Supercontinuum Generation Based On Short Pulse Of Dissipative Soliton

The top spectrum of dissipative soliton is flat,and the pulse energy is high.Experiments have found that it is difficult for dissipative soliton to generate pulse splitting in polarization maintaining fiber,and they have extremely strong stability.This article studies the generation of supercontinuum based on dissipative soliton short pulse,and analyzes the output spectrum and power characteristics.The main research content is as follows:1.Build a passive mode-locked fiber laser based on nonlinear polarization rotation to obtain dissipative soliton and bound state pulse by adjusting the polarization controller.Then,use a hydrogen oxygen flame taper machine to taper the highly nonlinear fiber,the core diameter of the fiber is 9 um becomes 6 um.The cladding diameter also decreases accordingly.Finally,the pulse of amplifying was injected into taper high nonlinear fiber to achieve switchable supercontinuum output.Using dissipative soliton as the seed source,the supercontinuum covers a range of 1200-2200 nm,with a maximum 20 d B bandwidth of375 nm and an average output power of 22 m W.Using bound state pulse as the seed source,the supercontinuum covers a range of 1600-1870 nm,with a maximum 20 d B bandwidth of135 nm and an average output power of 10 m W.2.By using two sections of fibers with opposite velocity dispersion values,the intracavity dispersion is close to zero,and the wave-free splitting pulse and dissipative soliton switching output are realized.The maximum pulse energy of dissipative soliton is 0.82 n J,and the pulse energy output by wave-free splitting pulse can reach 3.89 n J,which is 5 times the energy of dissipative soliton pulse.The supercontinuum generated by dissipative soliton has a maximum coverage range of 1400-2000 nm,20d B bandwidth of 310.3nm,and maximum average output power of 69 m W.The supercontinuum generated by wave-free splitting pulse has a maximum coverage range of 1200-2000 nm,20d B bandwidth of 426.4nm,and maximum average output power of 203 m W.3.Study the transmission characteristics of solitons in polarization maintaining fiber.Due to the mismatch in refractive index between the fast and slow axes of the polarization maintaining fiber,dissipative soliton will generate two coherent pulses through the polarization maintaining fiber,resulting in spectral modulation.The length of the polarization maintaining fiber is 12 m,the modulation period is 0.36 nm,and the pulse interval is 14 ps.The modulation period is inversely proportional to the length of the polarization maintaining fiber,and the pulse interval is directly proportional to the length of the polarization maintaining fiber.As the length of the polarization maintaining fiber increases,the modulation depth increases.Injecting conventional soliton into a 12 m polarization maintaining fiber,as the pump power increases,3,4,5,and 6 solitons appear in the time domain.Continuing to increase the pump power to 750 m W,a maximum of 11 solitons are observed.After calculation,the single pulse energy of dissipative soliton increases from20.4p J to 40.7p J.However,the single pulse energy of conventional soliton decreases from29.3p J to 13.7p J.Compared with conventional soliton,dissipative soliton have stronger stability and higher pulse energy in polarization maintaining fiber.The experiment found that although multiple pulses based on dissipative soliton can generate supercontinuum,the coverage range of supercontinuum is narrow..