A new method improving the design of panoramic lens with a long focal length based on ogive and aspheric surface is proposed. In this design, we use a special conjugation between “annular entrance pupil” and aperture stop to correct the chromatic transverse aberrations. Moreover, we use a new imaging relationship to increase the Effective Focal Length (EFL) of the panoramic lens and the CCD utilization. We realize a panoramic lens with a 360° × (45°~85°)field of view (FOV) and a 10.375mm EFL, which is 1.54 times than the conventional imaging relationship.

Fourier ptychographic microscopy (FPM) is a recently proposed computational imaging method that achieves both high resolution (HR) and wide field of view. In the conventional FPM model, the sample is assumed to be a 2D thin layer, and a series of low-resolution images at different illumination angles is used for HR image reconstruction. However, in practice, the sample complex amplitude distribution is usually mixed with some unknown background interferences. These background interferences may result from inhomogeneous media distribution or other defocusing layers, etc. The background interference will significantly degrade FPM reconstruction results, but so far it is not considered in the conventional FPM algorithm. Here, we propose a method that adaptively separates background interferences for each illumination angle. Experimental results show that the proposed method has a faster convergence speed and better reconstruction accuracy than the conventional FPM model.

The cubic Fe3O4 nanoparticles with sharp horns that display the size distribution between 100 and 200 nm are utilized to substitute the magnetic sensitive medium (carbonyl iron powders, CIPs) and abrasives (CeO2/diamond) simultaneously which are widely employed in conventional magnetorheological finishing fluid. The removal rate of this novel fluid is extremely low compared with the value of conventional one even though the spot of the former is much bigger. This surprising phenomenon is generated due to the small size and low saturation magnetization (M s) of Fe3O4 and corresponding weak shear stress under external magnetic field according to material removal rate model of magnetorheological finishing (MRF). Different from conventional D-shaped finishing spot, the low M s also results in a shuttle-like spot because the magnetic controllability is weak and particles in the fringe of spot are loose. The surface texture as well as figure accuracy and PSD1 (power spectrum density) of potassium dihydrogen phosphate (KDP) is greatly improved after MRF, which clearly prove the feasibility of substituting CIP and abrasive with Fe3O4 in our novel MRF design.

Traditional potassium dihydrogen phosphate (KDP) polishing methods, such as magnetorheological finishing (MRF), ion-beam figuring (IBF), and chemical mechanical polishing (CMP), are limited by either hard-to-remove residual particles, unavoidable heating effects, or an applicability restricted to large-sized KDP. In this paper, we present a novel abrasive-free jet polishing (AFJP) mechanism that can be implemented for abrasive-free and no-residue polishing on KDP surfaces. KDP AFJP makes use of a thermodynamically and kinetically stable ionic liquid (IL) microemulsion that contains nanometer range water droplets evenly dispersed in the non-aqueous carrier liquid. The sprayed out nanoscale water droplets can remove material through dissolution. The feasibility of this approach has first been analyzed through several experiments, namely compatibility tests and assessments of removal controllability and uniformity of the IL microemulsion. The material removal mechanisms in contact removal and slipping removal were then studied. KDP AFJP experiments were then conducted to validate the polishing performance. The experimental results show that an IL microemulsion as an abrasive-free jet can indeed improve the quality of a KDP surface, leaving no residue.

In semiconductor manufacturing, defect inspection in non-patterned wafer production lines is essential to ensure high-quality integrated circuits. However, in actual production lines, achieving both high efficiency and high sensitivity at the same time is a significant challenge due to their mutual constraints. To achieve a reasonable trade-off between detection efficiency and sensitivity, this paper integrates the time delay integration (TDI) technology into dark-field microscopy. The TDI image sensor is utilized instead of a photomultiplier tube to realize multi-point simultaneous scanning. Experiments illustrate that the increase in the number of TDI stages and reduction in the column fixed pattern noise effectively improve the signal-to-noise ratio of particle defects without sacrificing the detecting efficiency.

This study presents a novel abrasive-free jet process that can be used to mitigate the lattice misaligned structure induced by mechanical stresses in potassium dihydrogen phosphate (KDP) crystal subsurface. This method makes use of a thermodynamically and kinetically stable ionic liquid microemulsion that contains nanometer range water droplets evenly dispersed in the non-aqueous carrier liquid. The sprayed out nanoscale droplets remove material through microscale dissolution without introducing new residual stress. Grazing incidence X-ray diffraction was used to evaluate the subsurface structure and to validate the mitigating performance. The experimental results show that the novel mitigation method can effectively reduce the thickness of the deformed layer, as well as reduce the surface roughness. This approach ultimately provides a potential path to extend the lifetime of highly valuable and difficult to grow large KDP crystals.