摘要 |
An electro-optic wave guide substrate for both intensity modulating and continuously deflecting an incident laser beam. A first set of electrodes for intensity modulating the beam include substantially parallel, periodically interdigital conductors affixed to a substrate surface and coupled to a controlled voltage source. A second set of electrodes for beam deflecting have non-parallel conductors affixed to the same substrate and are also coupled to a controlled voltage. By controlling the voltage applied to the second set of electrodes the beam can be continuously deflected through a controlled angle to facet track a rapidly rotating multi-faceted mirror of a raster output scanner. The substrate is fabricated using a new technique whereby the atmosphere in which the waveguiding surface is diffused is controlled. In particular, the diffusion is done in a heated oxygen environment having an elevated moisture content. The elevated oxygen concentation tends to oxidize impurities in the substrate and the moisture tends to form lattice sites for trapping mobile charge carriers. Both effects reduce the incidence of optical damage in the wave guide caused by the laser beam. |