On the effect of the size of optical systems on the definition of light beams in a turbulent atmosphere

1972 ◽  
Vol 15 (4) ◽  
pp. 410-413 ◽  
Author(s):  
M. A. Kallistratova ◽  
A. I. Kon
Keyword(s):  
Turbulent Atmosphere ◽  
Optical Systems ◽  
Definition Of ◽  
Light Beams

scholarly journals AN IMPROVED AIR-DRIVEN TYPE OF ULTRACENTRIFUGE FOR MOLECULAR SEDIMENTATION

1937 ◽  
Vol 65 (4) ◽  
pp. 565-586 ◽  
Author(s):  
Johannes H. Bauer ◽  
Edward G. Pickels
Keyword(s):  
High Speed ◽  
Optical Systems ◽  
Centrifugal Field ◽  
Braking System ◽  
Axis Of Rotation ◽  
Protein Molecules ◽  
Transparent Cell ◽  
Definition Of ◽  
Operation Characteristics

1. A description is given of the construction details and operation characteristics of an improved type of air-driven ultracentrifuge operating in vacuum and suitable for the determination of sedimentation constants of protein molecules. 2. The rotor of the centrifuge is made of a forged aluminum alloy; it is oval in shape, measures 185 mm. at its greatest diameter, and weighs 3,430 gm. It carries a transparent cell located at a distance of 65 mm. from the axis of rotation and designed to accommodate a fluid column 15 mm. high. 3. The rotor has been run repeatedly over long periods at a speed of 60,000 R.P.M., which corresponds to a centrifugal force of 260,000 times gravity in the center of the cell. At this speed no deformation of the rotor nor leakage of the cell has been observed. 4. The sharp definition of sedimentation photographs taken at high speed serves to indicate the absence of detectable vibrations in the centrifuge. 5. When a vacuum of less than 1 micron of mercury is maintained in the centrifuge chamber, the rise in the rotor temperature amounts to only 1 or 2°C. after several hours' run at high speed. 6. There has been no evidence of convection currents interfering with normal sedimentation of protein molecules in the centrifugal field. 7. A driving air pressure of about 18 pounds per square inch is sufficient to maintain the centrifuge at a steady speed of 60,000 R.P.M. With a driving pressure of 80 pounds per square inch, it can be accelerated to this speed in less than 20 minutes, and also brought to rest in about the same length of time by the application of the braking system. 8. The adaptation of Svedberg's optical systems to this centrifuge for photographically recording the movement of sedimentation boundaries is described.

CONDITIONS FOR THE APPLICABILITY OF THE PRINCIPAL COMPONENT ANALYSIS TO THE CHARACTERIZATION OF THE 1/f-NOISE

2006 ◽  
Vol 06 (01) ◽  
pp. L17-L28 ◽  
Author(s):  
JOSÉ MANUEL LÓPEZ-ALONSO ◽  
JAVIER ALDA
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Random Variable ◽  
Component Analysis ◽  
Optical Systems ◽  
Data Sets ◽  
Regular Time ◽  
Pca Method ◽  
Definition Of

Principal Component Analysis (PCA) has been applied to the characterization of the 1/f-noise. The application of the PCA to the 1/f noise requires the definition of a stochastic multidimensional variable. The components of this variable describe the temporal evolution of the phenomena sampled at regular time intervals. In this paper we analyze the conditions about the number of observations and the dimension of the multidimensional random variable necessary to use the PCA method in a sound manner. We have tested the obtained conditions for simulated and experimental data sets obtained from imaging optical systems. The results can be extended to other fields where this kind of noise is relevant.

M6 formalism – generalization of the laser beam quality factor M2 to the 3D domain

2020 ◽  
Vol 9 (4) ◽  
pp. 167-173
Author(s):  
Alexander Brodsky ◽  
Natan Kaplan
Keyword(s):  
Quality Factor ◽  
Beam Quality ◽  
Three Dimensional ◽  
Single Mode ◽  
Optical Systems ◽  
Beam Quality Factor ◽  
Laser Beam Quality ◽  
Definition Of ◽  
Factor C ◽  
Focusing Lens

AbstractHere we define a theoretical basis for the generalization of the beam quality factor M2 to three-dimensional (3D) space, which we call M6 formalism. The formalism is established through the use of examples of multifocal and Axicon optical systems to illustrate discrete and continuous axial beam shaping, respectively. For the continuous case, we expand the definition of the Rayleigh range to incorporate a quality factor having both axial and transverse components $M_{{\rm{add}}}^2$ and M2. Using geometrical ray tracing simulations, a proportion factor C is found to empirically describe the axial quality factor $M_z^2$ of an optical setup including an Axicon and a paraxial focusing lens with a Gaussian single mode input beam. Using our M6 formalism depth of focus (DOF) ranges are calculated for higher M2 beams, and are shown to be in good agreement with the simulated DOF range, demonstrating the usefulness of the M6 formalism for the design of real optical systems.

scholarly journals Genuine-field modeling of partially coherent X-ray imaging systems

2020 ◽  
Vol 27 (5) ◽  
pp. 1307-1319
Author(s):  
Antonie Verhoeven ◽  
Christian Hellmann ◽  
Frank Wyrowski ◽  
Mourad Idir ◽  
Jari Turunen
Keyword(s):  
Grazing Incidence ◽  
Spectral Density Function ◽  
Imaging Systems ◽  
Optical Systems ◽  
X Ray ◽  
Partially Coherent ◽  
Partially Coherent Light ◽  
X Ray Imaging ◽  
Spatially Partially Coherent Light ◽  
Light Beams

A genuine representation of the cross-spectral density function as a superposition of mutually uncorrelated, spatially localized modes is applied to model the propagation of spatially partially coherent light beams in X-ray optical systems. Numerical illustrations based on mode propagation with VirtualLab software are presented for imaging systems with ideal and non-ideal grazing-incidence mirrors.

Sign in / Sign up

Export Citation Format

Share Document