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The production of low loss ion exchanged integrated optical components in glass usually requires buried waveguides, fabricated in a two step process. In addition, a strong sidediffusion of the ions is observed. Buried channel waveguides with negligible sidediffusion can be fabricated in a one step process by a suitable solid phase diffusion technique. We examined the field assisted solid phase ion exchange in glass to produce single- and multimode waveguides. Vapour deposited silverfilms could be structurized down to a linewidth of 2 μm, using common photoresist techniques. In order to achieve a homogeneous drift field during the diffusion process, the substrates were covered with a sodium nitrate melt. For applied drift fields of typically 150 V/mm (diffusion temperature: 588 K; diffusion time: 6 ... 15 min) the channel waveguides exhibited a negligible broadening even in the case of deep burial. Due to this fact an independent control of both lateral and vertical waveguide dimensions is possible, if the solution rate of silver for each type of glass is known. This allows the fabrication of waveguides by control of the silverstripe thickness and width with only small deviations. By this one-step-technique channel waveguides down to 4 μm nearfield diameter and an ellipticity of only 1.1 were buried 15 μm below the surface.
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