2 inch fused silica parabolic mirror f/0.625

Product Description

2-Inch Fused Silica Parabolic Mirror – Fast f/0.625 Optic with Protected Aluminum Coating

This is a high-quality 2-inch diameter on-axis parabolic mirror, precision-ground from optical-grade fused silica (synthetic quartz glass) for exceptional thermal stability and broadband performance.

The front surface features a concave parabolic curve, delivering a very fast focal ratio of approximately f/0.625 (focal length ~1.25 inches) . Parabolic mirrors are essential for applications that demand aberration-free focusing, as they eliminate the spherical aberration inherent in spherical mirrors. This is particularly critical for very “fast” systems like this one.

The reflective coating is protected aluminum with a thin SiO₂ hard coat on top. This is an industry-standard coating that ensures durability, resistance to tarnishing, and high reflectivity across visible and near-IR wavelengths (typically >85% average from 400-1100 nm) . The SiO₂ overcoat protects the delicate aluminum layer, making the mirror suitable for handling and cleaning, and resistant to oxidation .

The back surface is polished plano, which minimizes mounting-induced stress and allows for easy, repeatable integration into optical setups.

Substrate Excellence: Fused Silica

The choice of fused silica is a significant advantage. Unlike common substrates like aluminum or N-BK7 glass, fused silica boasts an ultra-low coefficient of thermal expansion (0.50 x 10⁻⁶ /°C) . This makes the mirror exceptionally stable in environments with fluctuating temperatures. Its low steady-state distortion coefficient ensures the optical figure is maintained even under thermal load, a critical feature for laser applications . It is also lightweight yet rigid, enhancing portability without sacrificing stability.

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Key Specifications

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Applications & Uses

The combination of a large 2″ aperture and an ultra-fast f/0.625 focal length makes this mirror ideal for applications where maximum light collection in a compact form is paramount.

• Laser Focusing and Collimation: Excellent for creating tight, high-intensity focal spots from larger diameter beams. Its fast f/# is particularly useful for applications like laser-induced breakdown spectroscopy (LIBS) or pumping nonlinear crystals.

• Small Telescope Optics: Can serve as a very fast primary mirror for a compact Newtonian telescope, offering exceptional light-gathering power for deep-sky observations.

• Solar Concentration: Perfect for DIY solar experiments or concentrators, where focusing intense sunlight to a small point is required.

• Custom Optical Experiments: A valuable tool for R&D breadboards, test benches, and educational setups needing a high-NA reflective element.

• Illumination Systems: Can be used as a condenser to collect and focus light from a divergent source (like an LED or arc lamp).

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Condition Note

The mirror is in good optical condition and is ready for immediate use in hobbyist, educational, or research projects.

• Front Reflective Surface: Shows some insignificant micron-sized spider-type scratch marks. These are purely cosmetic and do not significantly impact optical performance for most applications.

• Edges: There are minor chips around the edge of the substrate. This is common with surplus optics and does not affect the clear aperture or optical figure.

• Core Optic: The central, optically functional area of the mirror is intact and performs as specified.