US 12,009,864 B2
Optical transmitter, optical transmission system, and method of transmitting an optical signal
Mingqi Wu, Tokyo (JP)
Assigned to NEC CORPORATION, Tokyo (JP)
Appl. No. 17/795,934
Filed by NEC Corporation, Tokyo (JP)
PCT Filed Feb. 10, 2020, PCT No. PCT/JP2020/005125
§ 371(c)(1), (2) Date Jul. 28, 2022,
PCT Pub. No. WO2021/161383, PCT Pub. Date Aug. 19, 2021.
Prior Publication US 2023/0057029 A1, Feb. 23, 2023
Int. Cl. H04B 10/50 (2013.01); G02F 1/01 (2006.01)
CPC H04B 10/50575 (2013.01) [G02F 1/0123 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An optical transmitter comprising:
a light source configured to output a light;
a first optical modulator configured to modulate the light and output a first modulated optical signal;
a DC component detector configured to detect a DC component of the first modulated optical signal; and
a controller configured to apply a first specific bias voltage, identified using the DC component, to the first optical modulator,
wherein the controller is configured to identify the first specific bias voltage using a variance amount of the DC component of a modulated optical signal generated by each of a plurality of bias voltages,
wherein the controller is configured to change values of a bias voltage corresponding to a modulated optical signal having the variance amount of the DC component above a first threshold within a predetermined range,
wherein the controller is configured to replace the values of the bias voltage corresponding to the modulated optical signal having the variance amount of the DC component above a second threshold, and
wherein the second threshold is bigger than the first threshold.