Friday 28 March 2025
The secret life of light is full of mysteries, and scientists have been working to unravel them for centuries. One of the most fundamental aspects of light is its coherence – the way it behaves when split into different parts. While we’ve made significant progress in understanding this phenomenon, there are still many unanswered questions.
Recently, a team of researchers has taken a major step forward in our understanding of light’s coherence by developing a new technique to measure radial coherence. Radial coherence refers to the way light behaves when it’s split into different radial directions – essentially, how well light waves align with each other from one point on the surface to another.
The traditional method for measuring radial coherence involves using a complex setup involving mirrors and lenses. But this approach has its limitations – it can only measure coherence over a short range of distances, and requires precise control over the experimental conditions.
The new technique, developed by scientists at India’s Indian Institute of Technology Kanpur, uses a modified Sagnac interferometer to measure radial coherence over longer distances and with greater precision. The setup is relatively simple, involving just a few components: a laser source, a spatial light modulator, and an EMCCD camera.
The researchers tested their technique by measuring the radial coherence of two different types of radially partially coherent fields – Laguerre-Gaussian modes and radial Hermite-Gaussian modes. These modes are commonly found in optical fibers and other applications where light is used to transmit information.
The results were impressive – the new technique was able to accurately measure the radial coherence of these fields over distances of up to several millimeters, far beyond what was previously possible. The researchers also demonstrated that their technique can be used to generate a range of different radial coherence profiles, which could have important applications in fields such as optical communication and imaging.
This breakthrough has significant implications for our understanding of light’s behavior at the smallest scales. It could also lead to new technologies and techniques that take advantage of the unique properties of radially partially coherent light.
Cite this article: “Unveiling the Secrets of Lights Coherence with a New Measuring Technique”, The Science Archive, 2025.
Light, Coherence, Radial Coherence, Sagnac Interferometer, Spatial Light Modulator, Emccd Camera, Laguerre-Gaussian Modes, Hermite-Gaussian Modes, Optical Fibers, Imaging
