front surface plano mirror witness sample defense lab MIL-STD-1246

Product Description

High-Quality 1.5″ Front Surface Plano Mirror Witness Sample – Ex-U.S. Defense Optics Lab Surplus

This premium front surface plano mirror witness sample (Part # LL# 71-800940-WS) originates from a premier U.S. defense research laboratory surplus, renowned for advanced optics in national security and space applications. Measuring 1.5 inches (38.1 mm) in diameter and 9.5 mm thick, this robust optical component features a high-precision flat (plano) design with exceptional surface quality, ideal for demanding environments. It is Level 1 certified under MIL-STD-1246 for ultra-low contamination, ensuring suitability for contamination-critical applications such as space instrumentation and high-power laser systems.

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Key Specifications

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Material & Coating Advantages

UV-Grade Fused Silica Substrate:

• Ultra-low thermal expansion (0.55 x 10⁻⁶/°C) for dimensional stability across temperature extremes

• High purity (>99.9%) minimizes absorption and scatter

• Excellent transmission from 200 nm through 2.5 µm

• Superior mechanical strength and chemical durability

• Ideal for vacuum and high-power applications without distortion or outgassing

Protected Aluminum with Dielectric Overcoat:

• 95% average reflectivity across 400-1100 nm (visible to near-IR)

• Dielectric overcoat provides exceptional durability against scratches, oxidation, and environmental factors

• Enhanced lifetime compared to bare or standard protected aluminum coatings

• Suitable for frequent handling, cleaning, and extended field use

• Maintains performance under vacuum and thermal cycling

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Quality Highlights – Defense Grade vs. Commercial

Built to rigorous standards typical of top-tier defense labs, this witness sample exceeds commercial specifications by a significant margin:

This witness sample was likely used for coating qualification in prototype runs for classified or sensitive programs. Its exceptional thickness and finish ensure wavefront accuracy and minimal scatter—perfect for mission-critical optics.

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Why MIL-STD-1246 Level 1 Matters

MIL-STD-1246 defines cleanliness levels for aerospace and defense hardware. Level 1 certification represents the highest cleanliness standard:

This certification is critical for:

• Vacuum and space environments: Outgassing or particle migration cannot be tolerated

• High-power laser systems: Contamination creates absorption sites leading to thermal lensing or damage

• Precision optical assemblies: Scatter from particles degrades performance

• Cleanroom integration: Components maintain cleanliness upon receipt

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Applications & Versatility

Optical Manufacturing & Quality Control (Primary Use) :

• Witness sample for verifying thin-film coatings in vacuum deposition chambers

• Track coating runs without disturbing production optics

• Validate layer thickness, adhesion, spectral performance, and environmental durability

• Destructive testing (adhesion, humidity, abrasion) without risking flight optics

Laser Systems:

• Beam steering and folding in defense and industrial lasers

• Prototype laser cavity testing

• High-power laser experiments (fused silica handles high fluence without distortion)

• Alignment references for multi-beam systems

Space & Defense Prototyping:

• Component testing for surveillance satellites and space telescopes

• Adaptive optics systems for atmospheric compensation

• Space instrument qualification and alignment

• Environmental testing (thermal vacuum, vibration) of optical coatings

Photonics & R&D:

• Spectroscopy setups requiring high and uniform reflectivity

• Interferometry reference mirrors

• Optical bench experiments and educational demonstrations

• Detector calibration and sensor testing

Telescope and Imaging Projects:

• Custom Newtonian or Cassegrain telescope designs

• High-resolution imaging systems for amateur astronomers

• Projector and display prototypes

• Beam steering for LIDAR or remote sensing

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Lot Details

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Condition

EXCELLENT
STORED IN ORIGINAL PROTECTIVE CONTAINERS SINCE MANUFACTURE
NO VISIBLE COATING DAMAGE, SCRATCHES, OR DEFECTS
MIL-STD-1246 LEVEL 1 CLEANLINESS MAINTAINED
NEVER USED IN PRODUCTION – WITNESS SAMPLES ONLY
OPTICAL SURFACES PRISTINE