Accurate isotope shift factors of the 2s2p^（3,1）P_1~o–2s^2 ~1S_0 transitions in B II, obtained with the multi-configuration Dirac–Hartree–Fock and the relativistic configuration interaction methods, are reported....Accurate isotope shift factors of the 2s2p^（3,1）P_1~o–2s^2 ~1S_0 transitions in B II, obtained with the multi-configuration Dirac–Hartree–Fock and the relativistic configuration interaction methods, are reported. We found a linear correlation relation between the mass shift factors and the energies for the transitions concerned, considering all-order electron correlations. This relation is important for estimating the uncertainty in the calculation of isotope shift factors. These atomic data can be used to extract the nuclear mean-square charge radii of the boron isotopes with halo structures or to resolve the high precise spectroscopy of B II in astronomical observation.展开更多
Ultra-compact multifunctional integrated photonic modules have great practical significance to photonic integrated circuits (PICs).However,the design effect and efficiency of the existing mainstream inverse design alg...Ultra-compact multifunctional integrated photonic modules have great practical significance to photonic integrated circuits (PICs).However,the design effect and efficiency of the existing mainstream inverse design algorithms are incompetent when designing these modules.We analyze their shortcomings in this task,and propose a new,to our knowledge,inverse design algorithm named polygon search (PS) algorithm to address these problems.We utilize the PS algorithm to design an integrated dual-channel mode-conversion-crossing waveguide module.This module integrates three functions:interconversion between TE_(0) and TE_(1),interconversion between TE_(0) and TE_(2),and channel crossing within only a 4μm×4μm footprint,and its performance is verified by experimental testing.It not only greatly reduces the total footprint of many PICs but also greatly improves their fabricating robustness.Furthermore,we propose a PS-designed mode mixer and a PS-designed bending waveguide,and connect them with the integrated modules to form a four-channel crossing-mode-division-multiplexing system.This system can provide multiple modes on the basis of channel crossing and transmit the output signal in the same direction in parallel within a single output waveguide,which significantly increases the communication bandwidth and decreases the footprint of PICs.At last,we demonstrate the effect and efficiency advantages of the PS algorithm over several mainstream inverse design algorithms by a comprehensive contrast experiment and explain these advantages in theory from several perspectives.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91436103,11404025,and 91536106)the Research Program of National University of Defense Technology,China(Grant No.JC15-0203)the China Postdoctoral Science Foundation(Grant No.2014M560061)
文摘Accurate isotope shift factors of the 2s2p^（3,1）P_1~o–2s^2 ~1S_0 transitions in B II, obtained with the multi-configuration Dirac–Hartree–Fock and the relativistic configuration interaction methods, are reported. We found a linear correlation relation between the mass shift factors and the energies for the transitions concerned, considering all-order electron correlations. This relation is important for estimating the uncertainty in the calculation of isotope shift factors. These atomic data can be used to extract the nuclear mean-square charge radii of the boron isotopes with halo structures or to resolve the high precise spectroscopy of B II in astronomical observation.
基金National Key Research and Development Program of China (2022YFF0706005)National Natural Science Foundation of China (12272407, 60907003,61805278, 62205376, 62275269, 62275271, 62305387)+4 种基金China Postdoctoral Science Foundation (2018M633704)Foundation of NUDT (JC13-02-13, ZK17-03-01)Program for New Century Excellent Talents in University (NCET-12-0142)Postgraduate Scientific Research Innovation Project of Hunan Province,China (CX20230009)Natural Science Foundation of Hunan Province (13JJ3001, 2022JJ40552)。
文摘Ultra-compact multifunctional integrated photonic modules have great practical significance to photonic integrated circuits (PICs).However,the design effect and efficiency of the existing mainstream inverse design algorithms are incompetent when designing these modules.We analyze their shortcomings in this task,and propose a new,to our knowledge,inverse design algorithm named polygon search (PS) algorithm to address these problems.We utilize the PS algorithm to design an integrated dual-channel mode-conversion-crossing waveguide module.This module integrates three functions:interconversion between TE_(0) and TE_(1),interconversion between TE_(0) and TE_(2),and channel crossing within only a 4μm×4μm footprint,and its performance is verified by experimental testing.It not only greatly reduces the total footprint of many PICs but also greatly improves their fabricating robustness.Furthermore,we propose a PS-designed mode mixer and a PS-designed bending waveguide,and connect them with the integrated modules to form a four-channel crossing-mode-division-multiplexing system.This system can provide multiple modes on the basis of channel crossing and transmit the output signal in the same direction in parallel within a single output waveguide,which significantly increases the communication bandwidth and decreases the footprint of PICs.At last,we demonstrate the effect and efficiency advantages of the PS algorithm over several mainstream inverse design algorithms by a comprehensive contrast experiment and explain these advantages in theory from several perspectives.
