US 12,444,902 B2
Optical transmitter
Shigeru Kanazawa, Musashino (JP); Takahiko Shindo, Musashino (JP); and Naoki Fujiwara, Musashino (JP)
Assigned to NTT, INC., Tokyo (JP)
Appl. No. 17/428,059
Filed by Nippon Telegraph and Telephone Corporation, Tokyo (JP)
PCT Filed Jan. 24, 2020, PCT No. PCT/JP2020/002453
§ 371(c)(1), (2) Date Aug. 3, 2021,
PCT Pub. No. WO2020/162217, PCT Pub. Date Aug. 13, 2020.
Claims priority of application No. 2019-019720 (JP), filed on Feb. 6, 2019.
Prior Publication US 2022/0149591 A1, May 12, 2022
Int. Cl. H01S 5/02325 (2021.01); H01S 5/02345 (2021.01); H01S 5/0239 (2021.01); H01S 5/026 (2006.01); H01S 5/062 (2006.01); H01S 5/10 (2021.01); H04B 10/50 (2013.01); H01S 5/12 (2021.01)
CPC H01S 5/02325 (2021.01) [H01S 5/02345 (2021.01); H01S 5/0239 (2021.01); H01S 5/06226 (2013.01); H01S 5/1085 (2013.01); H01S 5/0265 (2013.01); H01S 5/101 (2013.01); H01S 5/12 (2013.01); H04B 10/503 (2013.01)] 4 Claims
OG exemplary drawing
 
1. An optical transmitter, comprising:
a subcarrier;
an RF wiring board with wires and mounted on the subcarrier;
a modulated laser chip mounted on the subcarrier;
a terminating resistor mounted on the subcarrier;
a ground pad on an upper surface of the subcarrier; and
the wires electrically connecting at least a part of an electric path, the electric path extending from the RF wiring board to the ground pad and passing through the terminating resistor;
wherein:
an output optical waveguide of the modulated laser chip emits light at an angle of not 90 degrees to an emitting end face of the modulated laser chip;
the RF wiring board and the ground pad are arranged to sandwich the modulated laser chip in a width direction of the subcarrier,
the terminating resistor is a termination of an RF wiring and integrated on the RF wiring board and a width of the terminating resistor is approximately the same as a width of the RF wiring on the RF wiring board; and
a length of the wires in the electric path extending to the ground pad ranges from 0.5 to 1.5 mm or an inductance of the wires ranges from 0.4 to 1.2 nH.