This major scientific advance has implications for many fields, including energy-efficient computers and quantum technology.
Until recently, physicists widely believed that it was impossible to compress light below the so-called diffraction limit, except when utilizing metal nanoparticles, which also absorb light. As a result, it seemed to be impossible to compress light strongly in dielectric materials like silicon, which are essential for information technologies and had the significant advantage of not absorbing light. Interestingly, it was theoretically shown that the diffraction limit does not apply to dielectrics back in 2006. However, no one has been able to demonstrate this in the actual world due to the fact that it requires such complex nanotechnology that no one has yet been able to create the required dielectric nanostructures.
A research team from the Technical University of Denmark (DTU) has created a device known as a “dielectric nanocavity” that successfully concentrates light in a volume 12 times smaller than the diffraction limit. The finding is groundbreaking in optical research and was recently published in the journal Nature Communications.
“Although computer calculations show that you can concentrate light at an infinitely small point, this only applies in theory. The actual results are limited by how small details can be made, for example, on a microchip,” says Marcus Albrechtsen, Ph.D.-student at DTU Electro and the first author of the new article.
Optical nanocavities are structures that have been specially designed to retain light so that it does not travel normally but is tossed back and forth as if two mirrors were facing each other. The closer the mirrors are to one other, the more intense the light between them gets. For this experiment, the researchers created a bowtie structure, which is particularly effective in squeezing photons together due to its unique shape.
The diffraction limit
The theory of the diffraction limit describes that light cannot be focused to a volume smaller than half the wavelength in an optical system – for example, this applies to the resolution in microscopes.
However, nanostructures can consist of elements much smaller than the wavelength, which means that the diffraction limit is no longer a fundamental limit. Bowtie structures, in particular, can compress the light into very small volumes limited by the sizes of the bowtie and, thus, the quality of the nanofabrication.
When the light is compressed, it becomes more intense, enhancing interactions between light and materials such as atoms, molecules, and 2D materials.
Dielectric materials are electrically insulating. Glass, rubber, and plastic are examples of dielectric materials, and they contrast with metals, which are electrically conductive.
An example of a dielectric material is silicon, which is often used in electronics but also in photonics.
Interdisciplinary efforts and excellent methods
The nanocavity is made of silicon, the dielectric material on which most advanced modern technology is based. The material for the nanocavity was developed in cleanroom laboratories at DTU, and the patterns on which the cavity is based are optimized and designed using a unique method for topology optimization developed at DTU. Initially developed to design bridges and aircraft wings, it is now also used for nanophotonic structures.
“It required a great joint effort to achieve this breakthrough. It has only been possible because we have managed to combine world-leading research from several research groups at DTU,” says associate professor Søren Stobbe, who has led the research work.”
Important breakthrough for energy-efficient technology
The discovery could be decisive for developing revolutionary new technologies that may reduce the amount of energy-guzzling components in data centers, computers, telephones, etc.
The energy consumption for computers and data centers continues to grow, and there is a need for more sustainable chip architectures that use less energy. This can be achieved by replacing electrical circuits with optical components. The researchers’ vision is to use the same division of labor between light and electrons used for the Internet, where light is used for communication and electronics for data processing. The only difference is that both functionalities must be built into the same chip, which requires that the light be compressed to the same size as the electronic components. The breakthrough at DTU shows that it is, in fact, possible.
“There is no doubt that this is an important step to developing a more energy-efficient technology for, e.g., nanolasers for optical connections in data centers and future computers – but there is still a long way to go,” says Marcus Albrechtsen.
The researchers will now work further and refine methods and materials to find the optimal solution.
“Now that we have the theory and method in place, we will be able to make increasingly intense photons as the surrounding technology develops. I am convinced that this is just the first of a long series of major developments in physics and photonic nanotechnology centered around these principles,” says Søren Stobbe, who recently received the prestigious Consolidator Grant from the European Research Council of € 2 million for the development of a completely new type of light source based on the new cavities.
DREAM complex could hold key to fighting cancer and living longer
DNA may be the stuff of life, but if it isn't repaired in our bodies on a regular basis, it can lead to diseases that can cause some pretty unpleasant types of death. DNA [...]
A Promising New Pathway in the Battle Against Aggressive Prostate Cancer
Neuronal Molecule Makes Prostate Cancer More Aggressive Researchers discover a potential therapeutic avenue against an aggressive form of prostate cancer. Prostate cancer is the second most common cancer and the second leading cause of [...]
Nasal Vaccines: Stopping the COVID-19 Virus Before It Reaches the Lungs
The Pfizer-BioNTech and Moderna mRNA vaccines have played a large role in preventing deaths and severe infections from COVID-19. But researchers are still in the process of developing alternative approaches to vaccines to improve [...]
NASA Tracking a Huge, Growing Anomaly in Earth’s Magnetic Field – with video
NASA is actively monitoring a strange anomaly in Earth's magnetic field: a giant region of lower magnetic intensity in the skies above the planet, stretching out between South America and southwest Africa. This vast, developing [...]
New, Better Models Show How Infectious Diseases Like COVID-19 Spread
Infectious diseases such as COVID-19 can spread rapidly across the globe. Models that can predict how such diseases spread will strengthen national surveillance systems and improve public health decision-making. The COVID-19 pandemic has emphasized the [...]
Human Antibodies Discovered That Can Block Multiple Coronaviruses Including COVID-19
Results from a Scripps Research and UNC team pave the way for a vaccine and therapeutic antibodies that could be stockpiled to fight future coronavirus pandemics. A team of scientists from Scripps Research and [...]
Nanotechnology could be used to treat lymphedema
The human body is made up of thousands of tiny lymphatic vessels that ferry white blood cells and proteins around the body, like a superhighway of the immune system. It's remarkably efficient, but if [...]
DNA Nanotechnology Tools – From Design to Applications
Suite of DNA nanotechnology devices engineered to overcome specific bottlenecks in the development of new therapies, diagnostics, and understanding of molecular structures. DNA nanostructures with their potential for cell and tissue permeability, biocompatibility, and [...]
Regenerating bone with deer antler stem cells
Scientists from a collection of Chinese research institutions collaborated on a study of organ regeneration in mammals, finding deer antler blastema progenitor cells are a possible source of conserved regeneration cells in higher vertebrates. [...]
AI Takes On Cancer: Analysis of Mutations Could Lead to Improved Therapy
Cancer is a complex and diverse disease, and its range of associated mutations is vast. The combination of these genomic changes in an individual is referred to as their “mutational landscape.” These landscapes vary [...]
Exposing tumours to bacteria converts immune cells to cancer killers
New research on inflammation could lead to better treatments to improve outcomes for people with advanced or previously untreatable cancers. Introducing bacteria to a tumour’s microenvironment creates a state of acute inflammation that triggers [...]
Smart nanotechnology for more accurate delivery of insulin
More efficient and longer lasting glucose-responsive insulin that eliminates the need for people with type 1 diabetes to measure their glucose levels could be a step closer thanks to a Monash University-led project. Published [...]
Efficiently Harvesting Rare Earth Elements From Wastewater Using Exotic Bacteria
The novel strains of cyanobacteria exhibit a fast and efficient “biosorption” of rare earth elements, making recycling possible. Rare earth elements (REEs) are a set of 17 metallic elements that possess similar chemical properties. [...]
Resisting Treatment: Cancer Cells Shrink or Super-Size To Survive
A new approach to image analysis has uncovered how cancer cells manipulate their size as a means of resisting treatment. Researchers have discovered that cancer cells are capable of either shrinking or super-size themselves [...]
New Research Explains Why Children Avoid Severe COVID-19 Symptoms
According to new research, children exhibit a robust initial immune response to the coronavirus, however, they are unable to transfer this response to long-lasting memory T cells like adults do. Researchers led by scientists [...]
Scientists Unravel Protein Map of Mitochondria
A new study sheds light on the organization of proteins within mitochondria. Mitochondria, the “powerhouses” of cells, play a crucial role in the energy production of organisms and are involved in various metabolic and [...]