Font Size: a A A

Research On High Repetition Rate Passively Mode-locked Fiber Laser

Posted on:2017-03-11Degree:DoctorType:Dissertation
Country:ChinaCandidate:S TaoFull Text:PDF
Abstract/Summary:PDF Full Text Request
Ultra-short pulse with a high repetition rate plays a very important role in the science research and industrial production.Passively mode-locked fiber laser can overcome the disadvantage of wide pulse width, narrow spectrum width and poor time stability in actively mode-locked fiber laser.Passively mode-locked fiber laser offer a better performance in producing stable pulse trains and wide spectrum due to the nonlinear effects and adaptive effect of the cavity. In this thesis, the novel high repetition ratepassively mode-locking fiber lasers are investigated, including high order passively harmonic mode-locked fiber laser inanomalous dispersionregion, high fundamental repetition rate passively mode-locked fiber laser, passively mode-locked fiber laser with a composite cavity structure, and hybrid type of passively and actively mode-locked fiber laser with a broad spectrum.The major results in the thesis are obtained as follows.1、we have systematically investigated the principle of harmonic mode-locking and the factors that influence the order of the harmonic mode-locking in anomalous dispersion region.During the experiment we find that cavity dispersion and nonlinearity play an very important role in producing high order passive H-ML. By reducing the cavity dispersion and increasing cavity nonlinearity,we have achieved a ultral high repetition rate of 22.132GHz,2192nd harmonic mode-locking.The pump power is greatly reduced compared with the previous work.2、 By using a novel integrated device OIM in a passively mode-locked fiber laser, which greatly shortens the cavity length,we obtain a fundamentally mode-locking with the repetition rate up to 100MHzat 1.5um,the pulse duration is 217fs with a SNR higher than 50dB.3、We have investigatethe influence of the cavity parameter on the repetition rate and stability of the mode-locked pulse in a composite cavity structure mode-lock fiber laser.By optimizing the cavity parameter, we obtain a 800MHz,46th harmonic mode-locking, The SMSR is higher than 45dB,the pulse train has a high stability and low time jitter.4、We put forward a method to broaden the spectral width in an active-passive mode-locked fiber laser.With a high nonlinear effect the unstability caused by relaxation oscillation,super-mode noise and amplitude fluctuation disappear.In the experiment we successfully broaden the spectrum to 4.084nm,this result is 100 times wider than the original spectrum of 0.047nm.The innovative work and results in this thesis are as follows:1、By reducing the cavity dispersion and increasing cavity nonlinearity,we have achieved 2192nd harmonic mode-locking.The repetition rate of the mode-locked pulse train breaks through more than 20 GHz.2、By using a novel integrated device OIM in a passively mode-locked fiber laser we obtain a high repetition rate fundamentally femtosecond mode-locked pulse train at 1.5um.3、By optimizing the cavity parameter, we obtain a stable 800MHz composite structure cavity mode-locked pulse train.4、By increasing cavity nonlinearity in a active-passive mode-locked fiber laser,we successfullybroden the spectrum width.
Keywords/Search Tags:Fiber laser, Passively mode-locked laser, High repetition rate, Ultra-short pulse
PDF Full Text Request
Related items