Research On Supercontinuum Generation Technology Based On Planar Waveguide

Nonlinear optics is a branch of modern optics.It mainly studies the nonlinear effects and applications of light in nonlinear media.The development of laser technology provides a high intensity,highly coherent light source for nonlinear optical research.Supercontinuum(SC)is an important part of nonlinear optics.The nonlinear media that produce SC include fiber,photonic crystal fiber and waveguide.In this paper,the nonlinear medium with SC is studied and the structure of planar waveguide is analyzed and designed.Based on the fourth order Runge-Kutta method for solving partial differential equations,a large range of SC spectra are generated by simulation.In this paper,the research progress of SC spectrum at home and abroad is investigated.It is found that the limitation of spectrum broadening in optical fiber and photonic crystal fiber is limited,the spectrum broadening range is small,and the optical fiber and photonic crystal grating need long transmission distance,which is not conducive to the integrated development of optical devices.Secondly,the structure model of the waveguide is introduced.The importance of the low order mode transmission is analyzed.The structure characteristics of the planar waveguide are studied and the dispersion characteristics of the waveguide are studied based on the finite element algorithm.Then,the waveguide mode analysis and dispersion solution are designed.The waveguide structure is designed and the waveguide dispersion is calculated.Through the comparison of the smoothness of the dispersion curve,the dispersion value and the zero dispersion point position,the waveguide structure is optimized.The waveguide is obtained by studying the mode characteristics of the ordinary wave guide.The larger main mode cut-off wavelengths,wider bandwidth and low characteristic impedance make the effective mode area of the light wave in the waveguide to be well controlled,and the pulse energy can be effectively bound in the planar waveguideFinally,the generalized nonlinear Schrodinger equation of the pulse envelope is established and the influence of the nonlinear effect is studied.The numerical simulation of the pulse into the nonlinear material,under the interaction of the dispersion and nonlinear effects,the pulse light is broadened in the frequency domain.In theory,the femtosecond pulse is selected as the pump source,the incident pulse center wavelength is 4 μm,the pulse width is 180 fs,and the output spectrum intensity is at-40dB.The spectrum width is 2 to 7.5 μm.