A spot,that is distribution of optical field,was recorded by positive photoresist (PMMA) located at object plane under the condition of a condenser zone plate which center wavelength is 3.2nm and a pinhole of 30μm diameter combination. The diameters of Airy diffraction pattern and spatial coherence area were obtained from the spot.
Based on the ray theory, integral expression was derived for the spatial coherence matrix of the sound pressure and the particle velocity in a stratified ocean with dipole noise sources homogenously distributed on the surface.
Starting from the propagation law of partially coherent light and using a typical partially coherent light, i.e., Gaussian Schell-model (GSM) beam describing the multimode laser in practice, I present in this dissertation the research results on vectorial partially coherent light, spectral changes of partially coherent light passing through optical element, spectral switch of partially coherent light diffracted by an aperture, and the spectral anomaly of diffracted fully spatially coherent light by an aperture.
More recently, singular optics has been extended to polychromatic cases by Professor Wolf and his co-workers, in which they have showed that drastic spectral changes occur in the vicinity of intensity zeros in the focal region of polychromatic, spatially coherent, converging spherical waves, i.e. the spectrum is redshifted at some points, blueshifted at some other points, and is split into two peaks elsewhere.
By using the theory of partially coherent light,the multi mode laser beams behaving like Gaussian Schell model(GSM) beams have been represented by the superposition of spatially coherent modes,which may be mutually correlated. The analytical expressions for the mode coherence cofficients have been given in the rectangular coordinate system. Furthermore,based on the M 2 factor concept,the theory of the mode decomposition of multi mode laser beams has been built up for the general case,where the mode correlation is considered.
Finally the thesis uses different spatial coherent functions and changes decay factors to analyze the effect of spatial correlation on the distribution of the mode contribution factors and the validity of Ritz vectors.
In addition, some calculation comparisons are given in the selection of the modal numbers in frequency-domain analysis, the influence of spatial coherent function, the effect of modal damping ratio and the cross terms of all computing modals.
This article introduce the principle of Minimum-Norm method in detail, and remonstrate the fact that the Minimum-Norm method can not resolve the spatial coherent signals through simulation.
The average spatial coherent characteristics of laser light transmittingtlirougii a multimode fiber may be determined by means of measuring the contrast of speckle patterns projected from a multiniode fiber, and a methods for measurement of characteristics of laser light passing through a multiniode fiber is given.
By observing the flame distribution of a burning flame ring, this experiment vividly shows the condition of the two oppositely travelling wave trains which cohere in the space of the ring and form standing, waves.
Based on electromagnetic theory, a computing model of the Talbot interferometer is established with the temporal and the spatial coherence taken into account and with the turning angle of the reflectors as a critical parameter.
This algorithm is based on the interrelation between the spatial coherence of structural fragments in nanoparticles and the geometric connection in the corresponding associated bundle.
Nonlinear resonance induced by the higher spatial coherence harmonics
The resonance was caused by the higher spatial coherence harmonics on the test transition.
Such parameters can be the spatial coherence of incident radiation, the direction of the momentum transfer relative to the specular diffraction plane, or the X-ray wavelength.
The poorly studied, spatially coherent large-scale structures on the solar surface characterized by sectorial-hemispheric asymmetry may be produced by ultralow-frequency nonlinear oscillations of the Sun.
If this ratio is more than 2, the above deviation does not exceed values permissible for devices using spatially coherent light (e.g., for free-space optical communication systems).
Spatially coherent radiation from a coaxial free-electron laser with a resonator composed of one-dimensional and two-dimensional
It is shown that cw spatially coherent lasing may be achieved with an oversize parameter of the order of 50 with the excitation of supermodes comprising a set of " cold" waveguide modes.
It is demonstrated that this design provides for a possibility of obtaining spatially coherent radiation from a sheet electron stream with the cross size exceeding the wavelength by several orders of magnitude.
The coherence properties of a Q-switched frequency-doubled Nd:YAG laser havebeen investigated by a Michelson interferometer and photography.In this experi-mental study,coherence degree |γ_(τ)| was measured as a function of pathlengthdifference and of ratio of input energy to threshold input energy.The coherencelength measured was 40mm at a ratio of input energy to threshold energy of 3.2.Spatial coherence of beam was deduced from the fringes formed by a Michelson inter-ferometer in which the laser beam interferes...
The coherence properties of a Q-switched frequency-doubled Nd:YAG laser havebeen investigated by a Michelson interferometer and photography.In this experi-mental study,coherence degree |γ_(τ)| was measured as a function of pathlengthdifference and of ratio of input energy to threshold input energy.The coherencelength measured was 40mm at a ratio of input energy to threshold energy of 3.2.Spatial coherence of beam was deduced from the fringes formed by a Michelson inter-ferometer in which the laser beam interferes with itself after being rotated 180°,Theexperimental results were physically interpreted.
This paper presents coherence concepts including time coherence, spatial coherence and complex correlation function.
In the present paper we have suggested a method of measuring the spatial coherence of light beam—the holographic shearing interferometer, and also given the experimental measured resuIts of the spatial coherence of copper vapor laser beam.