Lithuanian and Japanese researchers develop silver nanolaser

Recently, researchers from Kaunas University of Technology (KTU) in Lithuania and the Tsukuba National Institute of Materials Science in Ibaraki, Japan, have collaborated to successfully develop a new type of nanolaser based on silver nanocubes.

Although its structure is small and can only be observed through high-power microscopes, its potential application prospects are broad, and the research team is confident in this.

This nanolaser has broad potential applications in early medical diagnosis, data communication, and security technology. At the same time, it is also expected to become an important tool for studying the interaction between light and matter. The amplification and generation of laser light vary depending on the application, determining the color of radiation and the quality of the laser beam.

According to Juod NAS from KTU, a co-author of the invention, "Nanolasers use structures that are one million times smaller than millimeters to generate and amplify light, and their laser radiation is generated in extremely small volumes of materials.

Although research and development of nanolasers have been ongoing for some time, the versions developed by KTU and its Japanese partners have unique manufacturing processes. They used silver nanocubes arranged neatly on the surface and filled with optically active materials to create the mechanisms required for amplifying light and generating laser effects.

As extremely small single crystal silver particles, silver nanocubes possess excellent optical properties and are the core components of our nanolaser, "said Juod NAS, a researcher at KTU Institute of Materials Science.

These nanocubes were synthesized using a unique process invented by KTU partners in Japan, ensuring their precise shape and quality. Subsequently, using nanoparticle self-assembly technology, these cubes were arranged into a two-dimensional structure. During this process, particles naturally arrange from the liquid medium onto the pre designed template.

When the template parameters match the optical properties of the nanocubes, a unique phenomenon called surface lattice resonance occurs, effectively generating light in the optically active medium.

Unlike traditional lasers that generate this phenomenon using mirrors, the KTU team's nanolaser utilizes a surface with nanoparticles. When silver nanocubes are arranged in a periodic pattern, light is captured by them. This process is similar to the mirror hall of an amusement park, but here the mirror is a nanocube and the 'visitor' is light, "Juod NAS metaphorically said.

These captured lights accumulate continuously until they eventually cross the energy threshold of stimulated radiation, producing a strong beam of light with a specific color and direction. The term laser is an abbreviation for stimulated emission of light, which describes this process.

By using high-quality and easily producible silver nanocubes, this laser can operate at record low energy, providing the possibility for large-scale production. Juod NAS pointed out that "chemically synthesized silver nanocubes can be produced in large quantities, and their high quality allows us to use nanoparticle self-assembly technology. Even if the arrangement is not perfect, their properties can compensate for this deficiency.

However, in the early stages of the project, although the simplicity of the method should have been a concern, Lithuanian research funding agencies were skeptical. Some skeptics question whether our simple method can create sufficiently high-quality nanolaser structures, "said Professor Sigitas Tamulevicius from KTU Institute of Materials Science.

Nevertheless, the KTU team firmly believes in the quality of their nanolaser and has successfully secured funding from an international organization. Juod NAS explained, "After extensive work and experimentation, we have demonstrated that using high-quality nanoparticles can achieve effective results even if the array is not perfect.

Source: OFweek