Investigation On The Generation And Amplification Of Femtosecond Fiber Laser

Ultra-short pulse fiber laser has become one of the best candidate of the laser application market with its unique advantage.Its applications involve the medical,scientific research,military and industrial processes,and many other fields.Combining mode-locking technique with chirped pulse amplification technology and using them in the double cladding fiber or large mode field of photonic crystal fiber are advanced technology in the high average power femtosecond laser field.Combining mode-locking technique with master oscillator power amplification is one of the most effective technical solution in 1.5?m ultrashort pulse laser generation.This paper focuses on scientific research and the development of market demand and introduces our research work in high average power femtosecond Yb-doped fiber laser,ultrashort pulse Er-doped fiber laser and the dark solitons generation in fiber laser detailed.The main research contents and innovative results as follows:1.We design and set up an Yb-doped high power all normal dispersion mode-locked fiber lasers based on the nonlinear polarization evolution principle.At the pump power of 500 mW,stable mode-locking with repetition rate of 66 MHz,average power of 194 mW,spectrum width of 14 nm,and pulse width of 2 ps can be obtained.The pulse duration can be dechirped to 95 fs by grating pair compressor.2.We carried out the research on high average power femtosecond fiber laser based on chirp pulse amplification(CPA)technology.Using the self-similar pulse fiber laser as seed source and combining with the single mode fiber optic pulse broadening,we could obtain ultrashort pulse laser whose repetition rate is 75 MHz,the highest average power is 10 W after power preamplifier amplification and an energy main amplification.The dechirped pulse duration is as short as 108 fs after external compression.3.We carried out the research on the L-band all-fiber Er-doped fiber laser.By using the high doping concentration erbium-doped fiber gain,we could cut down the cavity length and improve the stability of the laser.The fiber laser can produce 152 mW output at the repetition rate of 37.8 MHz with pulse duration of 370 fs.4.Femtosecond Er-doped fiber amplifier equipment research:Using the Erbium-doped fiber oscillator based on NPR as seed source and applying master oscillation power amplification technology to dispersion management and power amplification.We construct a compact structure of femtosecond mode-locked erbium-doped optical fiber amplifier finally.Ultrashort laser pulse with repetition rate of 83 MHz,pulse width of 115 fs,the maximum output power of 211 mW is obtained.5.We have experimentally investigated various types of soliton generation of a dispersion management Yb-doped fiber laser.We use the transmission grating to manage the cavity dispersion precisely.The traditional bright solitons,dark-bright pairs and dark solitons were observed in the experiment.The pulse duration of the dark-bright solitons is 386 fs.