Femtosecond Laser Direct Writing Of Diffraction Gratings For Modifying The Refractive Index Of Intraocular Lenses

To develop a sophisticated, high-precision femtosecond fiber laser platform specifically designed for the refractive index remodeling in intraocular lenses. 

Experiment Research

The platform was developed utilizing a fiber laser, beam expander, among other components. The precision of this experimental setup was evaluated, and a grating was inscribed on the sample surface using optimized femtosecond laser parameters. Comparative analyses of the refractive index of the samples were conducted before and after laser scanning. Furthermore, the samples underwent examination via micro confocal Raman spectroscopy and X-ray photoelectron spectroscopy to investigate the underlying mechanisms of refractive index modification. 

The femtosecond laser experimental platform underwent testing, during which the point spacing and line spacing of the femtosecond laser pulse, as measured using a scanning electron microscope, were determined to be 10.1436±0.1907µm and 20.3167±0.2177µm respectively, which is consistent with the amount of displacement set in the software. A total of ten experimental samples were scanned. Prior to scanning, the refractive index of the samples was measured at 1.5391±0.0004, which decreased to 1.4462±0.0004 following scanning. Raman spectroscopy analysis revealed that no new peaks emerged in the scanned region. XPS spectra suggested increased hydrophilicity in the processed area.

We constructed a high-precision femtosecond laser experimental platform dedicated to IOL refractive index remodeling, and changed the refractive index of the acrylate material under a specific set of femtosecond laser parameters.This objective is accomplished by inscribing diffraction gratings onto the surface of the samples using the femtosecond laser. We utilized a compact and easily maintainable fiber laser as the seed source, allowing us to precisely adjust both the pulse count and the output power of the femtosecond laser. This setup enabled the observation of experimental outcomes across various parameters. It is anticipated that this technology will provide significant benefits for a larger patients.