23 papers · ranked by Valyu relevance
Klaus D. Mielenz
This paper focuses on unresolved or poorly documented issues pertaining to Fresnel’s scalar diffraction theory and its modifications. In Sec. 2 it is pointed out that all thermal sources used in practice are finite in size and errors can result from insufficient coherence of the optical field. A quarter-wave criterion…
Thomas E. Weirich, S.-L. Zheng
A paper-based virtual X-ray diffraction experiment, which is based on the right-angle condition for constructive interference, allows the implications of Bragg’s law to be studies in a simple way.
T. Santhanakrishnan, R. Rajesh, Ram Lochan Awasthi, C. V. Sreehari
An optical method for simultaneous generation and detection of diffraction of light around the edges of photodetectors is reported in this paper along with its application for vibration sensing. The method makes use of an innovative illumination of light beam in which the laser light is made to incident at the…
Shyamal Biswas, Rhitabrata Bhattacharyya, Saugata Bhattacharyya
We have analytically explored the Rayleigh-Sommerfeld scalar diffraction for oblique incidence. We have explicitly derived the Fraunhofer diffraction formulae for oblique incidence of plane scalar wave on various apertures, such as single-slit, circular aperture, and diffraction grating. Such derivations in the…
Martin Fally
and consequences Authors: ['Martin Fally'] Based on the seminal work by John T. Sheridan [1] we discuss the usefulness and validity of simple diffraction theories frequently used to determine and characterize optical holographic gratings. Experimental investigations obtained in recent years highlight the correctness of…
Georg Heuberger, Jürgen Klepp, Jinxin Guo, Yasuo Tomita + 1 more
'Martin Fally'] We experimentally characterize the positions of the diffraction maxima of a phase grating on a screen, for laser light at oblique incidence (so-called off-plane diffraction or conical diffraction). We discuss the general case of off-plane diffraction geometries and derive basic equations for the…
Reinaldo J. Gleiser
The speed of light in a vacuum is one of the most fundamental quantities in modern physics. It is well known, however, and there has been ample debate in the literature, that while the two way speed of light is experimentally well defined, the one way speed of light cannot be measured as long as speed is conceived as…
Morteza Jafari Siavashani, Elyas Nasimdoust, Parviz Elahi, Mohammad Taghi Tavassoly + 1 more
'Mohammad Taghi Tavassoly' 'Ali-Reza Moradi'] Optical diffractometry (OD) using a phase step is an alternative for interferometry, further, has least sensitivity to environmental vibrations. Therefore, OD has found numerous interesting metrological and technological applications. OD utilizes a phase step to detect the…
Agnieszka Siemion
Diffractive optical elements are well known for being not only flat but also lightweight, and are characterised by low attenuation. In different spectral ranges, they provide better efficiency than commonly used refractive lenses. An overview of the recently invented terahertz optical structures based on diffraction…
Roland Donatiello, Mustaqim Siddi Que Iskhandar, Md Kamrul Hasan, Philipp Kästner + 7 more
'Philipp Kästner' 'Muhammad Hasnain Qasim' 'Jiahao Chen' 'Shilby Baby' 'Basma Elsaka' 'Guilin Xu' 'Hartmut Hillmer' 'Qifa Zhou'] An innovative glass substrate surface technology including integrated micro-electro-mechanical systems (MEMS) is presented as an advanced light modulation, heat control, and energy management…
Fabrizio Logiurato, Beniamino Danese, L M Gratton, Stefano Oss
uantum theory is introduced in many books by means of an example widely ecognized as paradigmatic: the double-slit experiment (see, e.g., Refs. 1-4). Light, after travelling and behaving as a wave, manifests itself on the detection screen as a stream of corpuscles. According to Feynman, it is absolutely impossible to…
Yuwei Liu, Xiaoli Zhu, Yulin Gao, Wenhai Zhang + 18 more
'Lai Wei' 'Zuhua Yang' 'Qiangqiang Zhang' 'Feng Qian' 'Yong Chen' 'Weihua He' 'Yinzhong Wu' 'Zhuoyang Yan' 'Yilei Hua' 'Yidong Zhao' 'Mingqi Cui' 'Rong Qiu' 'Weimin Zhou' 'Yuqiu Gu' 'Baohan Zhang' 'Changqing Xie' 'Leifeng Cao'] Advances in the fundamentals and applications of diffraction gratings have received much…
Denis Tikhonov
Here, we present a new approach for obtaining radial distribution functions (RDF) from the electron diffraction data using a regularized weighted sine least-squares spectral analysis (rwsLSSA). It allows for explicitly transferring the measured experimental uncertainties in the reduced molecular scattering function to…
Kokou B. Dossou
We consider the spectral response of moving diffraction gratings, in which the incident light extends over a broad angular range and where the diffracted light is observed from a specific angle. We show that the dispersion relation between the frequency perceived by an observer who is looking at a moving grating and…
Robert Bücker, Pascal Hogan-Lamarre, Pedram Mehrabi, Eike C. Schulz + 7 more
We describe a new method for serial electron diffraction of protein nano-crystals using a conventional S/TEM microscope. Here, randomly dispersed crystals are mapped, and dose-efficient diffraction patterns measured at each identified position for structure determination. This fully automated workflow is suitable for…
Steve P. Meisburgera, Nozomi Andob
Diffuse scattering is a promising method to gain additional insight into protein dynamics from macro-molecular crystallography (MX) experiments. Bragg intensities yield the average electron density, while the diffuse scattering can be processed to obtain a three-dimensional reciprocal space map, that is further…
Steve P. Meisburger, Nozomi Ando
Diffuse scattering is a powerful technique to study disorder and dynamics of macromolecules at atomic resolution. Although diffuse scattering is always present in diffraction images from macromolecular crystals, the signal is weak compared with Bragg peaks and background, making it a challenge to visualize and measure…
Niko Vlahakis, Arden Clauss, Jose Rodriguez
High-energy electrons induce sample damage and motion at the nanoscale to fundamentally limit determination of molecular structures by electron diffraction. Using fast event-based electron counting (EBEC) detectors, we characterize electron beam-induced crystal lattice reorientations (BIR) that appear to broadly affect…
Michael E. Wall, Alexander M. Wolff, James S. Fraser
X-ray crystallography is experiencing a renaissance as a method for probing the protein conformational ensemble. The inherent limitations of Bragg analysis, however, which only reveals the mean structure, have given way to a surge in interest in diffuse scattering, which is caused by structure variations. Diffuse…
Steve P. Meisburger, David A. Case, Nozomi Ando
Protein dynamics are integral to biological function, yet few techniques are sensitive to collective atomic motions. A long-standing goal of X-ray crystallography has been to combine structural information from Bragg diffraction with dynamic information contained in the diffuse scattering background. However, the…
Zhen Su, Medhanjali Dasgupta, Frédéric Poitevin, Irimpan I. Mathews + 4 more
Protein structure and dynamics can be probed using X-ray crystallography. Whereas the Bragg peaks are only sensitive to the average unit-cell electron density, the signal between the Bragg peaks -- diffuse scattering -- is sensitive to spatial correlations in electron-density variations. Although diffuse scattering…
Sarthak Patnaik
We know that the diffusion is defined as the movement of molecules under a potential gradient. It is characterized by the diffusion coefficient. Diffusion coefficient determination can be done via various techniques, but in this paper, we have had a broad look at interferometry based optical methods for diffusion…
D. Chirkin, M. Rongen
> The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole with 5160 photomultipliers to detect Cherenkov light from charged relativistic particles. The experiment pursues a wide range of scientific questions ranging from particle physics such as neutrino oscillations…