Study On Nonlinear Effect Of Optical Wall In Echo Wall Mode

The whispering gallery mode optical cavity has extremely narrow mode linewidth,extremely high photon density,and strong mode light energy.It is widely used in nonlinear optics,optoelectronic devices,lasers and sensors.In this paper,the frequency doubling characteristics of the whispering gallery mode microring are studied by using the waveguide microring structure.The AlGaAs waveguide micro-ring three-layer structure is GaAs/Al_xGa_1-x-x As/Alo/Al_xGa_1-xAs in order,and has a thickness of 0.36?m and an outer ring radius of 6?m.The phase matching is realized by the combination of the form birefringence and the angle quasi-phase matching.When the center wavelength is 1.68?m and the TE mode light with a power of 30 mW is incident,the single-wavelength double-frequency conversion efficiency reaches 15%,and the 3 dB bandwidth is 1.68 nm.Secondly,by changing the Al composition x and AlGaAs layer thickness d in the AlGaAs microring,the 3dB bandwidth is further expanded and the conversion efficiency is improved.The study shows that when the Al composition x of the AlGaAs microring changes from 0.1 to 0.7,the center wavelength is 1.68?m,when the TE mode light with a power of 30mW is incident,the multiplier light of the TM mode will be generated.The 3dB bandwidth and the frequency conversion efficiency increase with the increase of x,and the widest bandwidth can reach 33nm,the highest conversion.The efficiency can reach 15.58%;among them,multiple wavelength multiplication occurs at x?0.4,and the frequency doubling effect is realized at multiple wavelengths around1.38?m,1.48?m,1.68?m,1.83?m;when the thickness of AlGaAs layer of AlGaAs microring is d When the change occurs,the frequency doubling effect also changes:the 3dB bandwidth and the frequency conversion efficiency decrease with increasing d,the narrowest bandwidth is 0.5nm,and the single wavelength is in the range of 0.7?m?d?1?m.Multiplier,d?0.7?m is multi-wavelength multiplier.At the same time,the whispering mode SiO₂ microspheres were prepared by melting CO₂ laser.The radius of the microspheres was 82?m.The simulation of the coupling between the microsphere cavity and the tapered fiber was carried out,and the factors affecting the coupling were analyzed.