In this paper, we propose and demonstrate an improvement of plenoptic imaging configuration for high resolution imaging with wide field of view in turbulent atmosphere. For the improvement, the plenoptic imaging configuration is equipped with a high resolution conventional imaging system. Plenoptic imaging system is only used for measuring the wavefront distortion of imaging beams. Based on wavefront distortions measured by plenoptic imaging system and blurred images captured by the conventional imaging system, high resolution images can be achieved by the deconvolution of blurred images. Numerical simulations and experimental results show that the improved plenoptic imaging configuration can be used for restoration of near-diffraction-limited images of objects, successfully. Compared with conventional imaging system and plenoptic imaging system, the improved plenoptic imaging configuration combines advantages of wavefront distortion correction, high resolution imaging, wide field of view. The technology proposed in this paper can have wide applications in photo-electric theodolite and large telescopes.
The Performance of wavefront aberration detection and recovery, is limited by the spatial resolution in subaperture, especially for the high-order aberration. To improve the accuracy of wavefront reconstruction, our paper focuses more on the phase retrieval using the stochastic parallel gradient descent (SPGD) algorithm with lower subaperture. In this paper, the theoretical that Shack-Hartmann wavefront sensor can get a single subaperture high spatial frequency components, which are four-dimensional spatial position and spatial frequency information of the two-dimensional light field is researched.Numerical simulations show that compared with conventional methods, the SPGD algorithm can effectively improve the phase retrieval precision of higher-order aberrations, and decrease the influence of the spatial resolution in subaperture. At the same time, by selecting the appropriate algorithm iterative initial value can effectively enhance the speed of wave front reconstruction.
To take advantage of the large-diameter telescope for high-resolution imaging of extended targets, it is necessary to detect and compensate the wave-front aberrations induced by atmospheric turbulence. Data recorded by Plenoptic cameras can be used to extract the wave-front phases associated to the atmospheric turbulence in an astronomical observation. In order to recover the wave-front phase tomographically, a method of completing the large Field Of View (FOV), multi-perspective wave-front detection simultaneously is urgently demanded, and it is plenoptic camera that possesses this unique advantage. Our paper focuses more on the capability of plenoptic camera to extract the wave-front from different perspectives simultaneously. In this paper, we built up the corresponding theoretical model and simulation system to discuss wave-front measurement characteristics utilizing plenoptic camera as wave-front sensor. And we evaluated the performance of plenoptic camera with different types of wave-front aberration corresponding to the occasions of applications. In the last, we performed the multi-perspective wave-front sensing employing plenoptic camera as wave-front sensor in the simulation. Our research of wave-front measurement characteristics employing plenoptic camera is helpful to select and design the parameters of a plenoptic camera, when utilizing which as multi-perspective and large FOV wave-front sensor, which is expected to solve the problem of large FOV wave-front detection, and can be used for AO in giant telescopes.
To overcome the shortcomings of Shack-Hartmann wavefront sensor, we developed a lightfield wavefront detection system,
which is able to complete the large field of view, multi-perspective wavefront detection in a single photographic exposure.
The lightfield wavefront detection system includes an imaging primary mirror, a lenslet array and a photosensitive device.
The lenslet array is located on the imaging plane of the imaging primary mirror and the photosensitive device is located on
the focal plane of the lenslet array. In this system, each lenslet reimages the aperture and forms a low-resolution image of
the aperture. Compared with the Shack-Hartmann sensor, this lightfield measuring method can obtain imaging arrays in
different perspectives. By comparing the array information with the standard information, we can obtain the slope matrix of
the wavefront in different perspectives and restore the wavefront in a large field of view. Based on Fourier optics, we built
the corresponding theoretical model and simulation system. By busing Meade telescope, turbulent phase screen, lenslet
array and CCD camera, we founded the experimental lightfield wavefront measuring system. Numerical simulation results
and experimental results show that this wavefront measuring method can effectively achieve the wavefront aberration
information. This wavefront measurement method can realize the multi-perspective wavefront measurement, which is
expected to solve the problem of large viewing field wavefront detection, and can be used for adaptive optics in giant
telescopes.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.