Materion Barr Precision Optic & Thin Films – Rare High-Precision Annular Primary Mirror 90mm

This is an exceptional, custom-engineered 90 mm diameter concave front-surface primary mirror with patterned coating originally fabricated by Materion Barr Precision Optics for a US Defense Laboratory Wide Field of View (WFOV) Telescope Assembly – an advanced defense/aerospace sensor development program circa 2011.

Key Specifications

• Material: High-purity fused silica (Corning 7980 equivalent) – renowned for ultra-low thermal expansion, exceptional homogeneity, and broadband optical performance.

• Diameter: 90 mm full substrate (“Clear aperture: 90 mm (annular reflective zone from ~40 mm to 90 mm diameter)”

• Surface Figure: Concave aspheric front, precision polished to λ/20 or better; plano back.

• Focal Length: ~105–115 mm (f/1.2–1.3 relative to full aperture) – fast, compact design with outstanding light-gathering power.

• Thickness: Edge thickness: ~10 mm. Center thickness: ~5 mm

• Edge Finish: Fully polished bevel/chamfer for maximum durability and precision mounting.

• Unique custom patterned Coating: Advanced patterned annular reflective coating (protected enhanced silver or multilayer dielectric for broadband visible/near-IR reflection on outer zone (~40–90 mm diameter) with deliberate central ~40 mm uncoated transmissive zone. Back surface features matching central frosted/ground zone for mounting reference and stray-light control. broadband visible/near-IR reflection

• Special Features: Innovative annular pupil design optimizes point spread function (sharper central peak, reduced diffraction sidelobes) – ideal for high-contrast imaging, faint object detection, or multi-path optical systems.

Uses and Applications This unique optic was designed as the primary mirror in a sophisticated Wide Field of View telescope system for high-performance sensing. Its fast f-ratio and annular patterned

coating make it exceptionally suited for applications requiring excellent light collection, wide angular coverage, and superior image quality:

• Astronomy (Amateur & Professional): Ideal as an ultra-fast primary for compact Newtonian, Ritchey-Chrétien, or custom wide-field telescopes – perfect for deep-sky imaging, asteroid tracking, or satellite observation with minimal coma and outstanding contrast on faint objects.

• Space Situational Awareness / Surveillance: Matches original defense use – excellent for ground-based tracking systems, debris monitoring, or low-Earth orbit observation setups.

• Laser Systems: Superb for beam collimation, expansion, or focusing in high-power visible/near-IR lasers; the annular design reduces central intensity for safer beam profiling.

• Scientific Research & Education: Valuable in university optics labs for wavefront sensing, interferometry demonstrations, adaptive optics testing, or hybrid reflective/transmissive experiments (central zone allows simultaneous transmission path).

• Machine Vision / Remote Sensing: High-precision imaging in drones, robotics, or environmental monitoring where wide field and low stray light are critical.

• Custom Sensor Prototyping: The transmissive central zone enables innovative dual-path designs (e.g., combining reflected wide-field imaging with transmitted narrow-field or guidance beam).

This is a rare surplus/engineering unit from a prestigious restricted program. Absolutely pristine and ready for immediate integration or collection.