Interaction Between Bright And Dark Solitons In Silicon-based Optical Waveguides

Silicon-on-insulator(SOI)waveguide has strong nonlinear Kerr effect and other nonlinear optical characteristics,and has a strong constraint on the optical field.It has great research and development value in the fields of Integrated Optical Path and Optical Communication.Optical soliton communication has been widely concerned in high-speed,large capacity and long-distance All-optical Communication System because of the stability of soliton transmission in waveguide.In this thesis,the interaction between light and dark solitons propagating in SOI waveguides is numerically simulated by using the split-step Fourier transform and the nonlinear Schr?dinger equation(NLSE)satisfying the TE-mode and TM-mode directions in the SOI waveguide.The simulation shows that an increase in the relative polarisation angle of bright and dark solitons reduces the influence of bright solitons on dark solitons but increases the influence of dark solitons on bright solitons when the nonlinear effect is constant.At the appropriate polarisation angle,the dark soliton will show aquasi-soliton waveform under the influence of a bright soliton.When the power is similar,the interaction is most obvious.An increase in the bright soliton pulse width can increase its effective transmission distance and is greatly affected by dark solitons at short distances.A change in the dark soliton pulse width has little effect on the interaction.Changing the delay difference can change the position and peak of a quasi-soliton in a dark soliton.An appropriate delay difference can improve the effective transmission distance of the bright soliton and increase its stability in a short distance.A positive and negative chirp will affect the compression and broadening of bright solitons,and increase the effective transmission distance of bright solitons.The increase in the power and the pulse width of bright solitons will also affect the stable transmission of dark solitons,which will greatly deform the main pulse of dark solitons and aggravate the front oscillation of dark solitons.Negative chirps can promote the broadening and the consumption of bright solitons and reduce the influence on dark solitons.The increase in the power and the pulse width of negative chirp bright solitons can also increase the effective transmission distance of bright solitons,but these changes have less effect on dark solitons than positive chirp bright solitons,and the transmission of dark solitons is more stable.