| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical modulator operated with a small RF drive voltage as well as a small DC bias voltage. <P>SOLUTION: An optical modulator comprises: a substrate; an optical waveguide formed on the substrate; a progressive wave electrode including a center electrode and a ground electrode for a high frequency electric signal where a high frequency electric signal is transmitted; and a bias electrode for applying a bias voltage. The optical waveguide includes a high frequency electric signal interaction part and a bias interaction part, and a ridge portion is formed by recesses obtained by digging a part of the substrate along the optical waveguide in both the high frequency electric signal interaction part and the DC bias interaction part. The ridge portion has a different height in the high frequency electric signal interaction part from that in the DC bias interaction part, and the height of the ridge portion in the DC bias interaction part is smaller than the height of the ridge portion in the high frequency electric signal interaction part. <P>COPYRIGHT: (C)2012,JPO&INPIT |
