Study reveals that ultrafast laser pulse can be created by gold nanoparticles, according to a study conducted on May 2, 2018.
This study was conducted by the researchers at Aalto University. They have shown that a combination of organic dye material with metallic nanostructures will help in providing ultrafast lasing dynamics with short and rapidly appearing laser pulses.
Researchers wanted to find out the maximum speed at which a laser device can be turned on and off. In the experiments, samples that were made from gold nanoparticles were used. These gold nanoparticles were placed on glass and immersed in an organic, light-emitting material. They are then arranged very close to each other in a square array. Electric fields localized around the particles result in high field strengths that speed up the molecular dynamics in the organic dye.
The electromagnetic fields and the conducting gold particles interacts both with each other and the organic dye for the generation of a directional laser pulse that is ultrafast. This laser will be promising for all-optical switching and sensing and will help in improving the speed of optical telecommunications and performance of devices that requires light to process information.
Päivi Törmä, Academy Professor said, “The key achievement here is that we have succeeded in experimentally demonstrating that the laser pulses are indeed ultrafast. The lasing occurs in optical modes that are hybrids of light and the motion of electrons in metal. These modes are called surface lattice resonances.”
Initially, the metallic nanoparticles squeeze the laser light into sub-wavelength dimensions and then, it escapes from the surface lattice resonance modes as a picosecond-fast, concentrated laser pulse.