Substrate cleaning for integrated optical waveguides.
Losses in integrated optical waveguides depend upon the homogeneity of the guiding layer. Successful production of acceptable guides by sputtering or solution deposition depends critically on the methods used to clean the substrate. Cleaning methods that produce films adequate for ordinary coatings have proved inadequate for integrated optical films. The extreme cleanliness required to produce low-loss waveguides can be achieved by a process described in this paper, which utilizes a precleaning step in an ultrasonically agitated detergent bath followed by careful rinsing in an ultrasonically agitated bath of heated, deionized, and filtered water. In addition to the cleaning method, we discuss the design of a cleaning station that combines the necessary apparatus in a portable unit.
Brandt
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GB
Supertzi
E P
EP
Henningsen
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T