Propagation characteristics of finite Airy-Gaussian beams through an apertured misaligned first-order ABCD optical system are studied. In this work, the generalized Huygens-Fresnel diffraction integral and the expansi...Propagation characteristics of finite Airy-Gaussian beams through an apertured misaligned first-order ABCD optical system are studied. In this work, the generalized Huygens-Fresnel diffraction integral and the expansion of the hard aperture function into a finite sum of complex Gaussian functions are used. The propagation of Airy-Gaussian beam passing through: an unapertured misaligned optical system, an apertured aligned ABCD optical system and an unapertured aligned ABCD optical system are derived here as particular cases of the main finding. Some numerical simulations are performed in the paper.展开更多
This paper studies the focusing properties of Gaussian Schell-model （GSM） beams by an astigmatic aperture lens. It is shown that the axial irradiance distribution, the maximum axial irradiance and its position of fo...This paper studies the focusing properties of Gaussian Schell-model （GSM） beams by an astigmatic aperture lens. It is shown that the axial irradiance distribution, the maximum axial irradiance and its position of focused GSM beams by an astigmatic aperture lens depend upon the astigmatism of the lens, the coherence of partially coherent light, the truncation parameter of the aperture and Fresnel number. The numerical calculation results are given to illustrate how these parameters affect the focusing property.展开更多
Gaussian beam expansion based on the aperture field distribution is studied systematically in this paper. The beam series representation for a radiated field and its asymptotic form are derived and applied to aperture...Gaussian beam expansion based on the aperture field distribution is studied systematically in this paper. The beam series representation for a radiated field and its asymptotic form are derived and applied to aperture analysis. Numerical results indicate that this method is able to analyze the radiated field accurately in all zones.展开更多
The approximate analytical expressions of the apertured broadband beams in the far field with Gaussian and Laguerre-Gaussian spatial modes are presented. For the radially polarized Laguerre-Gaussian beam, the result r...The approximate analytical expressions of the apertured broadband beams in the far field with Gaussian and Laguerre-Gaussian spatial modes are presented. For the radially polarized Laguerre-Gaussian beam, the result reveals that the electromagnetic field in the far field is transverse magnetic. The influences of bandwidth （Г） and truncation parameter （Co） on the transverse intensity distribution of the Gaussian beam and on the energy flux distribution of radially polarized Laguerre-Gaussian beam are analysed.展开更多
This paper establishes the classic linear model of signal of the MIMO radar system with distributed apertures. Based on this model, the design principle and detection performance of MIMO radar detector is investigated...This paper establishes the classic linear model of signal of the MIMO radar system with distributed apertures. Based on this model, the design principle and detection performance of MIMO radar detector is investigated under conditions of Gaussian colored noise and partially correlated observation channels. First, the research on design principle of detector shows that the clutter suppression and matched filtering can be independently implemented at each receiving aperture, which greatly reduces the difficulty in implementation of these detectors. Based on these results, a Max detector is proposed for the case where partial channels are disabled due to strong noise and stealth techniques. The second part is the performance analysis of detector. The Fishier divergence coefficient and the statistical equivalent decomposition of limit statistics are used to theoretically analyze the detection performance of AMF detector, and then the analytical expressions of the detection performance of the AMF detector is derived. Analysis results show that both the colored nature of noise and the correlation among observation channels can reduce the capability of spatial diversity of the MIMO radar system, change the target RCSs among observation channels from quick fluctuation to slow fluctuation, and degenerate the detection performance of this radar system into that of the phased array radar system at high signal-to-noise ratio.展开更多
文摘Propagation characteristics of finite Airy-Gaussian beams through an apertured misaligned first-order ABCD optical system are studied. In this work, the generalized Huygens-Fresnel diffraction integral and the expansion of the hard aperture function into a finite sum of complex Gaussian functions are used. The propagation of Airy-Gaussian beam passing through: an unapertured misaligned optical system, an apertured aligned ABCD optical system and an unapertured aligned ABCD optical system are derived here as particular cases of the main finding. Some numerical simulations are performed in the paper.
基金Project supported by the Natural Science Foundation of Henan Province, China （Grant No 0611054000）.
文摘This paper studies the focusing properties of Gaussian Schell-model （GSM） beams by an astigmatic aperture lens. It is shown that the axial irradiance distribution, the maximum axial irradiance and its position of focused GSM beams by an astigmatic aperture lens depend upon the astigmatism of the lens, the coherence of partially coherent light, the truncation parameter of the aperture and Fresnel number. The numerical calculation results are given to illustrate how these parameters affect the focusing property.
文摘Gaussian beam expansion based on the aperture field distribution is studied systematically in this paper. The beam series representation for a radiated field and its asymptotic form are derived and applied to aperture analysis. Numerical results indicate that this method is able to analyze the radiated field accurately in all zones.
基金supported by the Doctorial Start-up Fund of Hengyang Normal University,China (Grant No. 09B06)the Natural Science Foundation of Hunan Province,China (Grant No. 08jj3001)
文摘The approximate analytical expressions of the apertured broadband beams in the far field with Gaussian and Laguerre-Gaussian spatial modes are presented. For the radially polarized Laguerre-Gaussian beam, the result reveals that the electromagnetic field in the far field is transverse magnetic. The influences of bandwidth （Г） and truncation parameter （Co） on the transverse intensity distribution of the Gaussian beam and on the energy flux distribution of radially polarized Laguerre-Gaussian beam are analysed.
基金the Program for New Century Excellent Talents (Grant No. NCET-05-0912)the National Natural Science Foundation of China (Grant Nos. 60672140, 60802088)
文摘This paper establishes the classic linear model of signal of the MIMO radar system with distributed apertures. Based on this model, the design principle and detection performance of MIMO radar detector is investigated under conditions of Gaussian colored noise and partially correlated observation channels. First, the research on design principle of detector shows that the clutter suppression and matched filtering can be independently implemented at each receiving aperture, which greatly reduces the difficulty in implementation of these detectors. Based on these results, a Max detector is proposed for the case where partial channels are disabled due to strong noise and stealth techniques. The second part is the performance analysis of detector. The Fishier divergence coefficient and the statistical equivalent decomposition of limit statistics are used to theoretically analyze the detection performance of AMF detector, and then the analytical expressions of the detection performance of the AMF detector is derived. Analysis results show that both the colored nature of noise and the correlation among observation channels can reduce the capability of spatial diversity of the MIMO radar system, change the target RCSs among observation channels from quick fluctuation to slow fluctuation, and degenerate the detection performance of this radar system into that of the phased array radar system at high signal-to-noise ratio.
