Astronomical observation by 2-meter telescope based on liquid crystal adaptive optics with phase diversity

Wu, Daosheng; Yang, Chengliang; Li, Hao; Zhang, Peiguang; Zhang, Xingyun; Cao, Zhaoliang; Mu, Quanquan; Li, Xuan

doi:10.1016/j.optcom.2019.01.036

Cited by 5 publications

(2 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, PD technology is particularly suitable for spatial target imaging applications. PD technique has been extensively investigated by many foreign [4,5] and domestic [6,7] institutions. In 1996 Carreras applied the PD technique to the Beam Directional Telescope and successfully recovered a clear image of the double star μ Scorpio with an angular separation of 1.1″ [8] .…”

Section: Introductionmentioning

confidence: 99%

A fast non-local means algorithm for phase diversity technique to reconstruct high-resolution multi-aperture images

Zhang,

Zhao,

Yang

et al. 2023

Advanced Optical Imaging Technologies VI

View full text Add to dashboard Cite

Phase diversity technique (PD) can jointly estimate the wavefront aberration and the target image of an optical imaging system. The PD technique reconstructs images by acquiring a focal plane image of optical system and one or more images with known aberrations (often selected defocus). Due to the simple construction of the optical system, the ability to detect discontinuous co-phase errors, and its applicability to both point sources and extended targets, The PD technique is uniquely suited for spatial target imaging applications, especially for the detection of multi-aperture piston errors. However, in a spatially low-illumination environment, Poisson noise as the main noise source of the imaging system seriously affects the accuracy of the reconstructed images. In this paper, we propose a method of phase diversity technique based on a fast Non-local Means (NLM) algorithm for reconstructing single-aperture images or multi-aperture images. For the two cases of single-aperture imaging and multi-aperture imaging with piston errors in spatial low illumination conditions, the method is used to solve the sensitivity problem of Poisson noise during image reconstruction. Numerical simulation results show that our method has significant improvement in structural similarity of the recovered images compared with the traditional phase diversity technique, and also is faster than the common non-local mean algorithm. The combination of this fast non-local means algorithm which using integral images and the phase diversity technique greatly reduce the computation time. The field experimental results and simulation results show good agreement. The new method would be useful in the AO system with active Poisson noise.

show abstract

Section: Introductionmentioning

confidence: 99%

A fast non-local means algorithm for phase diversity technique to reconstruct high-resolution multi-aperture images

Zhang,

Zhao,

Yang

et al. 2023

Advanced Optical Imaging Technologies VI

View full text Add to dashboard Cite

show abstract

“…The operating mode of optical components based on liquid crystal can realize full parameter modulation of amplitude, phase, polarization and frequency [1][2][3], it is widely used in liquid crystal display, holographic imaging, hyperspectral imaging, adaptive optics and other imaging fields [4][5][6][7]. In addition, it is also widely used in the field of high-power laser.…”

Section: Introductionmentioning

confidence: 99%

Laser damage resistance analysis of liquid crystal devices based on ITO or GaN transparent electrode

Huang

Cheng

et al. 2022

Thirteenth International Conference on Information Optics and Photonics (CIOP 2022)

View full text Add to dashboard Cite

In this paper, in order to provide theoretical support for the higher laser damage resistant Optically-Addressable liquid crystal Light Valve (OALV) technology research, the laser damage model of liquid crystal optical devices under high power laser is established, and the damage characteristics of optically addressed spatial light modulators based on Si-doped gallium nitride (GaN) electrode and based on indium tin oxide (ITO) electrode are researched. Their thermal distribution and thermal stress under high power laser are analyzed respectively. The results show that the laser damage threshold of liquid crystal device with ITO electrode is only 500 mJ/cm 2 , and the GaN electrode is several times larger than the former under pulse laser irradiation, the electrode of both liquid crystal devices are damaged first. Under the irradiation of high average power laser, the liquid crystal device of ITO electrode will reach the clear point first because of the thermal deposition. However, in liquid crystal devices with GaN electrode, the temperature rise of liquid crystal is small and the temperature distribution is uniform. GaN electrode has better thermal stability than ITO electrode under cooling measures. This undoubtedly shows that liquid crystal optical devices with GaN electrode have a good development potential in high power laser systems.

show abstract

Single-shot quasi-phase-diversity wavefront sensing with a Fibonacci zone-plate module

Zhang

et al. 2023

Applied Physics Letters

View full text Add to dashboard Cite

The phase-diversity wavefront sensor is a popular means for conducting quantitative wavefront measurements and image restoration from several desired intensity measurements. It has wide applications ranging from adaptive optics in telescopes to optical detection in high-power laser systems. In contrast to traditional phase diversity, we propose a modified version of single-shot quasi-phase-diversity wavefront sensing using a multifocal Fibonacci zone-plate module. The Fibonacci zone plate, designed to generate a specific separation distance between the in-focus and defocused diffraction planes, enables recording multiplanar diffraction patterns at a given position under a single exposure. Thus, this modified wavefront sensing can improve recovery accuracy and realize real-time measurements via a single exposure. In our experiment, a test object fabricated on a chrome plate was measured to verify the validity of the proposed single-shot quasi-phase-diversity wavefront sensing. With the advantages of simple real-time operation and improved measurement accuracy, this technique can be applied to various detection and imaging processes, such as wavefront measurements and image restoration.

show abstract

Astronomical observation by 2-meter telescope based on liquid crystal adaptive optics with phase diversity

Cited by 5 publications

References 17 publications

A fast non-local means algorithm for phase diversity technique to reconstruct high-resolution multi-aperture images

A fast non-local means algorithm for phase diversity technique to reconstruct high-resolution multi-aperture images

Laser damage resistance analysis of liquid crystal devices based on ITO or GaN transparent electrode

Single-shot quasi-phase-diversity wavefront sensing with a Fibonacci zone-plate module

Contact Info

Product

Resources

About