D-shaped Mirrors
D-Shaped Mirrors
A D-shaped mirror is a precision optical mirror in which one side of a circular mirror is ground flat, forming a “D” profile. This geometry allows the mirror to be positioned closer to an optical axis or adjacent components, making it especially useful in compact optical layouts and beam-splitting configurations.
D-shaped mirrors are widely used in imaging systems, laser optics, and optical instrumentation where space constraints or beam overlap requirements make standard round mirrors impractical. At Avantier, we manufacture custom D-shaped mirrors optimized for specific wavelengths, coatings, and mechanical layouts.
Why Use a D-Shaped Mirror
The primary advantage of a D-shaped mirror is geometric efficiency. The flat edge enables tighter placement near beams, apertures, or other optical elements without clipping or unnecessary obstruction.
In many optical systems, D-shaped mirrors are used when:
Two beams need to pass very close to each other
A mirror must be mounted near the optical axis
System size must be minimized without compromising beam quality
Compared to full circular mirrors, the D-shaped design provides greater flexibility in system integration while maintaining a usable reflective surface.
Typical Manufacturing Parameters
D-shaped mirrors are fabricated from optical glass or fused silica substrates with controlled surface quality and geometry. Representative specifications may include:
Substrate material: optical glass or fused silica
Surface quality: 40/20
Surface flatness: λ/4
Clear aperture: ≥90%
Coating: metallic or dielectric, as specified
Exact dimensions, flat-edge position, and tolerances are defined based on system requirements.
Custom D-Shaped Mirrors at Avantier
At Star-optics, we produce D-shaped mirrors with a wide range of custom options, including substrate selection, coating type, wavelength optimization, and mechanical dimensions. Our team works with customers to ensure the mirror geometry and coating performance match real system constraints, not just nominal specifications.
If you are designing an optical system that requires compact beam routing, precise beam positioning, or custom mirror geometry, our engineers can assist in defining the most suitable D-shaped mirror configuration. Contact us to discuss your application or request a custom quotation.
