Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（C...Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.展开更多
提出了一种使用介电突起消除边缘场效应的硅基液晶显示器(Liquid Crystal on Silicon,LCoS)。在像素电极之间设计介电突起结构来阻隔相邻像素电极之间的串扰电场,通过对LCoS的液晶分子指向矢分布和边缘场串扰现象进行仿真,分析了边缘场...提出了一种使用介电突起消除边缘场效应的硅基液晶显示器(Liquid Crystal on Silicon,LCoS)。在像素电极之间设计介电突起结构来阻隔相邻像素电极之间的串扰电场,通过对LCoS的液晶分子指向矢分布和边缘场串扰现象进行仿真,分析了边缘场效应产生的机理及其影响因素,并对相应反射率和相位进行了计算和对比。具有介电突起的LCoS相比传统LCoS在减少相邻像素边缘反射率和相位干扰上有明显的效果,反射率始终维持在96%,相位差保持不变,对比度大于35∶1的区域接近60°,整体视角基本不受影响。所提出的介电突起能够很好地消除横向电场对相邻像素内液晶分子取向的影响,进而提高了LCoS的对比度,大大改善了显示效果。展开更多
Most existing light field(LF)super-resolution(SR)methods either fail to fully use angular information or have an unbalanced performance distribution because they use parts of views.To address these issues,we propose a...Most existing light field(LF)super-resolution(SR)methods either fail to fully use angular information or have an unbalanced performance distribution because they use parts of views.To address these issues,we propose a novel integration network based on macro-pixel representation for the LF SR task,named MPIN.Restoring the entire LF image simultaneously,we couple the spatial and angular information by rearranging the four-dimensional LF image into a two-dimensional macro-pixel image.Then,two special convolutions are deployed to extract spatial and angular information,separately.To fully exploit spatial-angular correlations,the integration resblock is designed to merge the two kinds of information for mutual guidance,allowing our method to be angular-coherent.Under the macro-pixel representation,an angular shuffle layer is tailored to improve the spatial resolution of the macro-pixel image,which can effectively avoid aliasing.Extensive experiments on both synthetic and real-world LF datasets demonstrate that our method can achieve better performance than the state-of-the-art methods qualitatively and quantitatively.Moreover,the proposed method has an advantage in preserving the inherent epipolar structures of LF images with a balanced distribution of performance.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11774095,11722431 and 11621404the Shanghai Basic Research Project under Grant No 18JC1412200+2 种基金the National Key R&D Program of China under Grant No2016YFB0400904the Program of Introducing Talents of Discipline to Universities under Grant No B12024the Shanghai International Cooperation Project under Grant No 16520710600
文摘Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.
文摘提出了一种使用介电突起消除边缘场效应的硅基液晶显示器(Liquid Crystal on Silicon,LCoS)。在像素电极之间设计介电突起结构来阻隔相邻像素电极之间的串扰电场,通过对LCoS的液晶分子指向矢分布和边缘场串扰现象进行仿真,分析了边缘场效应产生的机理及其影响因素,并对相应反射率和相位进行了计算和对比。具有介电突起的LCoS相比传统LCoS在减少相邻像素边缘反射率和相位干扰上有明显的效果,反射率始终维持在96%,相位差保持不变,对比度大于35∶1的区域接近60°,整体视角基本不受影响。所提出的介电突起能够很好地消除横向电场对相邻像素内液晶分子取向的影响,进而提高了LCoS的对比度,大大改善了显示效果。
基金Project supported by the National Natural Science Foundation of China(No.61773295)。
文摘Most existing light field(LF)super-resolution(SR)methods either fail to fully use angular information or have an unbalanced performance distribution because they use parts of views.To address these issues,we propose a novel integration network based on macro-pixel representation for the LF SR task,named MPIN.Restoring the entire LF image simultaneously,we couple the spatial and angular information by rearranging the four-dimensional LF image into a two-dimensional macro-pixel image.Then,two special convolutions are deployed to extract spatial and angular information,separately.To fully exploit spatial-angular correlations,the integration resblock is designed to merge the two kinds of information for mutual guidance,allowing our method to be angular-coherent.Under the macro-pixel representation,an angular shuffle layer is tailored to improve the spatial resolution of the macro-pixel image,which can effectively avoid aliasing.Extensive experiments on both synthetic and real-world LF datasets demonstrate that our method can achieve better performance than the state-of-the-art methods qualitatively and quantitatively.Moreover,the proposed method has an advantage in preserving the inherent epipolar structures of LF images with a balanced distribution of performance.
