We demonstrate an optical filter based on multistage second-order microring resonators（MRs） with box-like spectral responses. Compared with single-stage high-order optical filters with the same number of MRs,the dem...We demonstrate an optical filter based on multistage second-order microring resonators（MRs） with box-like spectral responses. Compared with single-stage high-order optical filters with the same number of MRs,the demonstrated structure has comparable performances in the aspects of passband flatness, rolling-off slope and insertion loss. Moreover, the architecture relaxes the fabrication tolerance, electrical wiring and tuning difficulty since there are only two MRs in each stage. We experimentally demonstrate this kind of optical filter with five stages, which shows a 3-dB bandwidth of ~17 GHz, a rolling-off slope of ~5 dB/GHz and an on-chip insertion loss of ~6 dB.展开更多
An algorithm is proposed for the fast reconstruction of off-axis digital holograms based on a combination of complex encoding（CE） and spatial multiplexing（SM）. In this algorithm, every two off-axis holograms recor...An algorithm is proposed for the fast reconstruction of off-axis digital holograms based on a combination of complex encoding（CE） and spatial multiplexing（SM）. In this algorithm, every two off-axis holograms recorded in sequence are first assembled into a CE hologram using the CE method, and then four of the CE holograms are again encoded into one complex spatial multiplexing（CSM） hologram based on the SM algorithm. It is demonstrated that the eight holograms encoded into such one CSM hologram can be quickly reconstructed by performing a two-dimensional（2D） Fourier transform（FT） on the CSM hologram. Using this method, the eight 2D FTs required for the reconstruction of the eight holograms in the conventional spatial filtering methods can be simplified to a process with only one 2D FT, which can largely improve the computation efficiency with the展开更多
基金Project supported by the National High Technology Research and Development Program of China(Nos.2015AA017001,2015AA010103)the Natural National Science Foundation of China(NSFC)(Nos.61235001,61575187,61535002,61204061,6157031748,61377067)
文摘We demonstrate an optical filter based on multistage second-order microring resonators（MRs） with box-like spectral responses. Compared with single-stage high-order optical filters with the same number of MRs,the demonstrated structure has comparable performances in the aspects of passband flatness, rolling-off slope and insertion loss. Moreover, the architecture relaxes the fabrication tolerance, electrical wiring and tuning difficulty since there are only two MRs in each stage. We experimentally demonstrate this kind of optical filter with five stages, which shows a 3-dB bandwidth of ~17 GHz, a rolling-off slope of ~5 dB/GHz and an on-chip insertion loss of ~6 dB.
基金supported by National Natural Science Foundation of China under Grant No.11474186
文摘An algorithm is proposed for the fast reconstruction of off-axis digital holograms based on a combination of complex encoding（CE） and spatial multiplexing（SM）. In this algorithm, every two off-axis holograms recorded in sequence are first assembled into a CE hologram using the CE method, and then four of the CE holograms are again encoded into one complex spatial multiplexing（CSM） hologram based on the SM algorithm. It is demonstrated that the eight holograms encoded into such one CSM hologram can be quickly reconstructed by performing a two-dimensional（2D） Fourier transform（FT） on the CSM hologram. Using this method, the eight 2D FTs required for the reconstruction of the eight holograms in the conventional spatial filtering methods can be simplified to a process with only one 2D FT, which can largely improve the computation efficiency with the
