Optical modulator

An optical modulator comprising an optical modulation substrate, an electrical length adjusting substrate, a package containing said optical modulation substrate and said electrical length adjusting substrate, and a plurality of input ports for inputting high frequency electrical signals;

• wherein said optical modulation substrate comprises a substrate body comprising an electro-optic material, a plurality of signal electrodes provided on said substrate body, optical waveguides propagating lights interacting with said signal electrodes, respectively, and electrode input ports inputting said high frequency electrical signals into said signal electrodes, respectively;
• wherein each of said signal electrodes comprises an interacting part interacting with said optical waveguide, an input end part provided between said electrode input port and said interacting part, and a terminal part provided in the downstream of said interacting part;
• wherein said electrical length adjusting substrate comprises conductive lines connected to said input end parts and said input ports for inputting said high frequency electrical signals, respectively;
• and
• wherein said conductive lines have electrical lengths different from each other.