Kampertran2244

In this paper, we present theoretical foundations of first-order design of an imaging refractometer. This refractometer may be used to measure the refractive index of liquids over a wide range. Refractive index reconstruction techniques are presented, and analytical reconstruction expressions are derived. The validity of the derived formulas is tested and is in good agreement with Gaussian reduction results. Design examples are provided and discussed. Limitations of the proposed measuring techniques are discussed, and theoretical models as well as numerical examples for the accuracy are presented.Art conservators have adopted optical technologies to improve conservation efforts; laser triangulation, stereophotogrammetry, structured light, laser scanners, and time of flight sensors have been deployed to capture the 3D information of sculptures and architectures. Optical coherence tomography (OCT) has introduced new imaging methods to study the surface features and subsurface structures of delicate cultural heritage objects. However, the field of view of OCT severely limits the scanning area. We present a hybrid scanning platform combined with an effective algorithm for real-time sampling and artifact removal to achieve macroscopic OCT (macro-OCT) imaging and spectral 3D reconstruction of impressionist style oil paintings.A pair of axicons with an adjustable separation between them is used to generate a variable diameter ring beam with high efficiency. This beam illuminates a lens to produce quasi-diffraction-free beams with a tunable spot size and depth of field. We studied the generated beam characteristics while changing either the ring diameter or its thickness. Such a scheme has applications in adjustable imaging, including nondiffracting beam microscopy, material processing with an irradiance above a certain threshold value, and particle trapping/manipulation.We present a modified model for residual intensity modulation (RIM) observed in lithium niobate phase modulators, which is suitable for both narrow linewidth and wide linewidth lasers. This model is based on two key points leading to RIM one is the optical propagation loss, which is proportional to the applied voltage, and the other is the interference between an injected wave and its reflection from the lithium niobate substrate. In order to verify the model, the RIM is measured accurately with different linewidths of input lasers respectively. The experimental results are in good agreement with the theoretical model as the values of fitting determination coefficient R-square are all above 0.995. selleck compound The results have revealed that the chief reasons causing RIM are different. When using a narrow linewidth laser, the interference is the dominant reason leading to RIM as the ratio of the reflection-related coefficient including linewidth effects to optical loss reaches 34.33. However, the optical loss is the dominant reason leading to RIM with the ratio mentioned above reaching 0.31 when using a wide linewidth laser.This publisher's note corrects information in the author affiliations in Appl. Opt.58, 7205 (2019).APOPAI0003-693510.1364/AO.58.007205.This study presents a new (to the best of our knowledge) error separation method with a single displacement probe, named as single probe shear scanning (SPSS) method, for the on-machine optical profile measurement to overcome the problems of the existing multiprobe method like the large deviation of probe spacing and the probes' performance difference. The confocal sensor with superior dynamic range, high lateral resolution, and large measurement angle to surface is applied in this study to fulfill the measurement of the optical aspheric surface. The single probe measurement system, in which the probe fixed on a flexure hinge is driven straight within a millimeter-level travel range, is established to realize the function of the multiprobe. For the established system, a new exact profile reconstruction algorithm is built to eliminate the influences of straightness errors of the scanning stage and the systemic errors of shear stage, and to reduce the effect of the sensor drift. The reconstruction algorithms by difference measurement with two shears are studied to build the bidirectional segment stitching reconstruction method, which reduces the error accumulation and improves the reconstruction accuracy under the condition of measuring errors. A profile reconstruction method with three shears measurement is proposed to make a further improvement on the reconstruction accuracy. The proposed reconstruction method with three shears measurement is successfully employed for the on-machine measurement of an aspheric surface profile, and the evaluation results agree well with those from the Taylor profiler.Since the pupil function is defined as a time-invariant system, the traditional partially coherent imaging model is time-consuming to calculate the effect of spatially varying wavefront aberrations on the scanning image. A fast reconstruction method of the aberrated scanning aerial image is presented for the scanning projection lithographic tool. In the proposed method, the principal components (PCs) are used to decompose and reconstruct the aberrated aerial image. Due to the exact quadratic relationship between the PC coefficients and the Zernike coefficients, the integration of the PCs in the intensity domain can be transformed into the integration of quadratic Zernike vectors when reconstructing the scanning aerial image. An integral transfer function is introduced to describe this process. This method can not only reconstruct the aberrated scanning image quickly but can also obtain the explicit relationship between the Zernike coefficients and the aberrated scanning aerial image.Optical vortex beams carry orbital angular momentum and thus exert torque on illuminated objects. A dielectric microtool-a microbarbell-is used in two-laser optical tweezers to measure the torque of a focused optical vortex. The tool was either freely rotating due to the applied torque or set into oscillations by the counteracting force. Four different trapping configurations provided different ways of sensing the torque and gave consistent results. The value of torque was determined by confronting the experimental results with numerical and analytical models.