Product Description
Surplus Convex Dielectric Mirror – 63mm Diameter, 2m Radius of Curvature
This precision convex mirror is a high-quality optical component ideal for applications requiring beam divergence or wide-field reflection. The front surface features a multi-layer dielectric coating optimized for high reflectivity in the visible spectrum (approximately 400-700 nm), providing excellent performance in laser optics and experimental setups. The convex curvature (with a gentle 2-meter radius) produces diminished, upright virtual images, making it suitable for use as a diverging mirror in beam expanders, optical testing equipment, or custom imaging systems.
Originally from a laser optics supplier (likely Lumonics or similar), this mirror bears the marking “2MCX,” confirming its 2m radius convex design. The Lumonics heritage connects it to a pioneering company in industrial and scientific laser development, now continued by LightMachinery .
Note: The rear plano side has surface hashes (scratches/markings) that prevent effective use from that orientation, so this is intended for front-side reflection only. The fused silica substrate maintains structural integrity with no impact on the coated convex surface.
Key Specifications
| Specification | Details |
|---|---|
| Diameter | 63 mm |
| Thickness | 9 mm (nominal) |
| Center Sagitta | ~0.25 mm (due to curvature) |
| Radius of Curvature | 2 meters |
| Focal Length (magnitude) | ~1 meter (diverging applications) |
| Substrate Material | Fused silica (quartz) |
| Coating Type | Multi-layer dielectric on convex front surface |
| Coating Wavelength | Visible spectrum (400-700 nm), high reflectivity |
| Marking | “2MCX” (confirms 2m radius convex) |
| Condition | Surplus – excellent optical quality on coated side |
| Rear Side | Unusable due to surface hashes (scratches/markings) |
Material Advantages – Fused Silica
Fused silica is an exceptional substrate material for precision optics, offering:
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Low Thermal Expansion: Coefficient of thermal expansion ~0.50 x 10⁻⁶/K, providing dimensional stability across temperature variations .
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High Thermal Stability: Critical for maintaining optical performance in laser systems and variable environments .
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Excellent Transmission: Suitable for a wide range of wavelengths.
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Mechanical Durability: Resists environmental degradation and maintains figure under stress.
These properties make fused silica the preferred choice for high-performance mirrors in demanding applications .
Applications
Laser Beam Expansion and Divergence:
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Ideal as the diverging element in reflective beam expanders for laser systems
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Reflective expanders offer achromatic performance free from chromatic and spherical aberration, making them ideal for UV, IR, broadband, and ultrafast lasers
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Compatible with a wide range of laser sources including excimer, Nd:YAG, Ti:Sapphire, and tunable lasers
Optical Experiments and Testing:
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Educational labs and university research
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Prototyping optical systems
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Beam profiling and characterization setups
Custom Imaging Systems:
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Wide-field reflection applications
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Low-magnification viewing systems
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Beam steering and control
Telescope and Instrument Integration:
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Secondary mirrors in reflective telescope designs
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Beam conditioning in spectroscopic instruments
The convex mirror design produces diminished, upright virtual images, making it particularly useful for expanding beam diameters and controlling divergence in optical paths .
Condition
SURPLUS – EXCELLENT OPTICAL QUALITY ON COATED SIDE
FRONT SURFACE: Pristine, no visible coating defects
REAR SIDE: Surface hashes (scratches/markings) – unusable for reflection
SUBSTRATE: Structurally sound, no impact on coated surface
MARKING: “2MCX” clearly visible
⚠ USAGE NOTE: This mirror is intended for front-surface reflection only. The rear side has surface markings that preclude effective use from that orientation. This does not affect performance when used as designed.



