Characterization of the optical components fabricated by femtosecond pulses in transparent materials

Abstract

We report optical characterization of the different optical components fabricated in transparent materials by bulk refractive index modification or surface ablation by femtosecond pulses. The methods used for characterization of the components with refractive index modification fabricated in fused silica by high repetition rate femtosecond KGW:Yb laser were transmission and diffraction measurements at 532 and 632.8 nm wavelengths, and total integrated scattering (TIS) at 532 mn wavelength. The combined characterization methods were sufficient for modification process optimization and allowed creation of the Bragg gratings with diffraction efficiency in range from 55 to 90% and low scattering losses. The forward and backward TIS measurements of the radial polarization converter showed that forward scattering is more than five times as high as backward scattering. Solar cells with modified surface by femtosecond pulse ablation were investigated by TIS and Volt-Ampere measurements. The current increase is registered with growth of the scattering loses in the solar cells.