The Experimental Study On The Nonlinear Polarization Rotation Lock Mode Laser

By ultrashort laser pulses ultrafast photonics technology,the human into a new world of space and time:Femtosecond laser provides a light probe with a time resolution of up to 10-15 seconds,it makes it possible for humans to understand the structure of atoms and molecules and their transient superfast motion.It is well known that development in any field requires the development of corresponding measurement methods and technologies.In the field of optical communication,the measurement and analysis of ultra-high speed optical signals is an urgent problem to be solved in the current broadband communication network.Ultra-wideband optical sampling oscilloscope is the test equipment for the research and development of ultra-high speed optical fiber communication equipment,system and network,it can only take samples of periodic pulses or random pulse signals of more than one time.The main reason for this limitation is that the sampling source of this oscilloscope is subcutaneous second pulse laser.In order to measure the shorter pulse,the development of the fractional domain broadband optical signal analyzer with the method of decreasing frequency coherent optical sampling is of great significance.In this paper,the sampling pulse laser is studied by means of experiment.The nonlinear polarization rotary lock mode fiber laser is a kind of passive mode-locked laser.It has the same advantages and passive mode-locked lasers,these advantages are compact structure,good stability,price is low wait for an advantage,and it can achieve pattern locking without any active components.The main research of this paper is how to improve the beam quality of the nonlinear polarization rotating lock mode fiber laser and reduce the volume of the laser,which are designed to provide the sampling light source for the new broadband optical signal analyzer.The main work of this paper is as follows:1)The traditional soliton lock mode fiber laser based on the nonlinear polarization rotation effect is built.The whole operation of optical pulse in resonator cavity and the process of locking die are introduced in detail.In the end,the laser achieved a stable locking mode,and the optical pulse signal of the repeated frequency at 29.7MHz was obtained,the demand of sampling pulsed laser is first satisfied in the requirement of repeated frequency.Then the system was tested for a series of long and short time stability.2)Some defects in the experimental scheme of traditional lock mode fiber laser are improved.The experiment platform of the optical fiber laser experiment platform and the display width pulse lock mode fiber laser experiment platform are built by adding the method of dispersion management.The laser's main components are integrated into a blue box of200mm*120mm*40mm,and the miniaturization of the laser is realized.The paper analyses the results of two experimental schemes,and summarizes the advantages and disadvantages of the optical fiber laser and the display width pulse lock mode fiber laser.3)Through the analysis of the results of three experimental schemes and the analysis of the requirements in practical application,the amplification spectrum experiment of the amplifying pulse locking fiber laser is selected in the end.In the amplification system,with limited volume requirements and limited pump power requirements,the system succeeded in amplifying the signal light by 21 times,and then by expanding the spectrum,the pulse width was the super-short pulse light of 20fs.The basic realization of the sampling pulse laser is required.