Study On The Propagation Losses And Fabrication Of The Channel Waveguides Of The Ag-Na Ion-exchange Glasses

Ion-exchange glass waveguides have advantages like low propagation losses, low productive cost and easy of integration, etc., in optical communications and optical sensing field it has excellent prospects to apply. The process to make ion-exchange waveguides is sample, but measuring the parameters of waveguides and evaluating the quality of the sample is too complex. Determining and realizing the parameters of planar waveguides (like the refractive profiles, the propagation losses, etc.) are the base to choose glass substrates and design optimize devices in the future. Using prism coupling method and inverse WKB method to get refractive profile of planar waveguides, but there are so many methods to measure propagation losses and these methods are too complex. We know that propagation losses are the important parameters to show the waveguide qualities, so it is important to find a sample and convenient method.In conventional methods to measure propagation losses, there are cut-off method, end fire method, sliding-prism method, three-prism method and Fabry–Perot method. Cutting sample into small pieces, cut-off method is the method that make damage to the sample; the result is not exact for low losses sample with end fire method; putting prism on one rolling guide in sliding-prism method, measuring the information of light intensity of every point to calculate the losses, this method need more experimental skills; needed more long samples with three-prism method; Fabry–Perot method is not suitable to measure propagation losses of planar waveguides. We use a new method to measure the propagation losses of planar waveguides- light scattering method. Using CCD camera in light scattering method commonly, in this paper the digital photographs of propagation lines of ion-exchange planar glass optical waveguides were taken by a common digital camera. According to the profiles of light intensity of propagation lines, the attenuation curves were fitted and the propagation losses of the waveguides were calculated. This way is more convenient and simple, making no damage to the waveguidesAny development of technique is preparation to make devices, researching the arts and crafts and characteristic of channel waveguide is very important with the ion-exchange method to make devices. So in this paper the main work is to research the measurement of the planar waveguides propagation losses and the process to make channel waveguide. Following is the content:First, using Ag-Na ion-exchange technique to make planar glass waveguides, then doing anneal to the sample. We can use the prism couple method and the inverse WKB method to get the refractive profile of planar waveguide before and after annealing, respectively. The digital photographs of propagation lines of ion-exchange planar glass optical waveguides were taken by digital camera—a very common setup, got the propagation losses by fitted with Matlab. Compared the propagation losses result before and after annealing, the result show that the propagation losses increase with the modes increase. This result is equal to the characteristic of waveguide, the mode order is high, and the depth is deep. So compared between high order modes and low order modes, in high order modes the propagation path is more long in propagation line and light wave act with the surface of waveguide-air many times, so the propagation losses is higher. From the results, annealing can reduce the propagation losses, the propagation losses can reduce half after annealing. Especially, the losses of the zero-mode can reduce one-third. The refractive profile is changed after annealing, the grads of refractive profile reduce. The refractive index is reduced clearly on the surface of sample. The losses are made by the action between light and the surface of glass. In other hands, the defects in the glasses can be eliminated by annealing, and the propagation can be reduced.At last, we make channel waveguides on glass substrates with Ag-Na ion-exchange method by micro electronics arts and crafts-photolithography technique, using prism coupling to get the difference of modes between channel waveguide and planar waveguide, getting the trend of refractive profile. Getting parameters of devices with end fire method, etc, then we show the whole process to make channel waveguide. Finally, using finite difference method to simulate with simple directional coupler, getting the parameters we need for preparation to design and make ion exchange waveguide devices in the future.