Product Description
Pristine 50mm Diameter Hot Mirror Optical Filter – High-Quality Borofloat Borosilicate Glass with Multilayer Dielectric Coating
Are you building or upgrading an optical system that needs to manage heat effectively? This premium hot mirror is in excellent, like-new condition—pristine. Measuring 50mm in diameter and approximately 3mm thick (standard for this type of filter) , it’s a plano-plano (flat-flat) optic designed for precision applications where thermal management is critical.
Hot mirrors are essential components in projection and illumination systems, where high levels of heat can quickly damage sensitive elements. They are specially coated to transmit visible light while reflecting the near-infrared (NIR) radiation that is a major contributor to heat generation .
Key Specifications
| Specification | Details |
|---|---|
| Diameter | 50 mm |
| Thickness | ~3 mm (typical for 50mm hot mirrors) |
| Shape | Plano-plano (flat-flat) |
| Substrate Material | Borofloat® 33 borosilicate glass (or equivalent) |
| Coating Type | Advanced multilayer dielectric thin-film (dichroic shortpass) |
| Coating Location | One side (marked with edge pointer for orientation) |
| Surface Quality (Coated Side) | Estimated 40-20 scratch-dig (typical for quality optics) |
| Angle of Incidence | Optimized for 0° |
| Visible Transmission | >85% (425-675 nm typical) |
| NIR Reflection | >90% (750-1150 nm typical) |
| Appearance | Distinctive orange/gold reflective color |
| Condition | PRISTINE – no scratches, chips, or coating defects |
Material Advantages
Borofloat® 33 Borosilicate Glass :
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Excellent thermal shock resistance
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Low thermal expansion coefficient
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High dimensional stability under temperature variations
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Superior durability compared to standard glass substrates
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Ideal for heat-intensive optical setups
Multilayer Dielectric Coating :
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Advanced thin-film design for precise spectral performance
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Reflects harmful infrared radiation while transmitting visible light
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More durable than metallic coatings—resistant to scratching and environmental degradation
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No absorption or degradation over time when properly handled
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The distinctive orange/gold appearance confirms proper coating application
Optical Performance
| Wavelength Region | Typical Performance | Function |
|---|---|---|
| Visible (400-700 nm) | >85% Transmission | Preserves image brightness and color fidelity |
| Near-IR (750-1150 nm) | >90% Reflection | Removes heat-generating radiation |
The filter is optimized for 0° angle of incidence but performs well at low angles, providing design flexibility for various optical configurations .
Applications
This versatile hot mirror is ideal for a wide range of optical systems requiring effective thermal management:
Projection and Display Systems:
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Remove IR from halogen or xenon light sources in projectors
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Protect DLP or LCD panels from heat damage
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Enhance color purity by removing unwanted IR
Illumination Systems:
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Fiber-optic illuminators
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Microscope light sources
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Medical and surgical lighting
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Endoscopy illumination
Imaging and Sensing:
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Machine vision systems with high-intensity lighting
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Thermal management in sensor packages
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Colorimetry and spectroscopy setups
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Camera systems requiring IR reduction
Laboratory and Research:
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Optical benchtop experiments
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Photonics prototyping
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Educational demonstrations of dichroic filters
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Custom instrument development
Condition
PRISTINE – EXCELLENT LIKE-NEW CONDITION
NO VISIBLE SCRATCHES, CHIPS, OR COATING DEFECTS
EDGE MARKER INDICATES COATED SIDE
STORED IN PROTECTIVE PACKAGING
READY FOR IMMEDIATE USE
⚠ HANDLING NOTE: This is a precision optical component with a delicate dielectric coating. Handle only by edges with clean gloves. Avoid touching coated surfaces. Store in clean, dry environment when not in use.



