Patent ID: 11888529
Assignee: HUAWEI TECHNOLOGIES CO., LTD.
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. A method for controlling a coherent transmitter, wherein the method comprises:
splitting, using a first beam splitter, a first optical signal to obtain a second optical signal and a third optical signal;
modulating, using a first modulator, the second optical signal to obtain a first modulated signal;
modulating, using a second modulator, the third optical signal to obtain a second modulated signal, wherein the first modulated signal and the second modulated signal have a same phase;
adjusting, using a phase shift adjuster, a first phase of a first sub-signal in the first modulated signal;
adjusting, using the phase shift adjuster, a second phase of a fourth sub-signal in the first sub-signal, wherein there is a first phase difference between the first sub-signal and the first modulated signal and a second phase difference between the fourth sub-signal and the first modulated signal, and wherein the second phase difference is twice as large as the first phase difference;
combining, using a first beam combiner, a second sub-signal in the first modulated signal and the fourth sub-signal to obtain a first combined signal;
combining, using a second beam combiner, a third sub-signal in the first sub-signal and the second modulated signal to obtain a second combined signal;
performing, using a first photodiode (PD), optical-to-electrical conversion on the first combined signal to obtain a first electrical signal; and
controlling, using a controller and based on the first electrical signal, a first voltage applied to the phase shift adjuster, to cause the first phase difference between the first sub-signal and the first modulated signal to fall within a preset range.