Patent ID: 6741378
Filing Date: 2004-05-25
Classification: G02F

Abstract:
An optical modulator comprising:an electrooptic effect element having a signal electrode and a ground electrode thereupon each provided with a pad, and varying optical phase by the electrooptic effect a relay substrate constituted of a dielectric wafer on which a coplanar waveguide connected to the signal electrode pad and the ground electrode pad on the electrooptic effect element is formed; and a connector having a center conductor and an external conductor respectively connected to the coplanar waveguide of the relay substrate, and supplying a modulation signal of microwave band to the signal electrode of the electrooptic effect element, wherein, when the modulation signal includes a component of 30 GHz, a pad space between the signal electrode pad and the ground electrode pad of the electrooptic effect element is defined as S &mgr;m, and a pad height is defined as H &mgr;m, the pad height is no greater than 300 &mgr;m, and the relation is set as âˆ’0.002H2+1.3Hâˆ’1602âˆ’1.6H+550.