| Optical waveguide is the basis of the devices in integrated optics and optical telecommunication field, as signal propagation channels and equipments connected some devices with others. Optical waveguide structures allow confinement of the light in small volumes with dimensions of micrometer, which can improve the optical density and enhance many optical performances in the wave-guiding structures. Such a configuration is a promising feature for the practical application of waveguide devices as well as integrated optical circuits. So, the fabrication waveguide structure with high performance and the investigation of properties of waveguide are both important topic in integrated optics.At present, the infrared technology has been widely used in national defense, national economy and scientific research, and pays close attention to in the field of business. Infrared light in such aspects as communication, detection, medical and military have a wide range of applications, such as infrared imaging, infrared detection, infrared tracking, infrared guidance, infrared warning, and infrared countermeasures, which is an important strategic and tactical means in the modern and future war. Infrared optoelectronic devices show great potential application in the atmosphere of the testing and environmental monitoring, free space optical communication, infrared testing, clean energy, coal mine safety, molecular spectroscopy measurement, laser medical and biological technology. As the basis of integrated optoelectronic devices components, the performance of the optical waveguide structure plays a decisive role in the infrared optoelectronic devices.In view of the important application value of optical waveguide structure, several methods have been employed to manufacture optical waveguides, including ion implantation, swift heavy ion irradiation, ion exchange, diffusion, thin film deposition, focused ion beam writing and femtosecond laser inscription. As two kinds of energentic ion beam irradiation, the waveguide structure formed by ion implantation and swift heavy ion irradiation methods through the incident ion colliding with the target ions and changing the refractive index of the layer. The energentic ion beam irradiation has developed into a relatively mature method for waveguide fabrication due to the controllable energy and doses of the implanted ions and the depth of the waveguide layer etc.. Combined with the micromaching technology, such as photolithography technique, energentic ion beam irradiation technology can fabricate optoelectronic devices with different performances. So far, energentic ion beam irradiation technology has been successfully fabricated waveguide in several optical materials including crystals, insulators, glasses and polymer and so on.In this dissertation, we report the fabrication and optical properties of planar or channel waveguide structures formed by energentic ion beam irradiation technology in visible and infrared band. In this paper, we focus on the optical materials with transmitting infrared band, including LiNbO3, BBO, ZnSe, CdS, Nd:BSO, ZnS, glass and fused silica.The effective refractive index of modes, the refractive index distribution, mode field distribution and loss are the main characteristics of waveguide structures. There are many ways for representing the waveguide characteristics and the theoretical and experimental methods in our work are as follows:The Stopping and Range of Ions in Matter (SRIM) is used to simulate the process ion implantation; Reflectivity calculation method (RCM) or Intensity Calculation Method (ICM) is used to reconstruct the refractive index distribution; the plots of the light propagation is simulated by finite difference beam propagation method (FD-BPM); the effective refractive indices of the planar waveguide at633nm and1539nm are measured by the prism-coupling methods; the end-face coupling arrangement is used to measure the near-field intensity distribution of the guided light and the propagation loss the waveguide; annealing treatment can improve the optical properties. In addition, we measured the Raman spectrum and absorption spectrum to represent the damage properties of ion irradiation. Based on the above methods, we do the results are as follows:Compound semiconductor materials of Ⅱ-Ⅵ family is consisted by the family elements of ⅡA and ⅥA in the periodic table, which posses large ionic bond component, large range of forbidden band width and direct transition band structure and presents widely application in the devices of solid light, laser, infrared and piezoelectric effect etc. We have fabricated planar waveguide structure with an energy of6.0MeV on the polycrystal ZnS, CdS and ZnSe crystals and channel waveguide structure on the CdS and ZnSe crystals. The photoresist mask consisted of narrow strips with a period of50μm and a width of7μm. The microscope images of the planar or channel waveguide cross section are collected by a metallographic microscope. We measure the effective refractive indices of the guided modes at the wavelength of633nm and1539nm by prim-coupling measurements. The near-field intensity distribution of the guided light in visible and infrared band is measured by end-face coupling methods. According to the Sellmeier equation for Cleartran ZnS, the refractive index of the substrate at1300nm is estimated. The results show that the waveguide implanted by C ions with energy of6.0MeV can confine light by the barrier layer. The optical absorption spectra before and after implantation are measured by using a Jasco U570spectrophotometer. Our data shows that the ion implantation technique could be of interest for optical waveguide in optical materials in the visible and near-infrared bands.LiNbO3has been one of the most attractive materials due to its outstanding piezoelectric, ferroelectric, electro-optical, photoelastic, pyroelectric, photorefractive and nonlinear properties. The Li/Nb concentration ratio of the LiNbO3in our work is about48.3/51.7-48.6/51.4. Swift heavy ion with high energy and low fluences is used to irradiated on the LiNbO3crystal. A70-μm-thick Al foil is placed before the sample to slow down the incident Kr ions and reduce the ion energy to approximately1.7GeV. The incident Kr ion beam vertically irradiates the Al foil and the surface of the sample. The ion beam fluence is1×1011ions/cm2. The near-field intensity image of the light coupled out of the waveguide at633nm is recorded on the screen. The thickness of the irradiated layer is approximately150μm. There are two dark lines: one line in the irradiated layer and the other line at the end of the ion track in the LN crystal. The near-field intensity profiles at the wavelengths of633nm and4μm are obtained using end-face coupling setups. The Raman spectra at different depths in the Kr-ion-irradiated LN crystal and a virgin LN crystal are measured. The refractive index ne at the wavelength of4Μm in LN crystal is calculated according to the Sellmeier equation. The refractive index profile at a4μm wavelength is then estimated based on the refractive index (ne) profiles at633nm.Chalcogenide glasses are stable because of the relatively large atomic mass of their constituent atoms, including the chalcogen elements S, Se, Te, Ge, As, and Sb. Because of the relatively large atomic mass of their constituent atoms, chalcogenide glasses have low phonon energies. And the low phonon energies of250～450cm-1result in low non-radiative decay rates of rare-earth energy levels. Chalcogenide glasses are attractive because they have high refractive indices and enhanced IR transmission with low phonon energy. Chalcogenide glass has numerous potential applications in civil, medical, and military fields, among others. Planar waveguide structures have been fabricated in chalcogenide glass using swift heavy Kr ions with energies of17MeV or150MeV. These results demonstrate that swift Kr ion irradiation is a promising method for fabricating waveguide structures in chalcogenide glass.Fused quartz is pure SiO2and exhibits low coefficient of thermal expansion, low electrical conductivity, and excellent chemical stability. Fused quartz is a key material in fabrication of integrated devices, which transmits extends from ultraviolet to infrared. We report the fabrication of planar and channel waveguides in fused quartz using multi-energy C ion at energies of (5.0+5.5+6.0) MeV and fluences of (1+1+1.5)×1015ions/cm2. The guiding modes at the wavelength of633nm (He-Ne laser) and1539nm (diode laser) were detected using the prism-coupling method, and the modes were stable after annealing in air. The refractive index profiles of planar and channel waveguides at the wavelength of633nm and1539nm were typical "well+barrier" distributions, which were reconstructed using the reflectivity calculation method (RCM) software and intensity calculation method (ICM), respectively. For comparison to the experimental results, the finite difference beam propagation method (FD-BPM) was used to simulate the guiding modes of the waveguides. We measured the near-filed intensity distributions for the visible (633nm) and near-infrared (1300 nm,1539nm and1620nm) wavelength regions, suggesting that the modes can be effective transmission in the wavelength range for optical fiber communications.BBO is an abbreviation for beta barium borate (β-BaB2O4), which has been considered an attractive nonlinear crystal since it was discovered in1984. BBO exhibits a large second harmonic generation (SHG) coefficient (d22≈2.2pm/V), a wide range of transparency from190nm to3500nm, a high damage threshold, a wide phase matching angle and high nonlinear optical coefficients, as well as a high birefringence; all these qualities make BBO very attractive for nonlinear optical applications, especially UV applications. We report on z-cut P-BBO planar waveguide produced by multi-energy proton implantation in total of3×1016ion/cm2at room temperature. Multi-energy ion implantation can increase the damage range, broadening the optical barrier and reducing the leakage of light from the substrate through the barrier wall. Annealing at600℃for5hours prior to the implantation process is used to decrease the influence of the stress induced during the ion implantation process. Multi-energy proton implantation could be an effective method for waveguide formation in β-BBO crystal.Bismuth oxide crystals of the type Bi12M02o (M=Ge, Si, Ti), which have body-centered cubic structures and belong to the space group123, exhibit a number of remarkable properties, such as photorefractivity, photoconductivity, optical activity, and the electro-optic, piezoelectric, elasto-optic and electrogration effects and so on. Planar optical waveguides in Nd:BSO crystals were fabricated by the implantation of500keV He ions and6.0MeV C ions at two different substrate temperatures. The guiding modes were measured by the prism-coupling method with a He-Ne beam at633nm. |
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