Topic
Wolf effect
About: Wolf effect is a research topic. Over the lifetime, 38 publications have been published within this topic receiving 1719 citations. The topic is also known as: Wolf shift.
Papers
TL;DR: It is demonstrated that by introducing a periodic microstructure into such a polar material (SiC) a thermal infrared source can be fabricated that is coherent over large distances (many wavelengths) and radiates in well defined directions.
Abstract: A thermal light-emitting source, such as a black body or the incandescent filament of a light bulb, is often presented as a typical example of an incoherent source and is in marked contrast to a laser. Whereas a laser is highly monochromatic and very directional, a thermal source has a broad spectrum and is usually quasi-isotropic. However, as is the case with many systems, different behaviour can be expected on a microscopic scale. It has been shown recently that the field emitted by a thermal source made of a polar material is enhanced by more than four orders of magnitude and is partially coherent at a distance of the order of 10 to 100nm. Here we demonstrate that by introducing a periodic microstructure into such a polar material (SiC) a thermal infrared source can be fabricated that is coherent over large distances (many wavelengths) and radiates in well defined directions. Narrow angular emission lobes similar to antenna lobes are observed and the emission spectra of the source depends on the observation angle--the so-called Wolf effect. The origin of the coherent emission lies in the diffraction of surface-phonon polaritons by the grating.
1,491 citations
TL;DR: In this paper, the effects of multiple scattering on the spectrum of the scattered light are elucidated from comparison with the corresponding results derived previously under the first-order Born approximation, and it is observed that the magnitude of the changes in the spectrum is enhanced in the forward-scattering directions.
Abstract: Changes in the spectrum of light scattered by spatially random media are investigated theoretically within the accuracy of the first-order Rytov approximation. Such a phenomenon is analogous to that treated in recent studies on the correlation-induced spectral changes that are often referred to as the Wolf effect. In particular, the effects of multiple scattering on the spectrum of the scattered light are elucidated from comparison with the corresponding results derived previously under the first-order Born approximation. As a result, it is observed that the magnitude of the changes in the spectrum is enhanced in the forward-scattering directions owing to the effects of multiple scattering.
44 citations
TL;DR: In this paper, the authors derived expressions for the spectrum of the field produced by planar, secondary Gaussian Schell-model sources after propagation in free-space, homogeneous dispersive media, and graded-index fibers.
Abstract: We derive expressions for the spectrum of the field produced by planar, secondary Gaussian Schell-model sources after propagation in free-space, homogeneous dispersive media, and graded-index fibers. Our results show, for the first time to our knowledge, the development of correlation-induced spectral changes (the Wolf effect) as a function of the propagation distance from the source plane. An important result of our study is the prediction of the enhancement of the Wolf effect for propagation in media of index of refraction larger than unity. In the case of graded-index fibers having a parabolic index profile, the source spectrum is shown to reproduce periodically at distances at which such fibers image the source.
34 citations
TL;DR: In this paper, a comprehensive representation of the Wolf effect in propagation both in free space and after a lens for an outstanding class of partially coherent beams, namely Gaussian Schell-model beams, is presented.
Abstract: We give a comprehensive representation of the Wolf effect in propagation both in free space and after a lens for an outstanding class of partially coherent beams, namely Gaussian Schell-model beams. We characterize the correlation-induced spectral changes, throughout the whole space, by means of isoshift lines and transverse shift profiles. The maximum value of the frequency blueshift, occurring on the optical axis, is also calculated.
31 citations
TL;DR: In this article, an expression for the statistically-averaged spectral density of light produced by scattering from spatially random media within the accuracy of the second-order Born approximation is derived, and the effects of multiple scattering on the resultant field are investigated by some numerical examples.
28 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2018 | 3 |
| 2012 | 1 |
| 2010 | 1 |
| 2006 | 1 |
| 2005 | 2 |