Study On Design And Preparation Of Two-dimensional Chalcogenide Glass Photonic Crystal Waveguides

With the high optical nonlinearity, good infrared transmission of chalcogenide glass and uniqueslow-light characteristics of photonic crystal waveguides， two-dimensional chalcogenide glass photoniccrystal wavegduides become a promising platform for integrated all-optical nonlinear devices at infraredwavelengths. Compared to traditional waveguides made by quartz, Two-dimensional chalcogenide glassphotonic crystal wavegduides can be widely used in areas of all-optical buffer, photonic crystal lasers, highsensitive sensor at infrared wavelengths and so on.In this paper, we studied the theoretical design and experimental preparation of two-dimensionalchalcogenide glass photonic crystal wavegduides. Theoretically, we investigated the relationship betweenslow-light characteristics and structural parameters of the designed photonic crystal wavegduides. Byoptimizing the structure parameters, wavegduides with low dispersion, large bandwidth slow light wereobtained. In the experimental preparation, we used two different methods for the preparation oftwo-dimensional chalcogenide glass photonic crystal wavegduides and investigated their characteristics.The thesis was organized as follows:In chapter one, we briefly described the research progress especially in areas of slow-light andfabrication, of photonic crystals and two-dimensional photonic crystal wavegduides. Then chalcogenideglass and two-dimensional photonic crystal wavegduides made by chalcogenide glass were introduced. Andthe deficiencies and difficulties in investigation of chalcogenide glass two-dimensional photonic crystalwavegduides were analyzed. Finally, the general idea and content of this paper was mentioned.In chapter two, we introduced some basic theoretical analysis methods for photonic crystal and thebasic operation of the optical software RSoft. The main calculation realizations include plane waveexpansion method and finite-difference time-domain method, which were utilized by RSoft.In chapter three, two-dimensional chalcogenide glass photonic crystals with large bandgap weredesigned. The relationship between bandgap and the radius of air holes, the thickness of slab wereinvestigated. And photonic crystals with large bandgap were obtained, which allowed the modes ofwaveguides.In chapter four, we studied the slow-light characteristic of two-dimensional chalcogenide glassphotonic crystal wavegduides at communication wavelength and infrared wavelength. We designedsymmetric and asymmetric structure waveguides, and investigated their slow light characteristics.Concretely, the relationship between slow-light characteristic and the radius of air holes, which were thefirst two rows and the second two rows next to the waveguide, was investigated. The results showed thatthe asymmetric structure waveguides had more advantages than the symmetric ones. We also investigatedthe slow light propagation loss of two-dimensional chalcogenide glass photonic crystal wavegduides atcommunication wavelength and infrared wavelength, respectively, and found that waveguides had lowerslow light propagation loss at infrared wavelength than the loss at communication wavelength. In the end,depending on those investigations, we designed several waveguide structures with low dispersion, large bandwidth and high group velocity.In chapter five, two different methods for the preparation of two-dimensional chalcogenide glassphotonic crystal wavegduides were introduced. We prepared Ge20Sb15Se65chalcogenide glass films bymagnetron sputtering, and then focused ion beam (FIB) and electron beam lithography (EBL) were used tofabricated two-dimensional chalcogenide glass photonic crystal wavegduides respectively.In chapter six, we concluded all results of the present work and pointed out some shortages whichshould be improved in the future.