Miniature Device Outputs Powerful Laser At Room Temperature, Reduces Power Consumption By 7 Times

Recently, the U.S. Rensselaer Polytechnic Institute (Rensselaer Polytechnic Institute) researchers invented a micro-device thinner than a human hair, which can help scientists to explore the nature of light and matter, and unravel the mysteries of the quantum field. The most important advantage of this technology is that it can work at room temperature and does not require complex infrastructure.
The researchers said, "The choice of material is paramount, and we are the first to choose the excitonic material CsPbCl3 for this application." CsPbCl3 is a chalcogenide material that the researchers used to create photonic topological insulators (PTIs).
While classical physics has helped us understand the world, technological advances owe a lot to quantum mechanics. From light-emitting diodes (LEDs) to lasers, transistors and even electron microscopes, the understanding of quantum mechanics has driven leaps and bounds in modern technology.
However, there are still many unknowns in the quantum realm waiting to be explored. Researchers around the world are using cutting-edge equipment to study the behavior of atomic particles to further their understanding. Wei Bao, an assistant professor in RPI's Department of Materials Science and Engineering, and his team have taken a unique path.
What is a photonic topological insulator?
A PTI is a material that directs photons of light to specially designed interfaces within the material while also preventing light from being scattered through it. This property allows multiple photons within the material to remain coherent and exhibit the behavior of a single photon.
Using this property of the material, RPI researchers turned the insulator into a simulated material to create a miniature laboratory for studying the quantum properties of photons.
During the fabrication of the device, the researchers used techniques similar to those used in microchip fabrication. They stacked different materials layer by layer, with each molecule carefully arranged to build structures with specific properties.
First, the team used cesium, lead and chlorine to create ultra-thin plates of chalcogenide. Next, they etched specific patterns into a polymer. The crystal plate and polymer were then sandwiched between thin sheets of different oxide materials, resulting in a tiny device that is about 2 microns thick, 100 microns long, and less than the diameter of an average human hair.
How does the device work?
When the team used a laser on the device, a pattern of glowing triangles appeared on the material interface. This pattern stems from the topological properties of the laser and is dictated by the design of the device.
A significant advantage of the device is its ability to operate at room temperature.CsPbCl3 has a stable exciton binding energy of up to ~64 meV, well above the thermal fluctuation of 25.8 meV at room temperature.
In the past, researchers could only supercool matter in a vacuum, which requires bulky and expensive equipment," the team said in a statement. But many laboratories are not equipped for this. Therefore, our device will allow more researchers to conduct basic physics research in the lab."
In addition, the device will help develop lasers that require less energy to operate. The threshold of our room-temperature strongly coupled topologically polarized lasers (15.2 μJ cm-2) is much lower than that of the low-temperature III-V InGaAs weakly coupled system (~106 μJ cm-2), which is about a factor of seven lower.