Influence of spherical aberration on the tightly focusing characteristics of vector vortex beams.

For a tightly focusing imaging system, the aberration of the lens will result in a distorted focusing spot and undermine the system performance. In this paper, the expression of the tightly focused light field of Laguerre-Gaussian vector vortex beam (LGVVB) is deduced. Then the intensity distribution, focal shift and spot size that influenced by spherical aberration are calculated in detail.

Co-phase errors sensing method for Golay3 telescope system via a transfer network.

Optical sparse-aperture systems face severe challenges, including detecting and correcting co-phase errors. In this study, a search framework based on fine tuning a pre-trained network is proposed to analyze the co-phase errors of a Golay3 telescope system. Based on this, an error compensation control system is established.

Phase retrieval from single interferogram without carrier using Lissajous ellipse fitting technology.

Phase extraction from single interferogram is of high significance and increasingly interest in optical metrology. In this contribute we propose an advanced Pixel-level Lissajous Ellipse Fitting (APLEF) method to extract the phase from single interferogram without carrier. At each pixel, a Lissajous figure is created by plotting N against D, where N and D are subtractions and additions of intensities of adjacent pixels in a small window.

Effects of iron impurities on the photoelectric response characteristics of silicon.

Since Fe contamination is easily mixed into Si-based photoelectric materials during the fabrication process, the relative changes of energy levels and photoelectric properties of Si material mixed with Fe impurities in different occupancy sites are studied. Based on the first principle and photoelectric response theory, an analysis model of the response characteristics of Si material mixed with Fe impurities is established. The changes of the material's electronic structure are calculated, and the effects of different occupancy sites of Fe impurities on the photoelectric response characteristics of materials are comparatively analyzed.

Application of torque sensitivity in the alignment of a Cassegrain system.

In order to improve the alignment accuracy of a Cassegrain system, to the best of our knowledge, a novel computer-aided alignment method based on torque sensitivity is proposed. Different from the traditional position sensitivity curve guiding scheme, the accurate position of the secondary mirror is not necessary while the torque sensitivity curve is generated. By establishing the relationship between the torque of the secondary mirror setting screw and the Zernike coefficients of the system, a practical quantitative alignment scheme for the Cassegrain system can be realized.

Multi-Scale Mixed Attention Network for CT and MRI Image Fusion.

Recently, the rapid development of the Internet of Things has contributed to the generation of telemedicine. However, online diagnoses by doctors require the analyses of multiple multi-modal medical images, which are inconvenient and inefficient. Multi-modal medical image fusion is proposed to solve this problem.

Illumination characteristics of vortex beams in dark-field microscopic systems.

A Laguerre-Gaussian (LG) vortex beam is employed as an illumination source for a dark-field microscopy imaging system. To discover the influences of beam characteristics on the imaging quality, an analysis model has been established to show the light-field change rule on both object and image planes. The analytic expressions of the light field on the two planes are deduced.

Entropy-Based Image Fusion with Joint Sparse Representation and Rolling Guidance Filter.

Image fusion is a very practical technology that can be applied in many fields, such as medicine, remote sensing and surveillance. An image fusion method using multi-scale decomposition and joint sparse representation is introduced in this paper. First, joint sparse representation is applied to decompose two source images into a common image and two innovation images.

Amplitude randomness of spontaneous emission influence on the coherence properties of a laser.

Based on the randomness of spontaneous emission, the statistical characteristics of phase noise are discussed. A theoretical analysis model, focusing on the amplitude randomness of spontaneous emission, is established to calculate laser phase noise. Then, the coherence of a laser before and after phase-locked control is calculated when an ideal laser and nonideal laser are used as a reference light in an optical phase-locked loop (OPLL).

Thermal accumulation effect of a three-junction GaAs cell with multipulse laser irradiation.

A theoretical model on accumulation of temperature and stress in a three-junction GaAs solar cell is proposed to analyze its damage characteristics while irradiated by a multipulse laser. The distribution and accumulation effect of temperature and stress with different pulse widths are calculated. Specifically, the influences of pulse energy and duty ratio on the accumulation effect are discussed.

A novel design method for continuous-phase plate.

A continuous-phase plate (CPP) is a key element for beam smoothing in a high-power laser system. For the beam-smoothing effect, the surface shape of a CPP is one of the most important facts. In this paper, the change law of the transmission direction of light rays has been analyzed according to the geometrical optical principle.

Continuous phase plate for laser beam smoothing.

We discuss the beam smoothing principle of a continuous phase plate (CPP) while the input light is varying. The analysis model of the process in which the laser beam with random phase noise propagates through a CPP has been established. With this model the beam smoothing mechanism of the CPP for the laser beam with a different phase aberrations can be described.

Precision analyses of a stitching interferometer testing system.

The most basic task in subaperture stitching test work is to confirm the precision of the system. We propose a method with which to calculate the system's precision. Statistical theory, especially regressive analysis, is employed.