| 摘要 |
PURPOSE:To drop the voltage of an optical device and to make the resulting titled substrate useful to reduce the size of the device and to integrate the device and optical IC, by forming a PLZT layer on an insulating substrate and an insulating load layer on the PLZT layer. CONSTITUTION:A PLZT layer 22 is formed on an insulating substrate 21 made of MgO, spinel, sapphire or the like, and an insulating load layer 23 made of TiO2, Ta2O5, ZnO, Al2O3 or the like is formed on the leyer 22 to manufacture a substrate for an optical circuit. Since the PLZT film having a significant electrooptic effect is used unlike a conventional substrate for an optical circuit, the driving voltage of an optical device can be dropped. Even when the waveguide has <=20mum distance between lines, light waves can be propagated in the waveguide with no propagation loss, so the resulting substrate is useful to drop the voltage of the optical device. The substrate has little surface unevenness and causes no breaking of electrode wiring, etc., so it is useful to reduce the size of the optical device and to integrate the device and optical IC. |
