Optical modulator

1 . An optical modulator in which an electro-optical conversion element and a driver circuit for driving the electro-optical conversion element are housed in the same case, comprising:

a multiplexer that converts an input modulation signal, which is input from an outside of the case, into an output modulation signal having a higher frequency than the input modulation signal, and supplies the output modulation signal to the driver circuit,

wherein the multiplexer and the driver circuit are disposed on a flip-chip substrate, the flip-chip substrate is housed in the case,

the input modulation signal is transmitted using a flexible printed circuit provided on the outside of the case,

a termination resistor for terminating the modulation signal applied to the electro-optical conversion element is provided on the flip-chip substrate, and

the multiplexer, the driver circuit, the electro-optical conversion element and the termination resistor are linearly arranged along the flip-chip substrate.

2 . The optical modulator according to claim 1 , wherein the multiplexer is parallel/serial conversion means.

3 . The optical modulator according to claim 1 , wherein the electro-optical conversion element and the flip-chip substrate are electrically connected by a flip-chip bonding.

4 . The optical modulator according to claim 1 , wherein the termination resistor is provided on one side of the flip-chip substrate and the electro-optical conversion element on the other side of the flip-chip substrate.