Abstract: A method for producing waveguides in a glass substrate by ion exchange comprises the method steps of: (a) applying a metal mask (44) on the glass substrate (42), this metal mask (44) leaving open the areas of the waveguides (72,74) to be provided, (b) bringing the glass substrate (42) into contact with molten metallic salt which comprises the ions to be exchanged for the ions of the glass substrate (42), (c) interconnecting by means of electrical conductors surface areas (90,92,94,96) of the metal mask (44) that are separated from each other. The surface areas (90,92,94,96) of the metal mask (44) are electrically conductively interconnected through bond wires (98). Furthermore, the surface areas (90,92,94,96) are electrically conductively connected to a metallic vessel (12) which contains the molten metal.

Abstract: Zones having an increased refractive index shall be created as optical wave guides, or the like, in plane-parallel plates by ion exchange from a salt melting. For this purpose the plate is clamped between two holding hodies made of metal. The holding bodies form cavities (26,28) on both sides of the plate. These cavities are open towards the plate. The cavities are surrounded by closed sealing surfaces engaging the plate. Reservoirs for the salt melting communicate through filling conduits with the lower ends of the cavities. Vent conduits extend from the cavities.