The Research Of Adiabatic Soliton Compression Technology

Ultrashort optical pulse has important applications in optical communications,military,industrial,and etc.Optical pulse compression technology is one of the main ways to generate ultrashort pulse.To achieve high-quality compression of picosecond pulse is the current research hotspot and difficulty.This paper mainly focuses on studying adiabatic soliton compression technology of picosecond pulse.The main contents are as follows:1.Adiabatic soliton compression(ASC)of picosecond pulses based on dispersion decreasing fibers(DDFs).The ASC processes in DDFs with different dispersion decreasing curves including hyperbola,linearity,cosine,and exponent,have been simulated and compared,respectively.It is found that hyperbolic and exponential DDFs are suitable for adiabatic soliton compression of picosecond pulses.The fundamental soliton pulse with width of 12.5 ps has been compressed adiabatically using hyperbolic DDF.The width of output pulse is only 1.95 ps and the compression factor is 6.4.At the same time,the pedestal energy is 10.24%.When we use exponential DDF to compress the same fundamental soliton pulse,the width,compression factor,and pedestal energy of output pulse are 2.98 ps,4.2,and 4.01%,respectively.2.Adiabatic soliton compression of picosecond pulses based on the nonlinearity increasing fibers(NIFs)has been studied.The ASC processes in NIFs with different nonlinearity increasing curves including hyperbola,linearity,cosine,and exponent,have been simulated,respectively.The ASC scheme suitable for picosecond pulses is achieved.The fundamental soliton pulse with width of 12.5 ps has been compressed adiabatically using linear and exponential NIFs.The width of output pulse is 1.61 ps when the length of NIF equals to 2DL.The compression factor is 7.76 and the pedestal energy is 9.4%.When we use hyperbolic NIF with length of 4DL to compress the same fundamental soliton pulse,the width,compression factor,and pedestal energy of output pulse are 2.2 ps,5.69,and 4.29%,respectively.3.The ASC scheme based on DDF has been optimized concerning peak power,effective amplification factor and fiber loss.A pulse with width of 6.25 ps,peak power of 1.2112 W,and single pulse energy of 8.586 pJ,has been compressed adiabatically into 830 fs.The compression factor is 7.53 and the pedestal energy is 4.44%.The adiabatic compression scheme suitable for picosecond pulse with larger width is proposed,which relies on increasing the peak power and the initial GVD value of DDF.By increasing the effective amplification factor of the exponential DDF,the fundamental soliton pulse with width of 12.5 ps has been compressed adiabatically into 1.32 ps.The compression factor and pedestal energy of the output pulse are 9.48 and 3.68%,respectively.4.The propagation and output characteristics of the fundamental soliton pulse in low doped erbium doped fiber amplifier(LEDFA)have been simulated and analyzed.It is found that pulse propagating in the LEDFAs with enough low gain coefficients will be compressed adiabatically due to the interaction of dispersion and nonlinear effects.A novel ASC scheme based on quasi-distributed amplification is studied.The fundamental soliton pulse with width of 10.1ps has been compressed into 2.6 ps experimentally.The compression factor is 3.9 and the pedestal energy is close to zero.