Aberration Of Light Research Articles

Topography reconstruction of high aspect ratio silicon trench array via near-infrared coherence scanning interferometry

Topography measurement of high aspect ratio trench array using coherence scanning interferometry presents significant challenges because the numerical aperture of detection light is constrained by the trenches. Altering the detection light to penetrate the sample like near-infrared light for silicon could overcome this obstacle, but the trench array spreads the detection light. This study introduces a coherence scanning interferometry model based on three-dimensional point spread function and assuming sample is transparent to detection light, which is realized by integrating rigorous numerical electromagnetic field solution to quantify the modulation aberrations of detection light by transparent trench arrays, and theoretical angular spectrum diffraction utilized for far-field interference imaging. This model facilitates a thorough analysis of the aberrations introduced by trench arrays, encompassing comparisons between trench arrays and a single trench, as well as between the symmetric region of the array and the asymmetric region at the edge. Additionally, an investigation into the impact of unified compensation for low-order aberrations on the topography reconstruction is presented, and we find the sample-induced aberration compensation method utilizing a deformable mirror that we previously proposed for a single trench is still effective confronting trench array. Experimental measurements are performed on silicon trench arrays with the aspect ratio of up to 20:1 and the period of approximately 10 µm to validate the effectiveness of our model and measurement methods, thus providing valuable insights for enhancing high aspect ratio manufacturing.

SPECIAL THEORY OF RELATIVITY IS ALSO FAILED TO EXPLAIN NULL RESULT OF MICHELSON AND MORLEY EXPERIMENT

Michelson and Morley conducted an experiment in the year 1887 to measure the speed of earth in luminiferous aether. In this experiment Michelson’s interferometer was used in which two waves are superimposed to generate interference fringes. Keeping in view known velocity of earth around the sun a fringe shift of 0.44 fringe was expected on the rotation of interferometer at an angle of 900, but surprisingly no fringe shift was observed. The experiment was conducted so many times and at so many places but always null results were obtained. The null result of MMX could not be explained by classical mechanics. A number of explanations for null results were submitted but no one was found to be correct. George Fitzerald and Hendrick Lorentz proposed length contraction hypothesis in the direction of motion of earth, but it was also rejected being an adhoc hypothesis. Albert Einstein submitted his famous theory “The special theory of relativity” in the year 1905. The second postulate of the STR states that speed of light is constant in all directions of inertial frames of reference irrespective of motion of source of light or the observer and states that no luminiferous aether exist as a medium, light waves do not require any medium to propagate. As light travels with constant velocity in both the arms of interferometer irrespective of motion of interferometer and there involves no time difference between the two rays hence null results of MMX were explained by special theory of relativity. Michelson and Morley experiment is based on the wave nature of light. In such experiments wavefront of light plays very important role but behaviour of wavefront of light was not taken into consideration while deriving the time taken by the light rays in the arms of interferometer due to motion of earth resulting into wrong derivation of time. The present article describes the principle and realization of role of wavefront of light in MMX. The time taken by light rays in the arms of the interferometer due to motion of earth depends upon the behaviour of wavefront of light. It has been established by results of Fizeau experiment and steller aberration of light that speed of light is not effected by velocity of moving medium. The derivation of time has been worked out keeping in view constancy of speed of light, wavefront of light and laws of reflection of light according to Huygen’s principle. Contrary to earlier beliefs the Lorentz length contraction hypothesis is not able to explain the null results of MMX. In the light of new facts it is established that there is no difference between theorectical results derived by classical mechanics and special theory of relativity. Special theory of relativity is also failed to explain the null result of MMX. The null result of Michelson and Morley experiment has again become a perplexing question for physicists.

Speed and Aberration of Light and Redshift

Speed and Aberration of Light and Redshift

Image based automatic wind velocity profiler for adaptive optics

Abstract Adaptive optics (AO) systems correct optical phase aberrations of the incoming light generated by the atmosphere. To do so simultaneous estimators of the atmospheric turbulence parameters are required. For the family of wide-field AO systems (WFAO), this information must be stratified in altitude. Among these vectorized estimations, wind profiling in altitude is needed for the reduction of temporal errors in AO loops or for the estimation of turbulence coherence time. This paper proposes a turbulence wind profiler called image processing based peak tracking algorithm (IPTA). IPTA is an image-processing based approach that automatically and reliably estimates wind velocity for several turbulent layers along the line of sight. The estimation of each wind layer is achieved by tracking peaks produced in cross-correlation maps from pairs of wavefront sensors (WFSs) slopes using the technique known as SLODAR (slope detection and ranging). Results for simulated and on-sky WFS datasets demonstrate that IPTA outperforms one of the state of the art wind profiler methods (the profiler covariance parametrization of wind velocity (CAW)) in terms of accuracy and speed. Results also show that, in terms of execution time, our method scales better when the number of WFS lenslets is increased. Being an open source and reliable tool, we believe IPTA can be a useful wind profiler for the adaptive optics community.

Stimulated Raman scattering microscopy with phase-controlled light focusing and aberration correction for rapid and label-free, volumetric deep tissue imaging

Stimulated Raman scattering microscopy with phase-controlled light focusing and aberration correction for rapid and label-free, volumetric deep tissue imaging

A test to the constancy of the velocity of light with our solar system

This article is a detailed proposal of an astronomical test to be carried out within our solar system to try to detect the eventual addition of the speed of a celestial body to that of its emitted light -that reflected of the Sun in this case. This eventuality could be determined by observing the consequent variation in its apparent position that could produce the variation of the angle of aberration, a consequence, in turn, of the variation of the velocity of its emitted light. This area is chosen, despite having here celestial bodies with lower speeds than those of the stars, and their consequent lower sensitivity in the observations, to avoid the inconvenience of the enormous interstellar distances, which could disqualify the results of the test due to the possible intervention of the phenomenon of extinction of the light wave in that distances, as we will see in the Introduction of this article. To carry out the above, we need to have celestial bodies of different radial speeds with respect to our Earth, and in this area, we find them in the satellites of the other planets in the extreme positions of their orbits; and the observation of the possible different aberrations, in the variation of the apparent separations of the satellites from their planets in those positions. The proposal also includes the observation of the transit of a satellite across the front of its planet to detect the possible appearance of this phenomenon also in this different circumstance. It will also be possible to determine if it is the relative speed between the light source and the observer the one that effectively intervenes in this phenomenon of light aberration—planetary in this case—or if it is only that of the observer—that of our Earth—that produces it, as several authors maintain. To adequately illustrate the proposed test, and the order of magnitude of the intervening parameters, a specific example is developed with Jupiter and two of its satellites: IO and METIS.

Light Clock Behavior Explained via Relativistic Aberration of Light

In the following paper we explain the functionality of the light clock via the relativistic aberration of light. A second explanation, through relativistic speed composition will be provided. The behavior of the light clock is an important tool in explaining time dilation. This article is intended for educators teaching special relativity as well as for students.

Measuring visual acuity and spherical refraction with smartphone screens emitting blue light

IntroductionA periodical self-monitoring of spherical refraction using smartphones may potentially allow a quicker intervention by eye care professionals to reduce myopia progression. Unfortunately, at low levels of myopia, the far point (FP) can be located far away from the eye which can make interactions with the device difficult. To partially remedy this issue, a novel method is proposed and tested wherein the longitudinal chromatic aberration (LCA) of blue light is leveraged to optically bring the FP closer to the eye. MethodsFirstly, LCA was obtained by measuring spherical refraction subjectively using blue pixels in stimuli shown on organic light-emitting diode (OLED) screens and also grey stimuli with matching luminance. Secondly, the visual acuity (VA) measured with a smartphone located at 1.0 m and 1.5 m and displaying blue optotypes was compared with that obtained clinically standard measurements. Finally, the spherical over refraction obtained in blue light with a smartphone was compared with clinical over-refraction with black and white (B&W) optotypes placed at 6 m. ResultsMean LCA of blue OLED smartphone screens was −0.67 ± 0.11 D. No significant differences (p > 0.05) were found between the VA measured with blue optotypes on a smartphone screen and an eye chart. Mean difference between spherical over-refraction measured subjectively by experienced subjects with smartphones and the one obtained clinically was 0.08 ± 0.34 D. ConclusionsSmartphones using blue light can be used as a tool to detect changes in visual acuity and spherical refraction and facilitate monitoring of myopia progression.

Calibration of the intrinsic parameters of the digital camera of a star tracker based on ground-based observations of stars, taking atmospheric refraction and aberration of light into account

Calibration of the intrinsic parameters of the digital camera of a star tracker based on ground-based observations of stars, taking atmospheric refraction and aberration of light into account

Calibration of intrinsic parameters of a star tracker’s digital camera based on ground-based stars observations, taking into account atmospheric refraction and light aberration

The mathematical model of a digital image contains a set of parameters called camera's intrinsic elements. The numerical values of the elements are unique and must be determined through the individual calibration. The paper considers the problem of fi ve intrinsic elements calibration: the focal length of the lens, two coordinates of the principial point of the image, and two second-order radial distortion coeffi cients. The stars observed by the calibrated camera from the Earth's surface are used as a calibration test pattern. The stellar coordinates are cataloged with very high accuracy, which makes it possible to get rid of complex calibration equipment and reduce the calibration problem to a particular problem of digital image processing. The positions of stars observed from the Earth's surface are distorted by a velocity aberration and atmospheric refraction. These effects are taken into account by introducing distortions into the direction vectors of stars taken from the star catalog. Two approaches to solving the calibration problem are considered, which take into account the unknown orientation of the calibrated camera relative to the Earth in different ways. It has been experimentally shown that both approaches lead to the same results. The discrepancy in calibration measurements after calibration decreases by a factor of 32, to a value on the order of the irremovable angular error in determining the apparent position of a star in a turbulent atmosphere. The results of individual calibration of the camera's intrinsic elements are used in the fi rmware of the star tracker to correct the systematic errors in attitude measurements.

The motion of massless “object” and the physical essence and motion law of light

In this paper, the vacuum absolute static reference system is established by analyzing the motion law of massless “object.” Through the understanding of the physical nature of light, this paper reveals three basic laws of motion of light: First, light always moves in a uniform straight line, independent of the motion of the light source. Second, the speed of light propagation in vacuum is constant relative to the absolute reference system of vacuum. Third, the speed of light propagation in the medium remains constant relative to the inertial frame of the medium. Based on this, we have successfully explained the phenomenon of Michelson‐Morley experiment, Fizeau experiment, and light aberration phenomenon that have long troubled the academic community. Finally, we prove that the two basic assumptions on which special relativity is based are wrong, so the Lorentz transformation and its series of inferences, as the core content of special relativity, are not tenable.

QED-Based Derivation of the General Forms of the Relativistic Doppler Effect and of the Relativistic Aberration

The current paper derives the most general form of the relativistic Doppler effect and of the relativistic aberration starting from base principles available in classical electrodynamics and from the Lorentz transforms of the energy-momentum. Unlike any other material before us, we derive the relativistic Doppler formula for the case of both source and receiver moving in arbitrary directions with respect to an inertial reference frame. Thus, our derivation employs three different reference frames: one commoving with the source, the second one commoving with the receiver and the third one, commoving with the observer. The general formula, once derived, allows us to tease out all the specific cases, like the one from the perspective of the receiver, the one expressing the transverse Doppler effect, and the general formula for the Doppler rotor effect. We close with the derivation of the general formula for relativistic light aberration.

Interferometry by a transparent wedge

In this article we show that a single transparent wedge or a plate with a wedge part can be used as a very simple and useful interferometer with numerous applications. This interferometer permits to modulate phase distribution on interference fringes to evaluate quantitatively the parallelism of a light beam and aberration of a wavefront, to specify the spectral line shape in a wide range, to measure the light wavelength and refractive indices of solids and liquids. In addition, it provides suitable beams for holographic study of phase objects and fabrication of diffraction gratings.

Ретрорефлекторные сферические системы стеклянных спутников "Блиц"

Spatial and energy characteristics of the BLITS glass geodesic passive satellites with radial symmetry for high-precision laser ranging in the interests of GLONASS were analyzed. Principles of calculating the retroreflector spherical system of satellites being a set of concentric layers with different refractive index and thickness were considered. In this case and in accordance with specifics of space application of the retroreflector spherical system of satellites, it is necessary to ensure the maximum reflected power in the receiver direction taking into account phenomenon of the light high-speed aberration. It is shown that on the basis of simulating in the Zemax program, it becomes possible to select optimal parameters of the optical elements, i.e., curvature radii and refractive indices taking into account the production technological capabilities, which are forming the required curvature of the reflected light wave surface. Based on the aberration calculation, diffraction patterns of the reflected coherent laser radiation in the far zone were analyzed, and design options for a retroreflector spherical system of satellites with increased maxima of the first or second orders were selected. A formula is provided for estimating spatial energy characteristics of the BLITS satellites including the equivalent scattering surface. The concept of the outflow beam efficient diameter is introduced, within which the reflected light forms a diffraction pattern in the far zone

The Truth on Gravity and Terrestrial Global Warming. Part 1: The Quantum Gravity Field

Although during the last century both experimental and computational technology progress has accumulated solid factual information on the deeper knowledge of our actual world, the previous approaches derived in most cases from the unfinished Einstein’s theory of gravity using untrue models for the torsion tensor, have failed to explain the gravitational and precessional aspects, causally connected with the morphogenesis of matter engendered by the bending of light. The torsion/ twisted process during the refrigeration of hot matter (lava) is essential for the understanding of gravitation phenomena as embodied/ gravitized mass occurring at the polarization of light. The Lorentz polarized field concept, (4π/3)P(Ker), associated with a quantum partition kernel, Ker = (1/2, 2/3, 3/4), of the light polarization for radiant energy, mass and gravity, respectively, is generalized for the regenerative matter, including the polarization of time as absolute/orbital time and relative/ precessional time (or the half-life of a regenerative substance). The laws of the Sun like regenerative material systems are given and also the explanations of the quantum origin of gravity along with certain aberration of light in its field are considered.

Object-independent tilt detection for optical sparse aperture system with large-scale piston error via deep convolution neural network

The optical sparse aperture technique can improve the imaging resolution significantly under the ideal co-phase condition. However, the position deviation between different sub-apertures leads to notorious co-phase errors, seriously impacting the image quality. While the position deviation arises in practical applications, it is difficult to detect the errors in real-time for traditional iterative algorithms because of their narrow detection range and long-time iteration process. The deep neural network has shown its potential in optical information process, and it has some attempts in the detection of piston error. However, all existing deep learning-based methods just focus on the detection of piston error with the weak or corrected tilt error, which is not in line with reality. Here we implement the deep convolutional neural network to detect tilt error with large-scale piston error, and compare the detection performance of two kinds of network, one takes the point spread function as input while the other takes the phase diversity features as the input. The detection ability and generalization capability of network are verified under single wavelength, broadband light and turbulence aberration in simulation. The object-independent of tilt error detection ability is offered because the phase diversity features and point spread function are all unrelated to the object. In addition, the cyclic correction strategy is carried out to improve the generalization performance facing the larger errors. As a result, the deep learning-based method can detect the tilt error accurately with fast calculation, and the trained network is hopeful for the real-time correction with cyclic correction strategy.

Современные возможности оптико-реконструктивной хирургии у пациентов после удаления опухоли иридоцилиарной зоны

Choroid tumors constitute 2/3 of all intraocular tumors, out of which 23% are tumors of the iris and the ciliary body, and the rest are tumors of the choroid. After removing the tumor of the iridociliary zone (ICZ) it is necessary to perform optical reconstructive surgery to reduce light aberrations and increase visual functions. Purpose. To identify key features of the complex rehabilitation of patients after removal of the ICZ tumor. Material and methods. The clinical and functional results of the complex rehabilitation of 12 patients (12 eyes) aged from 35 to 84 years (average 66 years) were studied at least 1 year after removal of the ICZ tumor. The area of the iris defect before the reconstructive surgery ranged from 15% to 55%. Preoperative uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were 0.26 ± 0.19 (from 0.01 to 0.6) and 0.46 ± 0.22 (from 0.1 to 0.8) respectively. All patients were underwent phacoemulsification of cataract and implantation of the iris-lens diaphragm. Results. After the reconstructive surgery, UCVA and BCVA increased:0.5 ± 0.17 (from 0.2 to 0.7) and 0.61 ± 0.27 (from 0.3 to 0.9) respectively. Undesirable optical effects were decreased, and patients were satisfied with the cosmetic result. Conclusion. The presented algorithm of optical reconstructive surgery after removal of the ICZ tumor creates necessary conditions for increasing postoperative functional results and improving the quality of life of these patients. Key words: tumor of the iridociliary zone, iris-lens diaphragm, optical reconstructive surgery, phacoemulsification of cataract.

A phase model using the Huber norm for estimating point spread function under frozen flow hypothesis

In astronomical observation and space exploration, the light of an object in the outer space is inevitably distorted by the atmospheric turbulence around the Earth before it reaches the ground-based telescope aperture. The target object so observed is degraded by unknown point spread functions (PSFs). Estimating the PSFs is thus crucial for ground-based astronomy. In order to know the PSFs, we first need to estimate the phase, i.e., the wavefront aberration of incoming light at telescope aperture. In this paper, under the frozen flow hypothesis, we propose a new model for estimating the phase in the case of single- and multi-layered atmospheric turbulence. The new model, which deploys the Huber norm as the regularizer, can be cast as a saddle-point problem and solved efficiently by existing well-developed optimization algorithms. We test a spatially-varying image deblurring problem by using the estimated PSFs, which demonstrates the compelling numerical performance of the new phase model.

Self-calibration dense bundle adjustment of multi-view Worldview-3 basic images

Very high-resolution satellite images (VHRSIs) with improved spatial resolution provide unprecedented opportunities to explore the geometric and semantic information of the world. Accordingly, to compensate for the bias of exterior orientation parameters, bundle adjustment of VHRSIs is required. Owing to the sparse points, the bundle adjustment of a few VHRSIs omits high-frequency errors and attitude jitters; therefore, the rational function model (RFM) can achieve an accuracy comparable to that of a rigorous sensor model (RSM), despite the significant difference between the RSM and RFM. In this study, we provide insight into the role of RSM in modeling attitude jitters for the Worldview-3 basic imagery product. Penalized splines were proposed to model the attitude jitters. After correcting the photogrammetric refraction using Saastamoinen’s model and light aberration, the RSM was built for agile satellites. The difference between RSM and RFM is consistent with attitude jitters, which is calculated using the penalized splines model and third-degree polyniomials. To fully explore the attitude jitters, a dense bundle adjustment was proposed to process 47 scenes of the Worldview-3 basic product imagery, which was provided by Johns Hopkins University Applied Physics Laboratory for the “Multi-View Stereo 3D Challenge.” Pairwise feature matching and feature tracking were adopted to generate over 16 000 tie-points (TPs), which were detected in an average of 9.38 images. The bundle adjustment residuals with RFM exhibited distortions similar to those of the attitude jitter. The experiments verified that the bundle adjustment with RFM introduced significant errors triggered by attitude jitters, with a maximum of over 5.0 pixels. The bundle adjustment with RSM could eliminate significant errors caused by attitude jitters and reduce the root mean square errors (RMSEs) from 1.12 pixels to 0.61 pixels. However, the basic product imagery of Worldview-3 exhibited errors in the interior orientation parameters. After analyzing the physical meanings of bias compensation, a self-calibration model was proposed. After comparing the shift compensation, affine compensation, self-calibration, temporal self-calibration, second-degree self-calibration, and second-degree polynomial models, the dense bundle adjustment with self-calibration was suggested because it could compensate for errors in the interior orientation parameters (IOPs) and obtain an accuracy similar to that of high-degree models. Thus, a self-calibration dense bundle adjustment with RSM compensates for the attitude jitters and errors in the IOPs, and achieves a remarkable accuracy of 0.49 pixels in the image coordinates.

Fully-structured counter-propagating optical trap sculpted by spherical aberration

Aberrations of light are commonly known as undesired effects in different applications, including optical trapping. However, here we demonstrate how to take advantage of controlled spherical aberration in order to shape extended optical trapping landscapes, fully-structured in three-dimensional (3D) space and embedding transverse as well as longitudinal electric field contributions. We numerically analyze the light field customization by the simple means of including glass plates in a counter-propagating trapping configuration, presenting sculpted intensity as well as 3D polarization ellipse structures. Experimentally, we prove the realized counter-propagating optical structure by particle velocimetry as well as the analysis of scattered light of optically guided micro-particles. Finally, we demonstrate the potential of our approach by creating extended 3D particle assemblies.