This project belongs to the field.  Broadband networks are strategic infrastructure that plays an important supporting role in promoting national transformation and development, promoting information consumption, and effectively stimulating investment. IEEE 802.3 predicted in 2011 that network traffic will increase tenfold by 2015 and 100 fold by 2020. How to effectively reduce the size, power consumption and cost of transmission equipment while increasing transmission capacity has become an urgent need for upgrading optical network equipment. With the support of the National 863 Project, the National Science Fund for Distinguished Young Scholars, the General Fund, the Youth Fund and Shanghai City, this project conducts long-term research on the generation, transmission and device technology of broadband photonic signals. The main inventions include: 

1) Based on new modulation technology to increase capacity, while reducing the number of modulators in the transmitter to reduce volume. A dual-drive Mach-Zehnder modulator (MZM) and electrical signal preprocessing are used to generate a (carrier-suppressed) return-to-zero-differential (quadrature) phase-shift keying (((CS)RZ-D(Q)PSK) signal, which reduces the number of modulators by 50%-67% compared with domestic and foreign solutions. A dual parallel Mach-Zehnder modulator (DPMZM) and a phase modulator are used to generate star 16-quadrature amplitude modulation (QAM), square 16-QAM and 16-amplitude phase-shift keying (APSK) signals, which reduces costs and is flexible in code generation.  

2) Improve the performance of optical communication systems through technologies such as optical signal-to-noise ratio (OSNR) monitoring, wavelength stability control and phase control of QAM. The invention can simultaneously monitor the in-band OSNR, signal spectrum and filtering effect, and the wavelength resolution is 0.002 nm, which is about 0.1 nm compared with the traditional spectral measurement method.  

3) To achieve small size through silicon-based devices, an all-optical single sideband up-conversion device with a radius of 20μm, an all-optical time-domain differential shaping device with an area of 5000μm2,~With a 1200μm2 40G photonic radio frequency phase shifter, the device size has been reduced from centimeter level of discrete devices to submillimeter level.  

A total of 60 invention patents have been applied for this project, of which 36 have been authorized and 24 are in the public stage. Published a total of 80 papers closely related to invention content, of which 20 representative international journal papers were cited 241 times by SCI.  The research results were transformed into OTN products of Fiberhome Communications Co., Ltd. and applied in units such as China Telecom, China Unicom and China Mobile. Evaluation of C114 China Communication Network: ... Board integration has been doubled, unit power consumption has been reduced by 50%, effectively reducing floor area and power consumption, and reducing operation and maintenance costs;... Meet the expansion needs of operators in the next five years. The Telecomasia website evaluated this achievement as the 2013 Optical Network Innovation. In the past three years, the project products have achieved an added unit output value of 476 million yuan, an added profit of 119 million yuan, and an added tax revenue of 23.8 million yuan.