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The diffraction grating is a classic and important optical element, and its design usually traverses the whole parameter space to search for an optimal solution, which is time consuming and inefficient. In order to specify the optimization direction of the grating to obtain clearer physical images and to improve the design efficiency, a new blazing model based on the total internal reflection (TIR) is proposed to analyze the diffraction behavior of the grating from a geometry perspective. The optical tunnel along the ridge direction can be used to understand and quantify the blaze of the grating. This TIR blazing model is demonstrated via three types of surface-relief grating with simple formulas, resulting in the solution space decreasing significantly. By utilization of the estimated upper limit of the diffraction efficiency and the range of the depth and slanted angle generated by the TIR blazing model, how the grating delivers the majority of the light energy to a required diffraction order is revealed. Binary and slanted gratings with >0.93 efficiency of T1 order have been obtained with high probability within the calculated parameter range, regardless of the duty cycle and polarization. The reason why a transmission sawtooth grating cannot blaze the most energy to a high order at normal incidence has been clarified, and the method of using the first or second TIR blaze has also been provided. Through this TIR blazing model, the grating design could be simplified, and accommodation to various application requirements could be optimized as well.Optical coatings formed from amorphous oxide thin films have many applications in precision measurements. The Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and Advanced Virgo use coatings of SiO2 (silica) and TiO2Ta2O5 (titania-doped tantala) and post-deposition annealing to 500°C to achieve low thermal noise and low optical absorption. Optical scattering by these coatings is a key limit to the sensitivity of the detectors. This paper describes optical scattering measurements for single-layer, ion-beam-sputtered thin films on fused silica substrates two samples of Ta2O5 and two of TiO2Ta2O5. Using an imaging scatterometer at a fixed scattering angle of 12.8°, in-situ changes in the optical scatter of each sample were assessed during post-deposition annealing to 500°C in vacuum. The scatter of three of the four coated optics was observed to decrease during the annealing process, by 25-30% for tantala and up to 74% for titania-doped tantala, while the scatter from the fourth sample held constant. Angle-resolved scatter measurements performed before and after vacuum annealing suggest some improvement in three of the four samples. These results demonstrate that post-deposition, high-temperature annealing of single-layer tantala and titania-doped tantala thin films in vacuum does not lead to an increase in scatter, and may actually improve their scatter.Standard circularly polarized Airy light-sheets are synthesized by combining two dephased TE and TM wave fields, polarized in the transverse directions of wave propagation, respectively. Somewhat counterintuitively, the present analysis theoretically demonstrates the existence of unconventional circularly polarized Airy light-sheets, where one of the individual dephased wave fields is polarized along the direction of wave propagation. The vector angular spectrum decomposition method in conjunction with the Lorenz gauge condition and Maxwell's equations allow adequate determination of the Cartesian components of the incident radiated electric field components. selleck kinase inhibitor Subsequently, the Cartesian components of the optical time-averaged radiation force and torque can be determined and computed. The example of a subwavelength light-absorptive (lossy) dielectric sphere is considered based upon the dipole approximation method. The results demonstrate the emergence of negative force components, suggesting retrograde motion and spinning reversal depending on the polarization of the Airy light-sheet and its transverse scale and attenuation parameter. The results are important in the design of light-sheet spinner tweezers and applications involving optical switching and particle manipulation and rotation.This work presents a mid-fusion pipeline that can increase the detection performance of a convolutional neural network (RetinaNet) by including polarimetric images even though the network is trained on a large-scale database containing RGB and monochromatic images (Microsoft COCO). Here, the average precision (AP) for each object class quantifies performance. The goal of this work is to evaluate the usefulness of polarimetry for object detection and recognition of road scenes and determine the conditions that will increase AP. Shadows, reflections, albedo, and other object features that reduce RGB image contrast also decrease the AP. This work demonstrates specific cases for which the AP increases using linear Stokes and polarimetric flux images. Images are fused during the neural network evaluation pipeline, which is referred to as mid-fusion. Here, the AP of polarimetric mid-fusion is greater than the RGB AP in 54 out of 80 detection instances. The recall values for cars and buses are similar for RGB and polarimetry, but values increase from 36% to 38% when using polarimetry for detecting people. Videos of linear Stokes images for four different scenes are collected at three different times of the day for two driving directions. Despite this limited dataset and the use of a pretrained network, this work demonstrates selective enhancement of object detection through mid-fusion of polarimetry to neural networks trained on RGB images.A zoom camera can change its focal length and track moving objects with an adjustable resolution. To extract precise geometric information for the tracked objects, a zoom camera requires an accurate calibration method. High-precision camera calibration methods, however, usually require a number of control points that are not guaranteed in some practical situations. Most zoom cameras suffer radial distortion. Athough a traditional method can recover an undistorted image with known intrinsic parameters, it fails to work for a zoom camera with an unknown focal length. Motivated by these problems, we propose a two-point calibration method (TPCM). In this scheme, we first propose an approximate focal-invariant radial distortion (AFRD) model. With the AFRD model, an RGB image can be undistorted with an unknown focal length. After that, the TPCM method is presented to estimate the focal length and rotation matrix with only two control points for one image. Synthetic experiments demonstrate that the AFRD model is efficient.