Custom aspheric mirrors for precision metal optics

High-performance machined aspheric mirrors for multispectral systems

At Millpond Optics, we specialize in the manufacturing of custom aspheric mirrors designed for demanding industrial, aerospace, and scientific applications. Utilizing ultra-precision single point diamond turning (SPDT), we provide machined optics that deliver precise focusing and superior image quality without the limitations of chromatic aberration.

Aspheric surface geometry

Unlike a spherical surface, which has a constant radius of curvature, an asphere features a radially varying curvature. The sag $z(r)$ of a rotationally symmetric aspheric surface as a function of radial distance $r$ from the optical axis is typically defined by:

$$z(r)=\frac{r^2}{R(1+\sqrt{1–(1+k)\frac{r^2}{R^2}})}+\sum _{i=2}^n{A}_{2i}{r}^{2i}$$

Where:

• $R$ = vertex radius of curvature
• $k$ = conic constant
• $A_{2i}$ = higher-order aspheric coefficients
• $r$ = radial distance from the optical axis

The first term describes a conic section (sphere, paraboloid, hyperboloid, or ellipsoid depending on $k$), while the polynomial terms allow additional shape control for correcting residual aberrations.