A new extendable method for the simulation of atmospheric wave-fronts with turbulence intermittency is reported. The purpose is to generate simulations consistent with the distributions observed for the turbulence par...A new extendable method for the simulation of atmospheric wave-fronts with turbulence intermittency is reported. The purpose is to generate simulations consistent with the distributions observed for the turbulence parameters and the seeing, not available with standard methods. The intermittency is included by entering log-normal distributed arrays for the Fried parameter and the spatial coherence outer scale length into an extended form of the phase spectrum. The method is tested on large samples of simulated long-exposure point-source images. The tests show the agreement of the simulations with literature data. The simulations show that the intermittency affects negligibly the long-term median image size but breaks the symmetry of the wave-front phase spectrum, scatters the phase structure function and changes the image profile.展开更多
We developed an adaptive optics system to correct the wave-front distortion of an intense fs laser beam from our multi-TW laser system, Jiguang II. In this paper, the instruments of the adaptive optical system are des...We developed an adaptive optics system to correct the wave-front distortion of an intense fs laser beam from our multi-TW laser system, Jiguang II. In this paper, the instruments of the adaptive optical system are described and the experimental results of the closed-loop wave-front correction are presented. A distorted laser wave-front of 20 wavelengths of P-V values was corrected to 0.15 wavelength of P-V values. The beam quality of the laser system varies from 3.5 diffraction limit to 1.5 diffraction limit.展开更多
In this paper we present the recent research results in the field of vision correction and supernormal vision according to the actual measurements of the wave-front aberrations and the corneal surface topography,the c...In this paper we present the recent research results in the field of vision correction and supernormal vision according to the actual measurements of the wave-front aberrations and the corneal surface topography,the clinical detection of the visual function and the laser corneal refractive surgery,and the optimization of the optical system. These include the features of the aberrations of human eye with different pupil sizes,different fields of view and temporal accommodation,the influence of the polychromatic illumination of the visible wavelength on the supernormal vision,and the effect of the existing laser corneal refractive surgery on the wave-front ab-errations of the eye. It is shown that the wave-front aberration of human eye is of temporal variation and of synthesis with multi impact factors. To achieve super-normal vision,an optimum engineering data for the customized laser corneal sur-gery should be firstly acquired,which may involve the dynamic free-form optical surface. Although the myopia can be corrected by the laser in situ keratomileusis(LASIK) in a certain degree,it brings about negative effects under scotopic condi-tions.展开更多
High-contrast imaging provided by a coronagraph is critical for the direction imaging of the Earth-like planet orbiting its bright parent star.A major limitation for such direct imaging is the speckle noise that is in...High-contrast imaging provided by a coronagraph is critical for the direction imaging of the Earth-like planet orbiting its bright parent star.A major limitation for such direct imaging is the speckle noise that is induced from the wave-front error of an optical system.We derive an algorithm for the wave-front measurement directly from 3 focal plane images.The 3 images are achieved through a deformable mirror to provide specific phases for the optics system.We introduce an extra amplitude modulation on one deformable mirror configuration to create an uncorrelated wave-front,which is a critical procedure for wave-front sensing.The simulation shows that the reconstructed wave-front is consistent with the original wave-front theoretically,which indicates that such an algorithm is a promising technique for the wave-front measurement for the high-contrast imaging.展开更多
宣城发射台中波前端系统标准化改造主要包括信号源线路改造、增设供电数据监测以及不间断电源(Uninterruptible Power Supply,UPS)旁路改造。通过优化信号源线路布局,使其更加安全、美观且合理。基于增设的供电数据监测功能,实时掌握供...宣城发射台中波前端系统标准化改造主要包括信号源线路改造、增设供电数据监测以及不间断电源(Uninterruptible Power Supply,UPS)旁路改造。通过优化信号源线路布局,使其更加安全、美观且合理。基于增设的供电数据监测功能,实时掌握供配电与UPS运行状况,在出现异常时及时发出告警。通过UPS旁路改造,确保在UPS系统出现故障或对设备进行检修时能够自动切换到UPS旁路,便于信号源系统故障排查。展开更多
该文首次报道了一种极简构架的5G毫米波反向阵设计原理及其CMOS芯片实现技术。该毫米波反向阵极简构架,利用次谐波混频器提供相位共轭和阵列反向功能,无需移相电路及波束控制系统,便可实现波束自动回溯移动通信功能。该文采用国产0.18μ...该文首次报道了一种极简构架的5G毫米波反向阵设计原理及其CMOS芯片实现技术。该毫米波反向阵极简构架,利用次谐波混频器提供相位共轭和阵列反向功能,无需移相电路及波束控制系统,便可实现波束自动回溯移动通信功能。该文采用国产0.18μm CMOS工艺研制了5G毫米波反向阵芯片,包括发射前端、接收前端及跟踪锁相环等核心模块,其中发射及接收前端芯片采用次谐波混频及跨导增强等技术,分别实现了19.5 d B和18.7 d B的实测转换增益。所实现的跟踪锁相环芯片具备双模工作优势,可根据不同参考信号支持幅度调制及相位调制,实测输出信号相噪优于–125 dBc/Hz@100 kHz。该文给出的测试结果验证了所提5G毫米波反向阵通信架构及其CMOS芯片实现的可行性,从而为5G/6G毫米波通信探索了一种架构极简、成本极低、拓展性强的新方案。展开更多
文摘A new extendable method for the simulation of atmospheric wave-fronts with turbulence intermittency is reported. The purpose is to generate simulations consistent with the distributions observed for the turbulence parameters and the seeing, not available with standard methods. The intermittency is included by entering log-normal distributed arrays for the Fried parameter and the spatial coherence outer scale length into an extended form of the phase spectrum. The method is tested on large samples of simulated long-exposure point-source images. The tests show the agreement of the simulations with literature data. The simulations show that the intermittency affects negligibly the long-term median image size but breaks the symmetry of the wave-front phase spectrum, scatters the phase structure function and changes the image profile.
基金This work was partly supported by the National Natural Science Foundation of China(Grant Nos.60225005,60308001)the NKBRSF(Grant No.G1999075202)the National Hi-tech ICF program.
文摘We developed an adaptive optics system to correct the wave-front distortion of an intense fs laser beam from our multi-TW laser system, Jiguang II. In this paper, the instruments of the adaptive optical system are described and the experimental results of the closed-loop wave-front correction are presented. A distorted laser wave-front of 20 wavelengths of P-V values was corrected to 0.15 wavelength of P-V values. The beam quality of the laser system varies from 3.5 diffraction limit to 1.5 diffraction limit.
基金Supported by the National Natural Science Foundation of China (Grant No. 60438030)the Key Research Foundation of Scientific and Technical Committee of Tianjin City of China (Grant No. 033183711)
文摘In this paper we present the recent research results in the field of vision correction and supernormal vision according to the actual measurements of the wave-front aberrations and the corneal surface topography,the clinical detection of the visual function and the laser corneal refractive surgery,and the optimization of the optical system. These include the features of the aberrations of human eye with different pupil sizes,different fields of view and temporal accommodation,the influence of the polychromatic illumination of the visible wavelength on the supernormal vision,and the effect of the existing laser corneal refractive surgery on the wave-front ab-errations of the eye. It is shown that the wave-front aberration of human eye is of temporal variation and of synthesis with multi impact factors. To achieve super-normal vision,an optimum engineering data for the customized laser corneal sur-gery should be firstly acquired,which may involve the dynamic free-form optical surface. Although the myopia can be corrected by the laser in situ keratomileusis(LASIK) in a certain degree,it brings about negative effects under scotopic condi-tions.
基金Supported by the National Natural Science Foundation of China (Grant No. 10873024)
文摘High-contrast imaging provided by a coronagraph is critical for the direction imaging of the Earth-like planet orbiting its bright parent star.A major limitation for such direct imaging is the speckle noise that is induced from the wave-front error of an optical system.We derive an algorithm for the wave-front measurement directly from 3 focal plane images.The 3 images are achieved through a deformable mirror to provide specific phases for the optics system.We introduce an extra amplitude modulation on one deformable mirror configuration to create an uncorrelated wave-front,which is a critical procedure for wave-front sensing.The simulation shows that the reconstructed wave-front is consistent with the original wave-front theoretically,which indicates that such an algorithm is a promising technique for the wave-front measurement for the high-contrast imaging.
文摘宣城发射台中波前端系统标准化改造主要包括信号源线路改造、增设供电数据监测以及不间断电源(Uninterruptible Power Supply,UPS)旁路改造。通过优化信号源线路布局,使其更加安全、美观且合理。基于增设的供电数据监测功能,实时掌握供配电与UPS运行状况,在出现异常时及时发出告警。通过UPS旁路改造,确保在UPS系统出现故障或对设备进行检修时能够自动切换到UPS旁路,便于信号源系统故障排查。
文摘该文首次报道了一种极简构架的5G毫米波反向阵设计原理及其CMOS芯片实现技术。该毫米波反向阵极简构架,利用次谐波混频器提供相位共轭和阵列反向功能,无需移相电路及波束控制系统,便可实现波束自动回溯移动通信功能。该文采用国产0.18μm CMOS工艺研制了5G毫米波反向阵芯片,包括发射前端、接收前端及跟踪锁相环等核心模块,其中发射及接收前端芯片采用次谐波混频及跨导增强等技术,分别实现了19.5 d B和18.7 d B的实测转换增益。所实现的跟踪锁相环芯片具备双模工作优势,可根据不同参考信号支持幅度调制及相位调制,实测输出信号相噪优于–125 dBc/Hz@100 kHz。该文给出的测试结果验证了所提5G毫米波反向阵通信架构及其CMOS芯片实现的可行性,从而为5G/6G毫米波通信探索了一种架构极简、成本极低、拓展性强的新方案。
