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Liquid crystal (LC) adaptive optics systems (AOS) can potentially be used in ground-based large aperture telescopes, because of their high spatial resolution, low cost and compact size. However, their disadvantages, such as low energy efficiency and slow response speed, still hinder their application. In this paper, we demonstrate solutions to these problems. With newly synthesized fast nematic LC material and using an overdriving technique, the response time of a LC wavefront corrector was reduced to 0.75 ms. Under an open-loop control scheme, a novel optical system was designed to improve the energy efficiency of LC AOS. With those problems resolved, a LC AOS was built for a 1.23-m telescope. This system has a disturbance rejection bandwidth of 80 Hz, and could fully use the energy of 400–900 nm wavebands. Observation results showed that the diffraction limit resolution imaging of the telescope could be obtained after correction, which indicates that the LC AOS is ready to be used in ground-based telescopes for visible waveband imaging.

A set of liquid crystal adaptive optics system for visible light is installed for 2-meter telescope in Changchun, China. To get higher resolution images after adaptive optics, phase diversity (PD) is applied. Two liquid crystal spatial light modulators were used for two polarized states of light, and they were also used for two channel correction of focused image and diversity image. Observations about star HD 29139 were performed on March 23, 2018. The results of the star with the PD show that the full width half maximum was decreased from about 10 pixels to 4 pixels, corresponding to angular resolution improved from 0.5” to 0.2”. The peak intensity was improved by 66.7% after the PD. The root mean square of the wavefront estimated using the PD agrees with the Strehl ratio of observed image after adaptive optics. The observed results indicate that the PD technique can significantly improve the image resolution after liquid crystal adaptive optics.

Two-photon light-sheet microscopy (TP-LSM) system performance is greatly degraded by specimen-induced aberrations in illumination path, which limit the field of view, axial resolution and excitation efficiency of the system. Adaptive optics (AO) is an effective method for attenuating these effects. For the design and evaluation of an AO system, a comprehensive analysis of the effects of aberrations is needed. In this paper, a TP-LSM system is simulated, and new indexes based on integral intensity are introduced for the evaluation of an aberrated light-sheet. Then, the influences of each Zernike mode and random aberrations on the illumination path of the TP-LSM system are investigated with a numerical simulation method. Results show that high-order aberrations have little effect on the axial resolution and excitation efficiency of the system and only low-order components require correction. The random aberrations varied in strength with the depth of the specimens, so the number of corrected Zernike modes is variable. A general formula is generated for the estimation of the number of modes that should be detected and corrected under different aberrations and different numerical aperture of the objective. The results can provide important guidance in the design and evaluation of AO units for TP-LSM systems.

This article analyzes the current problems in the teaching of computer majors in the era of big data and proposes that teachers should change their teaching methods. Teachers should implement personalized teaching reforms with the help of student learning resource data and combine teaching with big data massive teaching resources. To improve teaching methods, guide students to independently formulate learning programs based on their own knowledge of knowledge, promote students’ autonomous learning ability, and achieve the goal of improving teaching quality. Colleagues suggested that teaching in the era of big data needs to strengthen the construction of resource platforms as a strong support.