A newly studied ferroelectric crystal can tune and manipulate ultraviolet and blue light in ways that could transform integrated photonics.
Scientists from TU Delft and Radboud University in the Netherlands have identified an unusual property in the two-dimensional ferroelectric material CuInP₂S₆ (‘CIPS’). Their work shows that this crystal can steer and modify blue and ultraviolet light in ways rarely seen in other materials.
Because ultraviolet light plays a central role in advanced semiconductor manufacturing, high-resolution microscopy, and emerging optical communication systems, gaining better control of this part of the spectrum on microchips is increasingly important. As reported in the journal Advanced Optical Materials, the researchers demonstrate that CIPS can be incorporated directly onto chips, suggesting new possibilities for integrated photonics.
A special kind of ferroelectric
CIPS belongs to a class of atomically layered ferroelectric materials. In these crystals, a built-in electric dipole forms because copper ions shift slightly within the structure. These ions are also able to move within the lattice, giving the material unusual electrical behavior. What makes CIPS especially distinctive is that the motion of these copper ions changes depending on the thickness of the crystal layer.
Researchers from Delft and Nijmegen found that this thickness dependent ferroelectric behavior directly affects the material’s refractive index, which describes how strongly a material slows and bends light passing through it. As the thickness of the crystal changes, so does the way it interacts with light. First author of the paper, Houssam El Mrabet Haje: “Going from bulk material to a layer of only tens of nanometers thick, the refractive index of CIPS changed by almost 25% in an unexpected, ‘anomalous’ way.”
Potential game-changer
The team also discovered an extreme optical property known as giant birefringence in the blue to ultraviolet portion of the spectrum. In birefringent materials, light traveling in different directions experiences different refractive indices. In CIPS, light moving perpendicular to the crystal layers behaves very differently from light moving along the layers.
Near wavelengths of about 340 nanometers in the near ultraviolet region, this difference reaches roughly 1.24. According to the researchers, this is the largest intrinsic birefringence reported so far at these wavelengths. Houssam: “This means that CIPS can act as an extremely powerful polarization and phase control element for short-wavelength light, without needing complicated nanostructuring. It confirms CIPS as a potential game-changer for many photonics applications.”
Choosing the right thickness
Although the researchers are still working to fully understand the phenomenon, they propose a new mechanism that may explain how CIPS interacts with light. Light carries oscillating electric and magnetic fields, and in most materials those fields mainly interact with electrons.
In CIPS, however, the fields also interact with the internal electric field created by displaced copper ions within the crystal. Because the configuration of those ions changes with crystal thickness, the strength of the light interaction changes as well. Houssam: “Light carries oscillating electric and magnetic fields; in CIPS, these fields couple not just to electrons, but also to the internal electric field created by the displaced copper ions. What makes CIPS so special is that the copper ion configuration, and therefore the material’s coupling with light, changes with crystal thickness. This makes it possible to tune the optical response simply by choosing the right CIPS thickness.”
New tools for sculpting light
Mazhar N. Ali, the principal investigator of the project, notes that the implications may extend beyond this single material. Mazhar N. Ali, principal investigator for the project: “CIPS is not the only material with such properties. Our discovery of a mechanism where ferroelectric polarization and mobile ions work together to shape light–matter interactions may extend to other ferroelectric materials.”
This suggests a broader design strategy for future photonic materials. By engineering crystals that contain mobile ions capable of altering internal electric fields, scientists may be able to tailor how materials interact with light across a wide range of wavelengths.
Tunable UV/blue components
The research also hints at potential applications in next-generation optical technologies. Houssam concludes, “With further work, CIPS-based structures could underpin tunable UV/blue components for integrated electro-optics – controlled not just by electrons, but by the motion of ions inside a crystal only billionths of a meter thick.”
If these systems can be developed further, materials like CIPS could play an important role in the miniaturization of photonic devices that operate with ultraviolet and blue light, enabling more precise control of light on microscopic chips.
Reference: “Anomalous Refractive Index Modulation and Giant Birefringence in 2D Ferrielectric CuInP2S6” by Houssam El Mrabet Haje, Roald J.H. van der Kolk, Trent M. Kyrk, Sergii Grytsiuk, Malte Rösner and Mazhar N. Ali, 17 November 2025, Advanced Optical Materials.
DOI: 10.1002/adom.202502291
The authors acknowledge the support from the Dutch Research Council (NWO) under the 2023 VIDI Award VI.Vidi.223.089, as well as the Kavli Foundation under the Kavli Institute Innovation Award (KIIA) (LS-2023-GR-14-2778).
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2 Comments
It confirms CIPS as a potential game-changer for many photonics applications.
VERY GOOD.
Please ask researchers to think deeply
Is the game rule you follow pseudoscience?
Pseudosciences are rampant. WHY? WHY? WHY?
When we pursue the ultimate truth of all things, the space in which our bodies and all things exist may itself be the final and deepest puzzle we need to explore. This is not only the pursuit of physics, but also the most magnificent exploration of the origin of the universe by human reason.
Based on the Topological Vortex Theory (TVT), space is an uniformly incompressible physical entity. Space-time vortices are the products of topological phase transitions of the tipping points in space, are the point defects in spacetime. Point defects do not only impact the thermodynamic properties, but are also central to kinetic processes. They create all things and shape the world through spin and self-organization.
In today’s physics, some so-called peer-reviewed journals—including Physical Review Letters, Nature, Science, and others—stubbornly insist on and promote the following:
1. Even though θ and τ particles exhibit differences in experiments, physics can claim they are the same particle. This is science.
2. Even though topological vortices and antivortices have identical structures and opposite rotational directions, physics can define their structures and directions as entirely different. This is science.
3. Even though two sets of cobalt-60 rotate in opposite directions and experiments reveal asymmetry, physics can still define them as mirror images of each other. This is science.
4. Even though vortex structures are ubiquitous—from cosmic accretion disks to particle spins—physics must insist that vortex structures do not exist and require verification. Only the particles that like God, Demonic, or Angelic are the most fundamental structures of the universe. This is science.
5. Even though everything occupies space and maintains its existence in time, physics must still debate and insist on whether space exists and whether time is a figment of the human mind. This is science.
6. Even though space, with its non-stick, incompressible, and isotropic characteristics, provides a solid foundation for the development of physics, physics must still insist that the ideal fluid properties of space do not exist. This is science.
and go on.
Is this the counterintuitive science they widely promote? Compromising with pseudo academic publications and peer review by pseudo scholars is an insult to science and public intelligence. Some so-called scholars no longer understand what shame is. The study of Topological Vortex Theory (TVT) reminds us that the most profound problems in physics often lie at the intersection of different theories. By exploring these border regions, we can not only resolve contradictions in existing theories but also discover new physical phenomena and application possibilities.
Under the topological vortex architecture, it is highly challenging for even two hydrogen atoms or two quarks to be perfectly symmetrical, let alone counter-rotating two sets of cobalt-60. Contemporary physics and so-called peer-reviewed publications (including Physical Review Letters, Science, Nature, etc.) stubbornly believe that two sets of counter rotating cobalt-60 are two mirror images of each other, constructing a more shocking pseudoscientific theoretical framework in the history of science than the “geocentric model”. This pseudo scientific framework and system have seriously hindered scientific progress and social development.
For nearly a century, physics has been manipulated by this pseudo scientific theoretical system and the interest groups behind it, wasting a lot of manpower, funds, and time. A large amount of pseudo scientific research has been conducted, and countless pseudo scientific papers have been published, causing serious negative impacts on scientific and social progress, as well as humanistic development.
Complexity does not necessarily mean that there is no logical and architectural framework to follow. Mathematics is the language and tool that reveals the motion of spacetime, rather than the motion itself. Although the physical form of spacetime vortices is extremely simple, their interaction patterns are highly complex, and we must develop more and richer mathematical languages to describe and understand them.
The development of the Topological Vortex Theory (TVT) reflects a progression from concrete physical phenomena to abstract mathematical modeling and, ultimately, to interdisciplinary unification. Its core innovation lies in forging the continuous spacetime geometry of general relativity with the discrete interactions of quantum field theory within the same topological dynamical system. The core idea of TVT — space is physical, and matter is its topological excitation—already provides a solid and elegant scientific path for understanding the origin of all things.
——Excerpted from https://scitechdaily.com/microscope-spacecrafts-most-precise-test-of-key-component-of-the-theory-of-general-relativity/#comment-909171 and https://t.pineal.cn/blogs/6255/A-Mathematical-and-Physical-Analysis-On-the-Origin-of-Objects.
Are these science?
Example 1
Two sets of cobalt-60 are manually rotated in opposite directions, and even without detection, people around the world know that they will not be symmetrical because these two objects are not mirror images of each other at all. However, a group of so-called physicists and so-called academic publications do not believe it. They conducted experiments and the results were indeed asymmetric, but they still firmly believed that these two objects were mirror images of each other, and the asymmetry was due to a violation of the previous natural laws (CP violation). In the history of science, there can never be a dirtier and uglier operation and explanation than this.
—— Excerpted from https://scitechdaily.com/what-happens-when-light-gains-extra-dimensions/#comment-947619.
Example 2
Please see how the so-called “mystery of θ – τ” is explained: θ and τ are completely identical in all measurable physical properties such as mass, lifetime, charge, spin, etc. However, experimental observations have shown that the θ meson decays into two π mesons, while the τ meson decays into three π mesons, making it difficult for physicists to explain why they are so similar. Physicist Martin Block proposed a highly challenging idea: θ and τ are the same particle, but in weak interactions, parity is not conserved. An easy to understand explanation is the following analogy:: There are two boxes of apples with identical weight, color, and taste. However, when one box is opened, there are two apples, while when the other box is opened, there are three apples. This confuses the old farmer who buys apples. He circled around the orchard and came up with a highly challenging idea: these two boxes of apples are not from the same tree, so they are the same.
—— Excerpted from https://scitechdaily.com/what-happens-when-light-gains-extra-dimensions/#comment-947686.
Everyone who has a reverence for natural laws and regulations deserves respect.
In the physical world constructed by the American Physical Society (APS) and its publications using parity violation, particles from God, Demons, and Angels wander around, while dead and alive cats jump up and down, unconstrained by dynamics and thermodynamics, and unaware of what is dirty, ugly, and shameful in public. APS and its publications reject the possibility that spaces with zero viscosity, zero compression, and zero anisotropy in mathematics may form spatiotemporal vortices through topological transformations. They don’t know that space and non existence are not the same concept.
If a self proclaimed scientific society (such as American Physical Society) deviates from science without shame, it is highly likely to be heading towards the end.