Investigation On Copper Ion Exchange Glass Planar Waveguides And Their Properties

As the most suitable technique for making optical waveguides on glass substrate, ion exchange technique is an important method for fabricating glass waveguides. In this thesis, two main methods have been used for preparing glass waveguides, thermal ion exchange technique and metal-film ion exchange technique. Due to the advantages of large data transmission rates, shorter and shorter distances, as they have well capability of data confidentiality and anti-jamming. So the optical waveguides made by ion exchange have extensive applications in many fields, such as the ion exchange glass waveguides have many advantages, such as optical interconnects, optical sensing and so on. Compared to K+ ions exchange and Ag+ ions exchange, Cu ions exchange technology, with its unique blue-green luminescence properties and the complex relationship of the coexistence of Cu+,Cu2+, has been regard as the glass waveguide technology of research value. The main method used in this thesis is Cu ion exchange technology, an important method for preparing glass waveguide.Research results indicate that copper ion exchange glass planar waveguides made by thermal ion exchange technique not only very sensitive on two parameters, time and temperature, but also produces blue-green luminescence properties, therefore the research for the technology will have very good application prospects.In this thesis, we mainly study the luminescence properties and refractive index profiles of copper ion exchange glass planar waveguides made by thermal ion exchange technique and metal-film ion exchange technique. Briefly introduce ion exchange technology and its development, and more detailed in the mechanism of the ion-exchange glass waveguide refractive index changes and common measurement and characterization techniques.The exchange process of thermal copper ions are complicated that the coexistence of the exchanged ions and their cluster of Cu+,Cu2+ ,different preparation time and temperature will be affect concentration profiles of Cu+,Cu2+, the dimension of ions cluster and the diversion of Cu+,Cu2+, and then affect the properties of the waveguide. For copper ion exchange glass waveguides, Cu+, Cu2+ will diffuse into different regions; and their contributions to the refractive index change are different. In present, many papers have reported the ion exchange glass optical waveguides and their properties, however, there are barely the research on the effect of time and temperature, the two important preparing parameter on waveguide and related properties. We report the study on mode of sample, and refractive index profiles and photoluminescence of different samples prepared under various exchange time and temperature to obtain related information about how the copper ion exchange process influence the properties of planar optical waveguides.Soda-lime glass planar optical waveguides were fabricated by copper ion-exchange technique in different times and temperature. The effective indices were measured by prism coupling method and the refractive index profiles of the planar waveguides were reconstructed by inverse WKB method. The research results indicate that ion exchange time and temperature have great impact on the properties of optical waveguides. The number of the modes increase at first and then decrease with the ion-exchange time increasing. The maximum mode numbers and waveguide depths were obtained with a proper ion-exchange time(like 10 min). To the samples with efficient exchange time, we can not find the mode from prism coupling method. more Cu+ would be oxidized Cu2+,with the increase of ion exchange times which cause the decrease of surface refractive index and form the buried waveguide. When exchange time is about 10 minutes as the same, we test the room temperature luminescence properties of samples prepared under different temperature, and obtain the blue-green emission spectrum centered at 520 nm. The emission bands are typical for the emission of Cu+ ions that undergo the transition 3d94s1â†'3d10, luminous intensity increase with the increase of ion exchange temperature and rest the concentration of Cu+ ions and Cu2+ ions.Soda-lime glass planar optical waveguides were fabricated by metal-film ion exchange technique. Measured the effective indices of waveguide by prism coupling method, and compared the obtained results with those from samples made by thermal ion exchange technique. Research results indicate that in the metal-film ion exchange technique process, the exchange time, temperature and voltage all could influent the properties of glass planar optical waveguides. Compared to thermal ion exchange technique, this method has some advantages like longer time, smaller error, lower temperature, easier to control; however, because of the requirement of film and voltage, the techniques are relatively complicated. Research results show that the sample has absorb band only around 280 nm, which demonstrates the existence of Cu+, but the PL spectrum indicates that the samples made by metal-film ion exchange technique do not have the blue-green luminescence properties.