Neodymium Doped Double Clad Fiber Laser And Its Experimental Study Intracavity Frequency Doubling

From the first laser was successfully developed in the60’s of last century, because of its own superiority the fiber laser was widely used in the fields of fibre-optical communication, laser ranging, industrial processing and manufacturing, radar, military and national defense and construction, material handling, imaging, medicine,and so on.The domestic research of the high-power neodymium-doped fiber laser,especially intracavity frequency doublingis not enough.Therefore,this paper has analysed and discussed detailly on the aspects.and has achieved the output of the fundamental frequency laser and the second harmonic light.based on a lot of theoretical analysis and experimental research.The main content of this paer is:1. In this chapter we have summarized the development history of the domestic and foreign of the fiber laser and the Nd3+-doped fiber laser,and have discussed the fiber laser’s classification,advantages and applications.2. In this chapter we have discussed spectral speciality and energy level structure of the Nd:galass,then the operating principle and its key technology,that is cladding-pumped coupling technique,of the Nd+-doped fiber lase have been discussed brieflyly too. Finally,we have gaven an detailed analysis and discussion of the absorption characterristic of different cald shapes.3. In this chapter we have discussed the output characteristic,system design of the Nd3+-doped fiber fundamental fequency laser and the design of the second harmonic system. The output characteristic of the Nd3+-doped fiber on060nm was analysed in theory,and we determined the optimum fiber length in the pumping of808nm through simulation.Then we proved the lens coupling parameters buying in our experiment are to meet the request by using the ABCD matrix conversion.Finally, we simply analysed the frequency-doubling theory and phase-matching techinique to determine the frequency-doubling crystal.and made a preliminary design for the fundamental frequency laser system and the frequency-doubling system in our experiment.4.In this part,we using the LD pumped Nd3+-doped double-clad fiber realised several results that the coupling efficiency is80%-90%, optical conversion efficiency is33%, and continuous output is more than6W; in addition, on the result we operating the intracavity frequency-doubling achieved continuous output of green laser whose frequency-doubling efficiency is to18%,and its power exceeding1W.Then we analysed the experimental results,and proved the feasibility of intracavity ferequency doubling,giving some recommendations.