The extraction of the Green’s function and the generalized optical theorem
نویسندگان
چکیده
The relationship between the Green’s function and the average cross-correlation of a diffuse field is shown to be equivalent to the generalized optical theorem. The correspondence to the usual optical theorem holds for the extraction of the imaginary component of the Green’s function at the source for general linear scalar systems from the autocorrelation of field fluctuations. The imaginary component of the Green’s function at the source is finite and shown to be related to the loss in energy (acoustic waves) and probability (quantum mechanics) due to radiation and attenuation.
منابع مشابه
Field Fluctuations, Imaging with Backscattered Waves, a Generalized Energy Theorem, and the Optical Theorem
We show the connection between four aspects of wave propagation: the autocorrelation of field fluctuations, imaging with backscattered waves, a theorem for energy flow, and the generalized optical theorem. The autocorrelation of field fluctuations can be used to extract the imaginary component of the Green’s function at the source. The Green’s function usually is singular at the source, but the...
متن کاملThe cancellation of spurious arrivals in Green’s function extraction and the generalized optical theorem
The extraction of the Green’s function by cross-correlation of waves recorded at two receivers nowadays finds much application. We show that for an arbitrary isolated scatterer, the cross-terms of scattered waves give an unphysical wave with an arrival time that is independent of the source position. This constitutes a paradox because theory predicts that such spurious arrivals do not arise, af...
متن کاملQuantum modeling of light absorption in graphene based photo-transistors
Graphene based optical devices are highly recommended and interested for integrated optical circuits. As a main component of an optical link, a photodetector based on graphene nano-ribbons is proposed and studied. A quantum transport model is presented for simulation of a graphene nano-ribbon (GNR) -based photo-transistor based on non-equilibrium Green’s function method. In the proposed model a...
متن کاملn seismic interferometry , the generalized optical theorem , and the cattering
We have analyzed the far-field approximation of the Green’s function representation for seismic interferometry. By writing each of the Green’s functions involved in the correlation process as a superposition of a direct wave and a scattered wave, the Green’s function representation is rewritten as a superposition of four terms. When the scattered waves are modeled with the Born approximation, i...
متن کاملOn seismic interferometry, the generalized optical theorem, and the scattering matrix of a point scatterer
We have analyzed the far-field approximation of the Green’s function representation for seismic interferometry. By writing each of the Green’s functions involved in the correlation process as a superposition of a direct wave and a scattered wave, the Green’s function representation is rewritten as a superposition of four terms. When the scattered waves are modeled with the Born approximation, i...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008