High-contrast imaging coronagraphs, used for the detection of exoplanets, have always adopted passive coronagraph optical components. It is therefore impossible to actively optimize the coronagraphs to achieve their b...High-contrast imaging coronagraphs, used for the detection of exoplanets, have always adopted passive coronagraph optical components. It is therefore impossible to actively optimize the coronagraphs to achieve their best performance. To solve this problem, we propose a novel high-contrast imaging coronagraph which combines a liquid crystal array （LCA） for active pupil apodization and a deformable mirror （DM） for phase correction. The LCA we use is an amplitude-only spatial light mod- ulator. The LCA is well calibrated and compensates for its amplitude non-uniformity and nonlinear intensity responsivity. We measured the imaging contrasts of the coron- agraph system with the LCA only and without the DM deployed. Imaging contrasts of 10-4 and 10-5 can be reached at an inner working angular distance of 2.5 and 5A/D, respectively. A simulation shows that the phase errors on the coronagraph pupil limit the contrast performance. The contrast could be further improved if a DM is deployed to correct the phase errors induced by the LCA and coronagraph optics.展开更多
In order to improve depth extraction accuracy, a method using moving array lenslet technique(MALT) in pickup stage is proposed, which can decrease the depth interval caused by pixelation. In this method, the lenslet a...In order to improve depth extraction accuracy, a method using moving array lenslet technique(MALT) in pickup stage is proposed, which can decrease the depth interval caused by pixelation. In this method, the lenslet array is moved along the horizontal and vertical directions simultaneously for N times in a pitch to get N sets of elemental images. Computational integral imaging reconstruction method for MALT is taken to obtain the slice images of the 3 D scene, and the sum modulus(SMD) blur metric is taken on these slice images to achieve the depth information of the 3 D scene. Simulation and optical experiments are carried out to verify the feasibility of this method.展开更多
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences(Grant No.XDA04070600)the National Natural Science Foundation of China(Grant Nos.11003031 and 10873024)+1 种基金as well as the National Astronomical Observatories' Special Fund for Astronomy-2009Part of the work described in this paper was carried out at California State University Northridge,with support from the National Science Foundation under Grant ATM-0841440
文摘High-contrast imaging coronagraphs, used for the detection of exoplanets, have always adopted passive coronagraph optical components. It is therefore impossible to actively optimize the coronagraphs to achieve their best performance. To solve this problem, we propose a novel high-contrast imaging coronagraph which combines a liquid crystal array （LCA） for active pupil apodization and a deformable mirror （DM） for phase correction. The LCA we use is an amplitude-only spatial light mod- ulator. The LCA is well calibrated and compensates for its amplitude non-uniformity and nonlinear intensity responsivity. We measured the imaging contrasts of the coron- agraph system with the LCA only and without the DM deployed. Imaging contrasts of 10-4 and 10-5 can be reached at an inner working angular distance of 2.5 and 5A/D, respectively. A simulation shows that the phase errors on the coronagraph pupil limit the contrast performance. The contrast could be further improved if a DM is deployed to correct the phase errors induced by the LCA and coronagraph optics.
基金supported by the National Natural Science Foundation of China(Nos.11474169 and 61675100)the Tianjin Natural Science Foundation(No.15JCYBJC16900)
文摘In order to improve depth extraction accuracy, a method using moving array lenslet technique(MALT) in pickup stage is proposed, which can decrease the depth interval caused by pixelation. In this method, the lenslet array is moved along the horizontal and vertical directions simultaneously for N times in a pitch to get N sets of elemental images. Computational integral imaging reconstruction method for MALT is taken to obtain the slice images of the 3 D scene, and the sum modulus(SMD) blur metric is taken on these slice images to achieve the depth information of the 3 D scene. Simulation and optical experiments are carried out to verify the feasibility of this method.
