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Updated: Jul 16, 2026
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Quasi-light Storage for Optical Data Packets
Published on: February 6, 2014
Arbitrarily short coherence length in wave fields within finite lossless source regions
Kasimir Blomstedt1, Tero Setälä, Ari T Friberg
1Department of Engineering Physics and Mathematics, Helsinki University of Technology (TKK), P.O. Box 3500, FI-02015 HUT, Finland. kasimir@focus.hut.fi
Summary
Researchers can engineer light sources to control spatial coherence, challenging previous assumptions about field correlations and coherence length in lossless media. This opens new possibilities for manipulating wave fields.
Area of Science:
- Optics and Photonics
- Wave Physics
Background:
- Previous work suggested a universal sinc-function form for field correlations from statistically homogeneous and isotropic sources.
- A common belief posited that coherence length in lossless regions is bounded by the blackbody coherence length (approx. half the wavelength).
Purpose of the Study:
- To demonstrate the construction of stochastic source distributions for arbitrary spatial coherence control.
- To challenge established theories regarding field correlations and coherence length limitations in optical systems.
Main Methods:
- Theoretical construction of stochastic source distributions.
- Analysis of generated wave fields within prescribed finite regions.
- Investigation of field correlations and coherence properties in lossless media.
Main Results:
- It is possible to generate wave fields with any desired spatial coherence properties.
- The universal sinc-function form for field correlations is disproven for statistically homogeneous and isotropic sources in large lossless regions.
- The commonly held lower bound on coherence length by blackbody coherence length is disproven.
Conclusions:
- Stochastic source engineering offers precise control over spatial coherence.
- Established theoretical limits on field correlations and coherence length in lossless media are incorrect.
- New avenues for manipulating wave fields and their coherence properties are opened.
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