The amplitude modulation/direct detection (IM/DD) method is adopted to achieve communication in the practical optical fiber communication system at present. By comparison with the traditional direct detection system, coherent optical transmission system has a lot of advantages, such as high sensitivity, long relay distance, good selectivity, large communication capacity and a variety of modulations. Based on coherent detection principle, ASK heterodyne asynchronous demodulation system is researched and designed. The signal light and the local oscillator light are mixed through the mixer. Then through the photoelectric conversion the intermediate frequency (IF) current signal is obtained when the difference frequency signal is input to detector. And then the signal in form of baseband signal is output after photocurrent signals passing through the electrical signal processing system. In paper, the circuit of receiver is implemented. And the correctness of circuit design is demonstrated by experiment. It lays a solid groundwork for further study of Heterodyne Asynchronous Demodulation System of coherent optical communications.

Date Published: 11 August 2011
PDF: 6 pages
Proc. SPIE 8195, International Symposium on Photoelectronic Detection and Imaging 2011: Terahertz Wave Technologies and Applications, 81951D (11 August 2011); doi: 10.1117/12.900827

Published in SPIE Proceedings Vol. 8195:
International Symposium on Photoelectronic Detection and Imaging 2011: Terahertz Wave Technologies and Applications
X.-C. Zhang; Jianquan Yao; Cunlin Zhang; Zhenzhan Wang, Editor(s)