Glass Material Options for Optical Prisms: BK7, Fused Silica, and N-SF11 Compared
Glass Material Options for Optical Prisms: BK7, Fused Silica, and N-SF11 Compared Choosing the right substrate for an optical prism is rarely a glamorous decision, but it is often the difference between a system that performs and one that drifts, distorts, or fails under thermal load. Engineers routinely face the same three candidates: BK7 for general-purpose work, fused silica when the environment turns hostile, and N-SF11 when dispersion control is non-negotiable. Each brings a distinct refractive index, Abbe number, and transmission profile to the table. This comparison walks through the material properties, application fit, and practical trade-offs so you can specify with confidence. We will look at what each glass does well, where it struggles, and how to match the substrate to your operating wavelength and thermal budget. Key Takeaways BK7 offers the best cost-to-performance ratio for visible and near-infrared applications down to about 350 nm. Fused silica delivers superio...