Work

Ultrafast laser inscription of mid-infrared waveguides in Pr 3+ -doped sulfide glass

Year: 2026

Type: article

Abstract: We report the femtosecond laser inscription of mid-infrared waveguides in Pr 3+ -doped chalcogenide glasses with composition 90[0.8(GeS 2 ) – 0.2(Ga 2 S 3 )] – 10[CsCl]. These glasses feature low phonon energies, high rare-earth solubility, and broad transparency, although impurity absorption emerges at higher doping levels. Pr 3+ ions in the glass feature broadband luminescence spanning 3.5–5.5 µm. Three hexagonal-cladding waveguides (27 µm diameter) with varying channel separations were fabricated in a longitudinal writing geometry and characterized using μ-Raman and μ-luminescence spectroscopy, Nomarski microscopy, and confocal profilometry. The study revealed densification in the laser-modified regions and an anisotropic stress field surrounding the waveguides. The waveguides exhibited low propagation losses (<1 dB/cm) with no significant additional loss from Pr 3+ doping, highlighting their potential for mid-infrared sensing and integrated photonic devices.

Source: Optical Materials Express

DOI: 10.1364/ome.592158