High resolution test for large optics with sub-pixel phase retrieval method

2007 ◽  
Author(s):  
Xiaojun Hu ◽  
Shengyi Li ◽  
Yulie Wu
Keyword(s):  
High Resolution ◽  
Phase Retrieval ◽  
Retrieval Method

scholarly journals Measurement of Small-Slope Free-Form Optical Surfaces with the Modified Phase Retrieval

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 82
Author(s):  
Xinxue Ma ◽  
Jianli Wang ◽  
Bin Wang ◽  
Xinyue Liu
Keyword(s):  
Wave Front ◽  
Phase Retrieval ◽  
Computation Time ◽  
Experimental Arrangement ◽  
Free Form ◽  
Retrieval Algorithm ◽  
Retrieval Method ◽  
Optical Surfaces ◽  
Image Capturing ◽  
Phase Retrieval Algorithm

In this paper, we demonstrate the use of the modified phase retrieval as a method for application in the measurement of small-slope free-form optical surfaces. This technique is a solution for the measurement of small-slope free-form optical surfaces, based on the modified phase retrieval algorithm, whose essence is that only two defocused images are needed to estimate the wave front with an accuracy similar to that of the traditional phase retrieval but with less image capturing and computation time. An experimental arrangement used to measure the small-slope free-form optical surfaces using the modified phase retrieval is described. The results of these experiments demonstrate that the modified phase retrieval method can achieve measurements comparable to those of the standard interferometer.

scholarly journals Two-Step Phase Retrieval Algorithm Using Single-Intensity Measurement

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Cheng Zhang ◽  
Meiqin Wang ◽  
Qianwen Chen ◽  
Dong Wang ◽  
Sui Wei
Keyword(s):  
Phase Retrieval ◽  
Fourier Spectrum ◽  
Retrieval Algorithm ◽  
Improved Method ◽  
Retrieval Method ◽  
Intensity Measurements ◽  
Successful Recovery ◽  
Reconstruction Quality ◽  
Low Probability ◽  
Phase Retrieval Algorithm

Aiming at the problem that the single-intensity phase retrieval method has poor reconstruction quality and low probability of successful recovery, an improved method is proposed in this paper. Our method divides the phase retrieval into two steps: firstly, the GS algorithm is used to recover the amplitude in the spatial domain from the single-spread Fourier spectrum, and then the classical GS algorithm using two intensity measurements (one is recorded and the other is estimated from the first step) measurements is used to recover the phase. Finally, the effectiveness of the proposed method is verified by numerical experiments.

scholarly journals Phaseless Terahertz Coded-Aperture Imaging Based on Incoherent Detection

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 226 ◽  
Author(s):  
Long Peng ◽  
Chenggao Luo ◽  
Bin Deng ◽  
Hongqiang Wang ◽  
Yuliang Qin ◽  
...  
Keyword(s):  
High Resolution ◽  
High Speed ◽  
Phase Retrieval ◽  
Time Frame ◽  
Frame Rate ◽  
Future Research ◽  
Coded Aperture ◽  
Main Work ◽  
Coded Aperture Imaging ◽  
The Matrix

In this paper, we propose a phaseless terahertz coded-aperture imaging (PTCAI) method by using a single incoherent detector or an incoherent detection array. We at first analyze and model the system architecture, derive the matrix imaging equation, and then study the phase retrieval techniques to reconstruct the original target with high resolution. Numerical experiments are performed and the results show that the proposed method can significantly reduce the system complexity in the receiving process while maintaining high resolution imaging capability. Furthermore, the approach of using incoherent detection array instead of single detector is capable of decreasing the encoding and sampling times, and therefore helps to improve the imaging frame rate. In our future research, the method proposed in this paper will be experimentally tested and validated, and high-speed PTCAI at nearly real-time frame rates will be the main work.

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