公开(公告)号：US11852948B2

公开(公告)日：2023-12-26

申请号：US17742812

申请日：2022-05-12

Applicant: Fujitsu Optical Components Limited

Inventor： Tetsuji Yamabana

IPC: G02F1/21 ,  G02F1/225 ,  G02B6/293 ,  G02F1/025

CPC classification number: G02F1/212 ,  G02B6/2935 ,  G02F1/025 ,  G02F1/225

Abstract: In an optical transmitter having an electro-optic modulator with first child MZI and a second child MZI nested to form a parent MZI, and a processor that controls the bias voltages of electro-optic modulator. In the first section of a control loop, the processor simultaneously superimposes different dither signals onto the first bias voltage of the first child MZI and the second bias voltage of the second child MZI, and extracts the first phase error information for the first child MZI and the first-round third phase error for the parent MZI from a first monitoring result. In the second section of the control loop, the processor simultaneously superimposes different dither signals onto the first and second bias voltages, and extracts the second phase error information for the second child MZI and the second-round third phase error for the parent MZI from a second monitoring result.

公开(公告)号：US11309971B2

公开(公告)日：2022-04-19

申请号：US17135593

申请日：2020-12-28

Applicant: Fujitsu Optical Components Limited

Inventor： Tetsuji Yamabana ,  Tsuyoshi Morishita

IPC: H04B10/50 ,  H04B10/556 ,  H04B10/564

Abstract: Controller and control method are provided. In particular, a controller is disclosed as being configured to hold intensities of a monitor signal, which changes according to an output from a region in a device, before and after altering a state of a portion in the region and control the state of the portion based on a difference between the held intensities.