This breakthrough opens up exciting possibilities for use in routing optical signals, sensing and taking measurements. Controlling light absorption in solids could lead to faster and more efficient optical communication systems. This important breakthrough was published in the prestigious journal Nature Communications.
There are four states of matter in everyday life: solid, liquid, gas and plasma. Solids can be further divided into two types, amorphous and crystalline, based on their internal structure. A crystalline solid consists of particles arranged in a regular, repeating three-dimensional pattern. Meanwhile, an amorphous solid — like rubber, plastic or glass — has a random, disorganized structure without a definite pattern.
The traditional view is that this lack of ordered structure means amorphous solids cannot exhibit dichroism —where a material absorbs light differently depending on the light’s polarization (the direction it oscillates in). However, Professor Bhardwaj’s recent research challenges this view. He demonstrates that intrinsic dichroism can indeed exist in amorphous solids.
Together with his PhD students, Ashish Jain and Jean-Luc Bégin, Professor Bhardwaj investigated how helical light with different polarizations interacts with solid samples. To do this, the team measured how much light the materials absorbed. They used light beams with specific properties, such as varying polarization types and sets of helical waves with a defined revolving motion, to explore how these factors affect light absorption in materials.
“The hardest part of this breakthrough was changing the established perceptions in physics. For decades, it was believed that amorphous solids had isotropic properties and that light’s optical phase was insignificant. We faced skepticism and countless rechecks, but our results proved that a paradigm shift was possible,” explains Professor Bhardwaj.
Developing a theory to explain their findings posed another significant challenge. The team rigorously tested their models to ensure they aligned with the experimental results. “The whole community asked, ‘Did you do this? Did you try that?’” Ashish recalled. After more than two years of thorough experiments and countless discussions, they succeeded in building a sound theoretical framework.
Despite the difficulties, their persistence paid off, resulting in a qualitative and partly quantitative model that could explain what they observed. This model marks a significant shift in understanding asymmetric light interactions.
This research allows precise control over how much light a solid absorbs. That paves the way for advancements in photonic devices, like faster optical switches for communications, improved sensors for detecting material properties and enhanced optical measurement tools. These innovations could lead to more efficient data transmission and new light-phase-based measurement technologies.
Choosing Nature Communications to publish this discovery was a strategic decision to ensure the research reached a broad audience. With its wide readership and high visibility, this open-access journal maximizes the impact of the findings. It also stimulates discussions that could shift opinions in the scientific community.
Students were essential for this breakthrough, highlighting the crucial role that students play in advancing scientific knowledge. Ashish and Jean-Luc began their PhDs focusing on two distinct topics, but their shared interest in helical light brought them together. Looking ahead, Ashish will start a new job as an optical scientist in a company while continuing to work with Professor Bhardwaj. Jean-Luc will embark on a postdoctoral fellowship, doing advanced research on gases. As Jean-Luc notes, “We will continue to explore new ideas together.”
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