ULE Glass

ULE glass (Ultra-Low Expansion glass) is a titania-silicate glass developed for applications requiring near-zero thermal expansion. The key difference between ULE and fused silica lies in their thermal behavior and composition. ULE contains titanium dioxide, which significantly reduces its coefficient of thermal expansion (CTE) to near zero, making it highly stable under temperature fluctuations. In contrast, fused silica is pure SiO₂ with excellent thermal resistance and optical properties but has a higher CTE than ULE, meaning it is more sensitive to temperature-induced dimensional changes.

When choosing between ULE and Zerodur, the decision depends on application requirements. ULE is an amorphous glass, offering excellent homogeneity, no grain boundaries, and superior performance in precision optical systems, especially in aerospace and lithography. Zerodur, on the other hand, is a glass-ceramic with a similarly low CTE but provides higher mechanical strength and better resistance to deformation under load. It is often preferred for large structural components such as telescope mirrors, where stiffness and long-term dimensional stability under gravity are critical.

ULE glass typically has a near-zero CTE, usually in the range of 0 ± 30 ppb/°C, depending on the grade and processing, ensuring outstanding thermal stability.

ULE glass has moderate mechanical strength compared to ceramics or glass-ceramics. While it is sufficient for many precision applications, design considerations are important to avoid mechanical stress concentrations.

Yes, we offer custom ULE glass machining and fabrication services. With advanced CNC capabilities, including 3-axis, 4-axis, and 5-axis machining, we can produce high-precision ULE components tailored to your specifications. Our services cover complex geometries, tight tolerances, and high surface quality requirements for demanding applications in optics, aerospace, and semiconductor industries.