Durable BaO–ZnO–P ₂ O ₅ glass with small stress‐induced birefringence for lead‐free polarization light‐controlling devices

Abstract Barium zinc phosphate glasses formulated in the x BaO–(60 − x )ZnO–40P ₂ O ₅ composition line are investigated for their optical, thermal, and chemical characteristics. These as well as small stress‐induced birefringence were found to be governed by the BaO/ZnO substitution. In addition to the characterization of the properties, the phosphate network was qualitatively and quantitatively described in terms of Q ² and Q ¹ ratios by 1D ³¹ P magic angle spinning nuclear magnetic resonance spectroscopy experiments that also showed the presence of Q ⁰ sites. It turns out that the small perturbations of their photoelastic, magnetic, and chemical characteristics made these glasses very good candidates for use in polarization‐controlling optical devices.