%0 Journal Article
%A FANG Xin-xin
%A LIU Tao
%A SUN Chun-yang
%A WANG Ping-ping
%A ZHU Cong
%T Flattop Broadband Wavelength Converters Based on Cascaded Sum+Difference Frequency Generation
%D 2019
%R 10.13190/j.jbupt.2018-311
%J Journal of Beijing University of Posts and Telecommunications
%P 127-132
%V 42
%N 5
%X In order to improve the conversion characteristics of wavelength converters,the effect of the segmented quasi-phase matched grating structure in the periodically poled lithium niobate crystal on the characteristics of wavelength converters based on cascaded sum + difference frequency generation is studied. For both of single-pass and double-pass configurations, high conversion efficiency, large conversion bandwidth, and good flatness can be achieved simultaneously by increasing the number of segments and optimizing the poling period of each segment. Under the same conditions, the conversion efficiency and flatness of the double-pass configuration are better, but the conversion bandwidth is slightly worse than that of the single-pass configuration. Compared with the method of shifting the wavelength of one of the pump light, the use of segmented quasi-phase matched grating structure in wavelength converter can obtain almost the same flatness but better conversion efficiency and conversion bandwidth. Moreover, the effect of crystal length on the characteristics of a wavelength converter based on the segmented quasi-phase matched grating structure is also investigated.
%U https://journal.bupt.edu.cn/EN/10.13190/j.jbupt.2018-311