Based on the interferometric particle imaging (IPI) technology, we present a method for comparison of aspect ratios of ellipsoidal particles. By simulating the interference in-focus and out-of-focus images of transparent ellipsoidal particles with different aspect ratios, we find that, under the same orientation angle, the larger the particle aspect ratio is, the higher the spatial frequency of the out-of-focus image. The IPI system is established to experimentally acquire the out-of-focus images of the transparent ellipsoidal particles. Because the experimental results agree with the simulation, we propose a method to compare the aspect ratios of ellipsoidal particles using out-of-focus images. The method features potential applications in particle measurements.An upper bound is derived for a figure of merit that quantifies the error in reconstructed pixel or voxel values induced by the presence of null functions for any list-mode system. It is shown that this upper bound decreases as the region in attribute space occupied by the allowable attribute vectors expands. This upper bound allows quantification of the reduction in this error when this type of expansion is implemented. Of course, reconstruction error is also caused by system noise in the data, which has to be treated statistically, but we will not be addressing that problem here. This method is not restricted to pixelized or voxelized reconstructions and can in fact be applied to any region of interest. The upper bound for pixelized reconstructions is demonstrated on a list-mode 2D Radon transform example. The expansion in the attribute space is implemented by doubling the number of views. The results show how the pixel size and number of views both affect the upper bound on reconstruction error from null functions. This reconstruction error can be averaged over all pixels to give a single number or can be plotted as a function on the pixel grid. Both approaches are demonstrated for the example system. In conclusion, this method can be applied to any list-mode system for which the system operator is known and could be used in the design of the systems and reconstruction algorithms.The present paper describes a novel implementation of the continuous phase shifting method (PSM), named heterodyne holography, in a scanning probe microscope configuration, able to retrieve the complex scattered field in on-axis configuration. This can be achieved by acquiring a continuous sequence of holograms at different wavelengths in just a single scan through the combination of scanning interference microscopy and a low-coherent signal acquired in the frequency domain. This method exploits the main advantages of the phase shifting technique and avoids some limits relative to off-axis holography in providing quantitative phase imaging.At present, the application of machine vision methods for roughness measurement in production sites is limited by its adaptability to illumination variations during the measurement. In this study, a machine vision method for roughness measurement with robustness to illumination is proposed so as to explore the functions of its color image indices in improving the mathematical expression of the vector of three primary colors. Besides, virtual images of different-roughness surfaces were analyzed, the effects of the samples' surface texture orientations on measurement indices were discussed, and the singular value ratio was derived as an index for evaluating roughness. The experimental results showed that the samples' index values remained unchanged when the illumination was increased for both vertical and horizontal surface textures, indicating that the proposed method has strong robustness to illumination. In addition, the experimental results were verified by a support vector machine (SVM)-based method using 10 different-roughness test samples, with the verification range of 0.127-2.245 µm. It was found that the measurement accuracy reached 90%, suggesting that the proposed method is reasonable and feasible, and shows certain potential to be applied in engineering.Many LED lighting applications involve the design of multiple optical surfaces. A prime example is a single lens with two refractive surfaces. IOX1 In this paper, we consider an LED light source approximated as a point and a far-field target intensity. Using Hamilton's characteristic functions, the design problem is converted into two generalized Monge-Ampère equations by deriving a generating function for each optical surface. The generating function is a generalization of the cost function in optimal transport theory. The generalized Monge-Ampère equations are solved using an iterative least-squares algorithm. To compute the first optical surface, we choose an intermediate far-field target intensity. By choosing different intermediate target intensities based on the source and target intensity, we develop a "knob" to distribute the refractive power over both surfaces of the lens. We apply the algorithm on two example problems and show it is capable of producing complicated target distributions.A theoretical analysis of properties of an objective composed of three thin lenses is described in this paper. The formulas for the calculation of parameters of the three-lens objective are derived and the procedure for calculation of the shape of individual lenses of the objective is described using the third-order aberration theory. The application of the described analysis is presented in an example of the design of the three-lens objective.A hybrid optoelectronic bistability is realized with the assistance of an ultrahigh-order mode (UHM) excited in a symmetrical metal-cladding waveguide (SMCW). PMN-PT ceramics is selected as the guiding layer, which possesses the voltage modulated refractive index and thickness by means of an electro-optical effect and converse-piezoelectric effect. An amplified voltage signal translated from the intensity of reflected light is exerted on the guiding layer, whose parameter variations can alter the resonance condition of the UHM and finally lead to a dramatic change in the intensity of the reflected light. Since the full width at half-maximum of the UHM is extremely narrow, a hysteresis behavior with a milliwatt threshold between the incident light and the reflected light can be achieved when a positive feedback is established. Our bistability configuration is simple and not limited to TM polarization.