Considering the pivotal role of single-wavelength anomalous diffraction(SAD) in macromolecular crystallography,our objective was to introduce DSAS,a novel program designed for efficient anomalous scattering substructu...Considering the pivotal role of single-wavelength anomalous diffraction(SAD) in macromolecular crystallography,our objective was to introduce DSAS,a novel program designed for efficient anomalous scattering substructure determination.DSAS stands out with its core components:a modified phase-retrieval algorithm and automated parameter tuning.The software boasts an intuitive graphical user interface(GUI),facilitating seamless input of essential data and real-time monitoring.Extensive testing on DSAS has involved diverse datasets,encompassing proteins,nucleic acids,and various anomalous scatters such as sulfur(S),selenium(Se),metals,and halogens.The results confirm DSAS’s exceptional performance in accurately determining heavy atom positions,making it a highly effective tool in the field.展开更多
The carrier-free phase-retrieval(CF-PR)receiver can reconstruct the optical field information only from two de-correlated intensity measurements without the involvement of a continuous-wave optical carrier.Here,we pro...The carrier-free phase-retrieval(CF-PR)receiver can reconstruct the optical field information only from two de-correlated intensity measurements without the involvement of a continuous-wave optical carrier.Here,we propose a digital subcarrier multiplexing(DSM)-enabled CF-PR receiver with hardware-efficient and modulation format-transparent merits.By numerically retrieving the optical field information of 56 GBaud DSM signals with QPSK/16QAM/32QAM modulation after 80-km standard single-mode fiber(SSMF)transmission,we identify that the DSM enabled CF-PR receiver is beneficial in reducing the implementation complexity of the CF-PR process,in comparison with the traditional single-carrier counterpart,because the lower symbol rate of each subcarrier is helpful in reducing the implementation complexity of multiple chromatic dispersion compensations and emulations during the PR iteration.Moreover,the DSM-enabled CF-PR receiver is verified to be robust toward various transmission imperfections,including transmitter-side laser linewidth and its wavelength drift,receiver-side time skew,and amplitude imbalance between two intensity tributaries.Finally,the superiority of the DSM-enabled CF-PR receiver is experimentally verified by recovering the optical field information of 25 GBaud 16QAM signals,after 40-km SSMF transmission for the first time.Thus,the DSM-enabled CF-PR receiver is promising for high-capacity photonic interconnection with direct detection.展开更多
Imaging through scattering media remains a formidable challenge in optical imaging.Exploiting the memory effect presents new opportunities for non-invasive imaging through the scattering medium by leveraging speckle c...Imaging through scattering media remains a formidable challenge in optical imaging.Exploiting the memory effect presents new opportunities for non-invasive imaging through the scattering medium by leveraging speckle correlations.Traditional speckle correlation imaging often utilizes a random phase as the initial phase,leading to challenges such as convergence to incorrect local minima and the inability to resolve ambiguities in object orientation.Here,a novel method for high-quality reconstruction of single-shot scattering imaging is proposed.By employing the initial phase obtained from bispectral analysis in the subsequent phase retrieval algorithm,the convergence and accuracy of the reconstruction process are notably improved.Furthermore,a robust search technique based on an image clarity evaluation function successfully determines the optimal reconstruction size.The study demonstrates that the proposed method can obtain high-quality reconstructed images compared with the existing scattering imaging approaches.This innovative approach to non-invasive single-shot imaging through strongly scattering media shows potential for applications in scenarios involving moving objects or dynamic scattering imaging scenes.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.32371280 and T2350011)。
文摘Considering the pivotal role of single-wavelength anomalous diffraction(SAD) in macromolecular crystallography,our objective was to introduce DSAS,a novel program designed for efficient anomalous scattering substructure determination.DSAS stands out with its core components:a modified phase-retrieval algorithm and automated parameter tuning.The software boasts an intuitive graphical user interface(GUI),facilitating seamless input of essential data and real-time monitoring.Extensive testing on DSAS has involved diverse datasets,encompassing proteins,nucleic acids,and various anomalous scatters such as sulfur(S),selenium(Se),metals,and halogens.The results confirm DSAS’s exceptional performance in accurately determining heavy atom positions,making it a highly effective tool in the field.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFB2900702)the National Natural Science Foundation of China(Grant No.U21A20506)the Guangdong Introducing Innovative and Entrepreneurial Teams of“The Pearl River Talent Recruitment Program”(Grant No.2021ZT09X044).
文摘The carrier-free phase-retrieval(CF-PR)receiver can reconstruct the optical field information only from two de-correlated intensity measurements without the involvement of a continuous-wave optical carrier.Here,we propose a digital subcarrier multiplexing(DSM)-enabled CF-PR receiver with hardware-efficient and modulation format-transparent merits.By numerically retrieving the optical field information of 56 GBaud DSM signals with QPSK/16QAM/32QAM modulation after 80-km standard single-mode fiber(SSMF)transmission,we identify that the DSM enabled CF-PR receiver is beneficial in reducing the implementation complexity of the CF-PR process,in comparison with the traditional single-carrier counterpart,because the lower symbol rate of each subcarrier is helpful in reducing the implementation complexity of multiple chromatic dispersion compensations and emulations during the PR iteration.Moreover,the DSM-enabled CF-PR receiver is verified to be robust toward various transmission imperfections,including transmitter-side laser linewidth and its wavelength drift,receiver-side time skew,and amplitude imbalance between two intensity tributaries.Finally,the superiority of the DSM-enabled CF-PR receiver is experimentally verified by recovering the optical field information of 25 GBaud 16QAM signals,after 40-km SSMF transmission for the first time.Thus,the DSM-enabled CF-PR receiver is promising for high-capacity photonic interconnection with direct detection.
基金supported by the National Natural Science Foundation of China(Nos.62305220 and 92050202)the Shanghai Sailing Program(No.23YF1429300).
文摘Imaging through scattering media remains a formidable challenge in optical imaging.Exploiting the memory effect presents new opportunities for non-invasive imaging through the scattering medium by leveraging speckle correlations.Traditional speckle correlation imaging often utilizes a random phase as the initial phase,leading to challenges such as convergence to incorrect local minima and the inability to resolve ambiguities in object orientation.Here,a novel method for high-quality reconstruction of single-shot scattering imaging is proposed.By employing the initial phase obtained from bispectral analysis in the subsequent phase retrieval algorithm,the convergence and accuracy of the reconstruction process are notably improved.Furthermore,a robust search technique based on an image clarity evaluation function successfully determines the optimal reconstruction size.The study demonstrates that the proposed method can obtain high-quality reconstructed images compared with the existing scattering imaging approaches.This innovative approach to non-invasive single-shot imaging through strongly scattering media shows potential for applications in scenarios involving moving objects or dynamic scattering imaging scenes.
