A compact time delay unit is fundamental to integrated photonic circuits with applications in,for example,optical beam-forming networks,photonic equalization,and finite and infinite impulse response optical filtering....A compact time delay unit is fundamental to integrated photonic circuits with applications in,for example,optical beam-forming networks,photonic equalization,and finite and infinite impulse response optical filtering.In this paper,we report a novel gain-enabled delay readout system using a tunable optical carrier,low-frequency RF signal and CMOS-compatible photodetectors,suitable for silicon photonic integration.The characterization method relies on direct phase measurement of an input RF signal and thereafter extraction of the delay profile.Both integrated silicon and germanium photodetectors coupled with low-bandwidth electronics are used to characterize a microring resonator-based,true-time delay unit under distinct ring–bus coupling formats.The detectors,used in both linear and avalanche mode,are shown to be successful as optical-to-electrical converters and RF amplifiers without introducing significant phase distortion.For a Si–Ge separate-absorption-charge-multiplication avalanche detector,an RF amplification of 10 dB is observed relative to a Ge PIN linear detector.An all-silicon defect-mediated avalanche photodetector is shown to have a 3 dB RF amplification compared to the same PIN detector.All ring delay measurement results are validated by full-wave simulation.Additionally,the impact of photodetector biasing and system linearity is analyzed.展开更多
Real-time spectrum sensing is essential to enable dynamic and rapid spectrum sharing of unused frequencies to cater the substantial demands of new wireless services deploying the existing RF bands.In this paper,we pre...Real-time spectrum sensing is essential to enable dynamic and rapid spectrum sharing of unused frequencies to cater the substantial demands of new wireless services deploying the existing RF bands.In this paper,we present a novel,real-time spectrum sensing approach for widely used RF signals based on Brillouin-scattering-induced transparency(BIT).A temporal discrimination of multi-channel input frequencies is achieved through the group delay tuning by BIT.By tuning the pump power and frequency,the proposed technique is fully reconfigurable and viable for a broad range of spectrum sensing.Several experimental illustrations of the time domain sensing are presented for two-tone channels with 0.9,1.8,and 5 GHz frequencies to detect the unused spectrum within 3 G,4 G,and 5 G signals.展开更多
基金McDonald Detwiler AssociatesNational Research Council Canada+1 种基金MitacsHTSN Program.
文摘A compact time delay unit is fundamental to integrated photonic circuits with applications in,for example,optical beam-forming networks,photonic equalization,and finite and infinite impulse response optical filtering.In this paper,we report a novel gain-enabled delay readout system using a tunable optical carrier,low-frequency RF signal and CMOS-compatible photodetectors,suitable for silicon photonic integration.The characterization method relies on direct phase measurement of an input RF signal and thereafter extraction of the delay profile.Both integrated silicon and germanium photodetectors coupled with low-bandwidth electronics are used to characterize a microring resonator-based,true-time delay unit under distinct ring–bus coupling formats.The detectors,used in both linear and avalanche mode,are shown to be successful as optical-to-electrical converters and RF amplifiers without introducing significant phase distortion.For a Si–Ge separate-absorption-charge-multiplication avalanche detector,an RF amplification of 10 dB is observed relative to a Ge PIN linear detector.An all-silicon defect-mediated avalanche photodetector is shown to have a 3 dB RF amplification compared to the same PIN detector.All ring delay measurement results are validated by full-wave simulation.Additionally,the impact of photodetector biasing and system linearity is analyzed.
基金Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)(322402243,403154102,424608109,424608271,424608946,424608191)Niedersachsisches Vorab(NL–4 Project“QUANOMET”)。
文摘Real-time spectrum sensing is essential to enable dynamic and rapid spectrum sharing of unused frequencies to cater the substantial demands of new wireless services deploying the existing RF bands.In this paper,we present a novel,real-time spectrum sensing approach for widely used RF signals based on Brillouin-scattering-induced transparency(BIT).A temporal discrimination of multi-channel input frequencies is achieved through the group delay tuning by BIT.By tuning the pump power and frequency,the proposed technique is fully reconfigurable and viable for a broad range of spectrum sensing.Several experimental illustrations of the time domain sensing are presented for two-tone channels with 0.9,1.8,and 5 GHz frequencies to detect the unused spectrum within 3 G,4 G,and 5 G signals.
