US 12,393,064 B2
Semiconductor optical modulator
Josuke Ozaki, Musashino (JP); and Yoshihiro Ogiso, Musashino (JP)
Assigned to Nippon Telegraph and Telephone Corporation, Tokyo (JP)
Appl. No. 18/006,835
Filed by Nippon Telegraph and Telephone Corporation, Tokyo (JP)
PCT Filed Jul. 29, 2020, PCT No. PCT/JP2020/029132
§ 371(c)(1), (2) Date Jan. 25, 2023,
PCT Pub. No. WO2022/024276, PCT Pub. Date Feb. 3, 2022.
Prior Publication US 2023/0273467 A1, Aug. 31, 2023
Int. Cl. G02F 1/025 (2006.01); G02F 1/21 (2006.01); G02F 1/225 (2006.01)
CPC G02F 1/025 (2013.01) [G02F 1/212 (2021.01); G02F 1/2257 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A semiconductor optical modulator comprising:
a radio frequency (RF) line which is disposed parallel to an optical waveguide and is a differential configuration for transmitting an RF modulation signal,
a connecting pad which is formed in the same direction continuously with the RF line, and
a termination resistor which has two rectangular resistors for differentially terminating the RF modulation signal from the connecting pad, wherein
the RF line, the connecting pad, and the termination resistor are linearly disposed, and the RF line is terminated on-chip, and
an opposite side of the connecting pad of the termination resistor is short-circuited,
wherein
the connecting pad and the termination resistor are formed on at least one or more n-type or p-type semiconductors and at least one or more non-doped semiconductor layers,
the optical waveguide is formed in an independent high-mesa structure,
the semiconductor optical modulator has a higher-order mode light emitting structure for emitting higher-order mode light of a multimode interference coupler of a Mach-Zehnder interference system configured in a high-mesa structure, and
the resistor is disposed on the higher-order mode light emitting structure.