Micro devices output powerful lasers at room temperature, reducing power consumption by 7 times

Recently, researchers at the Rensselaer Polytechnic Institute in the United States have invented a miniature device thinner than human hair, which can help scientists explore the essence 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 without the need for complex infrastructure.

The researchers stated that "material selection is the most important, and we were the first to choose exciton material CsPbCl3 for this application." CsPbCl3 is a perovskite material that researchers use to manufacture photonic topological insulators (PTIs).

Although classical physics helps us understand the world, technological progress can be attributed to quantum mechanics. The understanding of quantum mechanics, from light-emitting diodes (LEDs) to lasers, transistors, and even electron microscopes, has driven the leapfrog development of modern technology.

However, there are still many unknowns waiting to be explored in the quantum field. Global researchers are using cutting-edge equipment to study the behavior of atomic particles, in order to further enhance their understanding. Meanwhile, Wei Bao, assistant professor of Materials Science and Engineering at RPI, and his team have adopted a unique research path.

What is a photonic topological insulator?
PTI is a material that can guide photons in light to specially designed interfaces inside the material, while also preventing light from scattering through it. This characteristic enables multiple photons within the material to maintain coherence and exhibit the behavior of a single photon.

RPI researchers have utilized this characteristic of materials to transform insulators into a simulated material, creating a miniature laboratory for studying the quantum properties of photons.

In the process of equipment manufacturing, researchers adopted technologies similar to those used in microchip manufacturing. They stack different materials layer by layer, and each molecule is carefully arranged to construct a structure with specific properties.

Firstly, the research team utilized cesium, lead, and chlorine to manufacture ultra-thin perovskite plates. Next, they etched specific patterns on a polymer. Then, the crystal plate and polymer are sandwiched between thin sheets of different oxide materials, resulting in a micro device with a thickness of about 2 microns, a length of 100 microns, and a diameter smaller than that of ordinary human hair.

How does this device work?
When the research team used lasers on the device, a glowing triangular pattern appeared on the material interface. This mode originates from the topological characteristics of the laser and is determined by the device design.

The significant advantage of this device lies in its ability to operate at room temperature. CsPbCl3 has a stable exciton binding energy of up to 64 meV, far exceeding the thermal fluctuation of 25.8 meV at room temperature.

The research team stated in a statement, "In the past, researchers could only supercool substances in vacuum, which required large and expensive equipment. However, many laboratories do not have such conditions. Therefore, our equipment will allow more researchers to conduct basic physics research in the laboratory."

In addition, the device also helps to develop lasers that require lower energy for operation. The threshold of our strongly coupled topologically polarized laser at room temperature (15.2 μ J cm-2) is much lower than the threshold of the low-temperature III-V InGaAs weakly coupled system (~106 μ J cm-2), which is approximately 7 times lower.

Source: OFweek