And the determination of optimal pump wavelengthThirdly, the development of 946nm Nd:YAG laser and pumping PPLN with it...