Driver Integrated IQ Optical Modulator

1 . A driver integrated IQ optical modulator, comprising:

an IQ modulator comprising at least two or more Mach-Zehnder modulators; and

a differential driver IC connected to the IQ modulator,

wherein each of the at least two or more Mach-Zehnder modulators comprises a differential transmission line,

the differential transmission line comprises two signal lines for transmitting high-frequency modulated signals including differential signals,

the differential transmission line includes a PAD portion for connection with another element, a lead line portion, a phase modulation portion, and a termination portion, and the other element includes the differential driver IC,

the PAD portion includes a set of four first metal PADs having a GSSG configuration or a set of five first metal PADs having a GSGSG configuration, in which G is Ground and S is Signal, and

the lead line portion, the phase modulation portion, and the termination portion have an SS line configuration.

2 . The driver integrated IQ optical modulator according to claim 1 , wherein the differential driver IC includes a set of four second metal PADs with a GSSG configuration or a set of five second metal PADs with a GSGSG configuration, and

the set of four second metal PADs or the set of five second metal PADs are connected by wires to the corresponding set of four first metal PADs or the set of five first metal PADs.

3 . The driver integrated IQ optical modulator according to claim 2 , wherein a wire connecting the second metal PAD provided in the differential driver IC and the first metal PAD provided in the IQ modulator is configured through ball bonding,

each configuration between the first metal PAD and the second metal PAD associated with Signal in the GSSG configuration or the GSGSG configuration is connected to a set of four wires,

a pair of a first wire and a second wire of the set of four wires has substantially the same path in top view and different paths in side view,

a pair of a third wire and a fourth wire in the set of four wires has substantially the same path in top view and different paths in side view, and

a pair of the first wire and the third wire of the set of four wires has different paths in top view and substantially the same path in side view.

4 . The driver integrated IQ optical modulator according to claim 2 , wherein, in at least one of the set of the second metal PADs provided in the differential driver IC and the set of the first metal PADs provided in the IQ modulator,

a wire is connected between the first metal PADs or between the second metal PADs related to Ground in the GSSG configuration or the GSGSG configuration, and

the wire connecting between the first metal PAD or between the second metal PAD associated with the Ground is configured to surround a wire connecting between the first metal PAD and the second metal PAD associated with Signal of the GSSG configuration or the GSGSG configuration.

5 . The driver integrated IQ optical modulator according to claim 2 , wherein the first metal PAD associated with Ground closest to the periphery of the IQ modulator of the set of the first metal PADs having the GSSG configuration provided in the IQ modulator or the set of the first metal PADs having the GSGSG configuration is connected to an external ground potential.

6 . The driver integrated IQ optical modulator according to claim 5 , wherein each of the at least two or more Mach-Zehnder modulators includes the phase modulation portion has a capacitance loading structure, and the impedance of the capacitance loading structure is 3% or more higher than the impedance of a terminal resistor provided in the termination portion.

7 . The driver integrated IQ optical modulator according to claim 2 , wherein the set of the second metal PADs provided in the differential driver IC is installed at a higher position than the set of the first metal PADs provided in the IQ modulator.

8 . The driver integrated IQ optical modulator according to claim 1 , wherein the Mach-Zehnder modulator includes a semiconductor substrate, a waveguide structure formed on the semiconductor substrate, and a layer formed on the semiconductor substrate using a low dielectric material to embed the waveguide structure, and

the set of first metal PADs is formed on a layer formed using the low dielectric material.