title: Fully integrated multi-optoelectronic synthesizer for THz pumping source in wireless communications with rich backup redundancy and wide tuning range.
abstract: We report a monolithic photonic integrated circuit (PIC) for THz communication applications. The PIC generates up to 4 optical frequency lines which can be mixed in a separate device to generate THz radiation, and each of the optical lines can be modulated individually to encode data. Physically, the PIC comprises an array of wavelength tunable distributed feedback lasers each with its own electro-absorption modulator. The lasers are designed with a long cavity to operate with a narrow linewidth, typically <4 MHz. The light from the lasers is coupled via an multimode interference (MMI) coupler into a semiconductor optical amplifier (SOA). By appropriate selection and biasing of pairs of lasers, the optical beat signal can be tuned continuously over the range from 0.254 THz to 2.723 THz. The EAM of each channel enables signal leveling balanced between the lasers and realizing data encoding, currently at data rates up to 6.5 Gb/s. The PIC is fabricated using regrowth-free techniques, making it economic for volume applications, such for use in data centers. The PIC also has a degree of redundancy, making it suitable for applications, such as inter-satellite communications, where high reliability is mandatory.
authors.affiliation: Institute of Semiconductors, Chinese Academy of Sciences, No. A35, East Qinghua Road, Haidian District, Beijing 100083, P.R. China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Xu
authors.affiliation: School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK.
authors.forename: Lianping
authors.initials: L
authors.lastname: Hou
authors.affiliation: Institute of Semiconductors, Chinese Academy of Sciences, No. A35, East Qinghua Road, Haidian District, Beijing 100083, P.R. China.
authors.forename: Qiufang
authors.initials: Q
authors.lastname: Deng
authors.affiliation: Institute of Semiconductors, Chinese Academy of Sciences, No. A35, East Qinghua Road, Haidian District, Beijing 100083, P.R. China.
authors.forename: Liangshun
authors.initials: L
authors.lastname: Han
authors.affiliation: Institute of Semiconductors, Chinese Academy of Sciences, No. A35, East Qinghua Road, Haidian District, Beijing 100083, P.R. China.
authors.forename: Song
authors.initials: S
authors.lastname: Liang
authors.affiliation: School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK.
authors.forename: John H
authors.initials: JH
authors.lastname: Marsh
authors.affiliation: Institute of Semiconductors, Chinese Academy of Sciences, No. A35, East Qinghua Road, Haidian District, Beijing 100083, P.R. China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zhu