The results demonstrate that the compensative CROF has no dependence on whether the reflecting-faces of the CCR are coated or not and is inversely proportional to the absolute value of DAEs. The received optical power is promptly enhanced by utilizing the compensative CROF. Therefore, it is more feasible to improve the received optical power of the ground-based optical instrument by manipulating the CROF of the CCR rather than the DAEs.Depth estimation is crucial in many light field applications. However, the accuracy of light field depth estimation is prone to be affected by occlusions. In this paper, a method of side window angular coherence is proposed to handle different types of occlusions, and the ability of the proposed method to resist occlusions is theoretically analyzed. The angular patch is divided into several discrete side window subsets. These subsets are a pure occluder-type subset, a pure object point-type subset, and a hybrid-type subset. The photo-consistency of the pure object point-type subset can reflect the true depth. Meanwhile, the occlusion edges can be detected to identify occluded points and nonoccluded points so the robustness of the algorithm can be further enhanced by processing the two types of points. Moreover, fast guided filtering is applied to cost volume for improving the accuracy of depth estimation. Experimental results demonstrate that our method outperforms the state-of-the-art depth estimation methods on both synthetic and real scenes, especially near occlusion boundaries.The convex reflective diffraction grating is an essential optical component in Offner systems, which has been widely used in imaging spectrometers. We propose a new design and optimization method for the convex blazed grating in the Offner imaging spectrometer. The method integrates the macro- and microdesign of the optical system, and it can be used to design and optimize the convex blazed grating with high diffraction efficiency. Traditional geometric optics theory and image quality evaluation methods are used to design the macro-optical structure parameters of the Offner system. And then the incident ray information, such as the incident angle and the polarization states are calculated by using the three-dimensional polarization ray-tracing method. To improve the diffraction efficiency, we combine rigorous coupled wave analysis and a particle swarm optimization algorithm to optimize the microstructure parameters of the convex-blazed grating.  https://www.selleckchem.com/products/nvp-bgt226.html  Further, a convex-blazed grating in a mid-wave infrared Offner imaging spectrometer is designed as an example to illustrate our design method in detail. The design results indicate that the Offner imaging spectrometer has good imaging quality, and the average diffraction efficiency of the -1st diffraction order of the convex-blazed grating in the spectral coverage 3-5 µm is 82.24%. Compared to the traditional design method, the lowest spectral diffraction efficiency is improved from 59.88% to 69.24%, the highest spectral diffraction efficiency is improved from 90.45% to 91.84%, and the standard deviation is reduced from 7.82 to 6.62.This erratum serves to correct an inadvertent error made during the presentation of results involving the mislabeling of the orientation of linear polarization perpendicular as parallel and vice versa in Appl. Opt.59, 8314 (2020)APOPAI0003-693510.1364/AO.396709.We present the general formula to design a mirror such that it reflects the light of a given arbitrary wavefront as a plane wave for two and three dimensions. The formula is fully analytical and close-form. We test the mentioned equations with ray tracing techniques. The results were as expected. We do not use any paraxial concepts or numerical approximations during its derivation.The development of random lasers (RLs) is attracting considerable interest. Here, we investigate how the nonlinear optical behaviors of scattering particles can affect the emission of RLs. In this regard, molybdenum oxide is synthesized by the electrodeposition method, and its nonlinear optical properties are measured using the Z-scan technique. Then, to study the nonlinear effects on RL emission, we insert molybdenum oxide in a conventional RL. It was observed that the emitted intensity enhanced for samples with a positive sign of nonlinear refractive index, while intensity degraded for samples with a negative refractive index. Our results show that both the sign and magnitude of the nonlinear refractive index can modify the intensity of RL emission at pump energies enough above the threshold.An optical fiber having the properties of photonic crystal and offering new diversity and features beyond a conventional optical fiber is the photonic crystal fiber (PCF). In this paper, a simplified version of a highly sensitive plasmonic sensor, called a "slotted PCF based plasmonic biosensor," is studied numerically with asymmetric air holes using the finite element method. From numerical records through the interrogation method, the maximum obtained wavelength sensitivity and amplitude sensitivity are 22000 nm/RIU and 1782.56RIU-1, respectively, with a maximum wavelength resolution of 4.54×10-6RIU-1 RIU for the y-polarized mode. Finally, optimization of the sensor performance is scrutinized, and the effect of different parameters is studied with proper resonance wavelength curve fitting. The design structure of the fiber is simple, symmetrical, easy to fabricate, and cost effective and has higher sensitivity than other PCF based sensors. Having a symmetric orientation of air holes, classic geometric structure, and higher sensitivity, it has the capability to be used in sensing applications, refractive index detection, and identification of biochemicals, biomolecules, and other analytes.Fresnel lens arrays are widely employed in concentrator photovoltaics, photonic devices, and integral imaging systems. In this study, a rapid non-isothermal imprinting process for Fresnel lens arrays was proposed. In this process, a heated mold with microstructures was momentarily pressed onto a thermoplastic polymer surface that was initially kept at room temperature. The microstructures of the mold can be copied completely to the polymer substrate by imprinting consecutively until a continuous surface Fresnel lens array is obtained. Different from more traditional molding processes, the substrate does not need to be heated and cooled repeatedly in the replicating process. In addition, the imprinting process is carried out at room temperature, which can greatly reduce the thermal cycle time and energy consumption. Generally speaking, the material flow and stress distribution of the substrate need to be monitored so that the microlenses with a high precision surface finish can be produced in the non-isothermal imprinting process.