Laser Beam Self-Focusing in Silicon at an Absorbed Wavelength by a Vortex Beam in the Same Wavelength.

In this research, we present a novel approach to achieving super-resolution in silicon using the plasma dispersion effect (PDE) that temporarily controls the complex refractive index of matter. By employing a laser vortex pump beam, which is absorbed in the silicon, we can shape the complex refractive index as a gradient index (GRIN) lens, enabling the focusing of a laser probe beam within the material. Our study introduces a single beam at a wavelength of 775 nm for both the pump and the probe beams, offering tunable focusing capabilities and the potential to attain higher spatial resolution. These findings hold significant promise for applications in nanoelectronics and integrated circuit failure analysis, paving the way for advanced semiconductor imaging and analysis techniques.