Adaptive optics (AO) is the technology for correcting the dynamic optical wavefront errors. This article reviews the development process of AO in recent 50 years including: the first stage of development, progresses of United States in the period of "Star War", and the applications of AO in the fields of high resolution imaging of ground-based telescopes, laser systems, especially for inertial confinement fusion (ICF), and ophthalmology. Moreover the development trends of AO are also presented. For each technical innovation, the first published paper of the innovator is cited as far as possible. Giving a development skeleton of AO is the purpose of this paper.

The beam qualities of high power solid-state slab lasers are severely limited by many factors such as thermal effects of the gain medium. Simultaneously achieving high beam quality and high average power remains a fundamental problem in the development of high power lasers. Adaptive optics systems are able to significantly improve beam qualities by compensating for the static and dynamic phase distortions of the laser beams. In recent years, Institute of Optics and Electronics, Chinese Academy of Sciences has developed low-order aberration com- pensators, weighted least-square wavefront reconstruction algorithms, and generic real-time wavefront processors for solid-state slab lasers. Based on these key components, over two dozens of adaptive optics systems are delivered to a variety of solid-state slab laser systems in China for beam cleanup. With effective operations of these adaptive optics systems, the beam qualities of the laser systems have all been well improved.

The advance of satellite to ground laser communication station using adaptive optics (AO) is summarized. Adaptive optics is the dominant technology to solve the atmosphere induced coherence degradation and availability reduction in the USA and Europe researching relay satellites. Key technologies, such as adaptive optics, muti- ground station receiving in day and night，and coherent communication are planned to test in these projects. It indicates that the satellite to ground laser communication is advancing to the engineering application with high date rate coherence and round-the-clock high availability. Several satellite to ground laser communication experiments have been successfully carried out in domestic, and the high availability coherent laser communication test is in progress. Adaptive optics technology has been applied in several ground stations and pretty results are obtained in the preliminary experiment. The related technology progress keeps in the same level with the foreign countries.

In recent years, the coherent beam combining technique for laser transmission in atmosphere has been widely investigated, while the study of this technique’s application in space optical communications is few. In fact, the structure of multi-aperture receiving antenna based on coherent beam combining could be employed to correct the atmospheric turbulence effect and to enhance the performance of the space optical communication system. In the paper, the recent development of coherent beam transmission and control technique for laser transmission application in atmosphere is reviewed. Then, the research progress of fiber-based coherent beam combining in multi- aperture receiving space optical communication system is reported in detail, including the coherent combining based on 3-dB fiber coupler and the coherent polarization combining based on fiber polarization beam combiner, which might have great potential in space optical communication system.

Adaptive optics (AO) techniques allow to measure and manipulate the wavefront aberrations in real time. This technology was first successfully applied to the manipulation of ocular aberrations, and high resolution retinal images and “supernormal vision” were achieved in vivo for the first time in 1997. Subsequently, adaptive optics were developed rapidly in ophthalmology. This field includes two main directions: high resolution imaging of the retina and the research of ocular aberrations manipulation and its influence on visual function. In 2011, professor D. R.Williams from Rochester University and Professor Austin Roorda from California University made two comprehensive overviews on retinal high-resolution imaging and ocular aberrations manipulation and its influence on visual function, respectively. In 1997, reseachers in Institute of Optics and Electronics took the lead in developing of adaptive optics technology in China. This article firstly introduces the principle of ocular adaptive optical system briefly, and then reports the main research progress of Institute of Optics and Electronics in this field for the last five years.

In order to further improve the imaging quality of the adaptive optical system, the widely used image reconstruction technologies at present, including blind deconvolution, phase diversity and speckle imaging, are extensively researched in this paper. The characteristics, application scenes and processing objects of each technology are analyzed in detail and the algorithms are improved reasonably combined with the characteristics of the adaptive optical imaging system. Experimental results of in vivo human retinal cell image and sunspots image, proved that the improved technologies can effectively increase the quality and resolution of adaptive optical images, and satisfy the needs of adaptive optics system for image post-processing.

Solar images with high spatial resolution, high temporal resolution across a large field of view (FoV) are aspired for solar physics and space weather. Ground-based high spatial resolution imaging of the Sun is severely limited by wavefront disturbances induced by the Earth’s atmosphere turbulence. Therefore, solar adaptive optics aims at these requirements and it has revitalized ground-based solar astronomy at existing telescopes. Meanwhile, multi-conjugate adaptive optics has been proved to overcome the anisoplanatism and obtain the high resolution images with a large field of view in solar observation by compensating for the turbulence with several deformable mirrors conjugated to different heights. In this review, we give some summarization of the development of solar adaptive abroad, and emphatically introduce several adaptive optics systems in China and the progress of large FoV adaptive optics.

For satisfying the boarder application requirement of adaptive optics (AO) and solving the problem of large volume and high cost of conventional deformable mirrors (DM), micro DM based on micro-electro-mechanical system (MEMS) technology is developed and measured. The developed DM has 140 hexagonal parallel plate capacitor electrostatic actuators. The actuators are arranged as a square array and the pitch is 400 μm. A DM prototype is fabricated by MEMS surface micromachining process and packaged by a ceramic pin grid array (CPGA). A miniaturization multi-channel high voltage driver for the DM is developed too. The measurement results show that the prototype has a surface PV value of 411 nm, RMS value of 78 nm, reflectivity of about 80% in 600 nm to 900 nm wavelength, stroke of 1.8 μm, actuator coupling of 15%, working bandwidth of 13 kHz and step response time of 23 μs. Thus the DM has the advantages of small volume, low cost and fast response. Besides the measurement of single element, the whole DM is controlled open loop to fit Zernike aberration and its fitting capability is demonstrated. Above results indicate that the DM prototype can satisfy initially the requirement of AO system.

Novel system identification for large aperture fast-steering mirror (FSM) is presented in this paper. Using the stochastic parallel gradient descent method (SPGD), the new system identification method is able to identify the complex piezoelectric fast-steering mirror (PZT-FSM) model exactly and greatly improve the correction effect. The principle and mathematical model of the PZT-FSM are stated briefly in the paper firstly. Then the use process of the SPGD algorithm in the system identification for the large aperture PZT-FSM is presented. By using the identified model, the validity and feasibility of the proposed approach is confirmed by our close-loop experiments. To expand the usage of the new method, the input jitter spectrum is also identified using the similar method, which enables us to get a higher correction effect for the special frequency region.

The laser guide star facility (LGSF) is an integral component of thirty meter telescope (TMT), and is of critical importance in enabling TMT to achieve the performance required to meet the Science Requirements for high resolution imaging and spectroscopy. The LGSF is responsible for generating the artificial LGS required by narrow field infrared adaptive optics system (NFIRAOS) and by the next generation of the thirty meter telescope (TMT) AO systems. The following sections will discuss the LGSF’s: design overview, LGSF asterisms, wavefront error budget and Laser Launch Telescope design.

The fifty engineered-manufacture adaptive optics systems developed for the Shen Guang III (SGIII) facility, are introduced in this paper. The system technical scheme, together with the key components – the dismountable large aperture deformed mirror and the auto-alignment Shack-Hartmann wavefront sensor, are presented. The characteristic of the wavefront is measured and analyzed. The result of system correction shows that the adaptive optics systems improved the beam quantity of the SGIII facility, meet the requirement that the laser beam energy is higher than 95% in the 10-time diffraction limit zone, and ensured the laser transmission in the main amplification system of the SGIII facility.

As for computational adaptive plenoptic imaging system, the light-field of the target and interference are measured together, and then according to distribution characteristics of the four-dimensional light-field information between the target and the disturbed factors, target and disturbed factors can be effectively separated. This technique can be used to detect and recover the wavefront distortion caused by interference in the large field of view, and adaptively compensate for complicated wavefront aberration by means of computation. Compared with the traditional adaptive optics imaging method, the proposed method has a larger detecting field of view, and can directly analyze and compute wavefront information based on the extended target.

The optical system simulation software Seelight is a system simulation software with independent intellectual property rights which can simulate beam generation, atmospheric transmission and adaptive beam control. The software provides an effective simulation tool for the application fields of optical system. In this article, we introduce the basic structure of Seelight software, the running interface, and the main modules of model libraries. Using the basic models of adaptive optics to build adaptive optics simulation systems, including the PZT deformable mirror module and the Hartmann wavefront sensor module, which improves the beam quality of the far field by correcting the wavefront aberration due to beam propagation through atmosphere. The correction effect of adaptive optics simulation system is verified under the different turbulence intensity, it is clear that correction residual greatly increased with the increasing of turbulence intensity. The Seelight software can be used to simulate various optical systems including adaptive optics system, and the system can be validated and optimized.