The Investigation Of Photorefractive Effect And Photonic Crystal In Waveguides Of Oxide Optical Crystals

Integrated optics is firstly proposed by Miller in Bell laboratory, to research optical phenomena in optical materials and integrated optical components, to solve optical transmission and optical signal processing problems in communication. With the increasing growth of information, ordinary wire communication already could not satisfy our demands, and so optical waveguide structures and optical fibers are widely used. Integrated optics can integrate optical devices and optical waveguide structures on one substrate to achieve one or more optical functions. Compared with integrated circuits, integrated optical circuits have natural advantages, because photons do not interfere with each other. Compared with the traditional optical devices, integrated optics devices are smaller, lighter, and cheaper. Because all the components of integrated optics are integrated on a same substrate, so the coupling adjustment problem between the components is avoided, also the stability is stronger, which is the important advantage of integrated optics.Waveguide structure is an important part in integrated optics, and most optical components are base on waveguide structure. Waveguide is a structure with cross section of microns or submicron, with a high refractive index part surround by low refractive index parts. Because the size of waveguide structure is very small, the density of optical power is very high even the power of incident light is very low. The corresponding features of the bulks, such as nonlinear effect and photorefractive effect, maybe improved in waveguide structure.Lots of materials are used to fabricate waveguide structure, such as glass, crystal, polycrystalline materials, and polymer. Because they have good optical properties such as nonlinear optics, photorefractive properties, fluorescent properties, frequency doubling properties and photoelectric thermal performance, are widely used in optical devices. The fabrication of waveguide structures in optical materials, and the study of their optical properties are hot topics in integrated optics.Within all these materials, lithium niobate (LiNbO3) is one of the most widely used materials in integrated optics, because it has excellent optoelectronic and nonlinear properties. Lithium niobate waveguide is widely used in optical fiber communication, optical devices and integrated optoelectronics. Potassium titanyl phosphate (KTiOPO4, KTP) is another excellent nonlinear optical crystal, especially suitable for making frequency doubling device, and lots of methods can be used to fabricate KTP waveguide structure.Many methods have been developed to fabricate waveguide structure, such as Energy ion implantation, Direct ultrafast laser writing, Selective light induction, Ion exchange, Metal ion diffusion and Ion slicing. We use ion implantation to fabricate optical waveguide. During implantation, the losses of incident ions aroused nuclear energy deposition and electronic energy deposition and change the surface refractive index profile of the material, which form waveguide structures. The positive index changes in the waveguide region form an optical well and the negative index changes in the trajectory end of the incident ions form an optical barrier.Photonic crystal is a type of manufactured photonic materials, which can form photonic band gap. In recent years, photonic crystal theory of analysis method, fabrication method and novel photonic crystal optoelectronic devices emerge.In this dissertation, we report fabrication, characterization and application of planar and channel waveguide in Fe:SLN and KTP, and fabrication photonic crystal in channel KTP waveguide.We report on the two-wave mixing of light in photorefractive waveguides in H ion-implanted Fe-doped near-stoichiometric lithium niobate crystals. For pump light of 632.8 nm wavelength, a gain coefficient as high as 15 cm-1 is found. A response time of the order of a few seconds is achieved for micro-watt input powers.We report on the fabrication of planar and channel waveguides in KTP by implantation of multiple energy helium and oxygen. The refractive index profile is reconstructed, and both TE and TM modes are typical "well+barrier" shape, ’which has good confinement of light propagation.We report on the fabrication of large refractive index contrast planar waveguide by smart cut method and photonic crystal structure KTP channel waveguide by FIB.