Study On The Characteristics Of Mid-infrared Crystal Optical Waveguides Prepared By Ion Irradiation Technolog

Optical waveguides consist of high-refractive-index regions surrounded by low-refractive-index regions,using the principle of total reflection to restrict the beam propagating forward within high-refractive-index regions.The performance of the optical waveguide directly affects the performance of the micro components,and then determines the working quality of the integrated optical components.At present,the study of optical waveguide in visible wavelength has been very extensive,but the study of optical waveguide in mid-infrared band is relatively scarce.In this article,we select the appropriate mid-infrared crystal materials,use the ion irradiation to prepare planar optical waveguides on the surface of mid-infrared crystal materials,and then use two precision machining methods of precision diamond blade dicing or femtosecond laser ablation technology to prepare ridge optical waveguides,and study the guide wave properties of prepared optical waveguides.The thermal annealing technology was innovatively proposed to optimize the transmission performance of optical waveguide and Raman spectroscopy was used to study the effect of ion irradiation on crystal lattice structure.According to the differences of manufacturing materials and processing methods,the content of the paper is summarized as follows:The CaF₂ crystal ridge waveguide was prepared by 25 MeV O⁵⁺ion irradiation and precision diamond blade.Guided wave performance was measured by end coupling system,and thermal annealing technology was used to optimize transmission performance.A CaF₂Crystal ridge waveguide with propagation loss of 0.5 d B/cm in 4μm TM mode is developed.Raman spectra show that the irradiation of 25 MeV O⁵⁺ion do not cause lattice damage of CaF₂ crystal.The experiment provides an experimental basis for the application of CaF₂crystal ridge waveguide in the field of mid-infrared integrated optics.The ridge waveguide was fabricated in ZnSe crystal by 15 MeV C⁵⁺ion irradiation combined with diamond blade dicing.The ZnSe crystal ridge waveguides with propagation loss of 0.8 d B/cm（λ=1.064μm）,0.6 d B/cm（λ=2.2μm）and 0.4 d B/cm（λ=4μm）have been developed by using the end coupling system combined with thermal annealing technology.Raman spectra show that 15 MeV C⁵⁺ion irradiation does not damage the crystal lattice of ZnSe crystal.It is proved that ZnSe crystal ridge waveguide with low loss has wide application prospect in the field of mid-infrared integrated optics.ZnS crystal ridge waveguide was fabricated by 25 MeV O⁵⁺ion irradiation and precision diamond blade dicing.A ZnS ridge waveguide with propagation loss reduced to 0.4 d B/cm in TE mode at 4μm wavelength was developed by using the end coupling system combined with thermal annealing treatment.At the same time,ZnS crystal ridge waveguide was fabricated by 1.2 Ge V Kr⁸⁺ion irradiation combined with femtosecond laser ablation.A ZnS ridge waveguide with propagation loss of 0.6 d B/cm in TE mode at 4μm wavelength was developed.Experimental results show that the low loss ZnS ridge waveguide can be widely used in the field of mid-infrared integrated optics.The BaF₂ crystal ridge waveguide was prepared by 15 MeV C⁵⁺ion irradiation and femtosecond laser ablation.The end-face coupling system measures the waveguide performance.A BaF₂crystal ridge waveguide with propagation loss of 0.5 d B/cm in TE mode at 4μm wavelength was developed by a series of thermal annealing treatments.Confocal Raman spectra show that the crystal lattice structure of BaF₂ crystal does not change after C⁵⁺ion irradiation.The experimental results show that the fabrication of BaF₂crystal ridge waveguide by the above method has an important application prospect in the field of mid-infrared integrated optics.