dichroic mirror UV fused silica defense lab surplus

Product Description

Premium Research-Grade 3-Inch Dichroic Mirror from US Defense Research Laboratory Surplus – Aerospace-Grade

This large-format dichroic mirror originated as surplus from a US Defense Research Laboratory specializing in advanced photonics, lasers, and sensor technologies. This mirror embodies cutting-edge engineering, pristine condition, custom specifications, and lab-proven performance make it a rare find for optics enthusiasts, researchers, or builders of sophisticated laser systems.

Dichroic mirrors are specialized optical components that have different reflective/transmissive properties at different wavelengths . They are manufactured using advanced thin-film deposition techniques such as ion beam sputtering (IBS) and electron beam deposition, resulting in hard, durable dielectric coatings that withstand high-power lasers and provide exceptional thermal stability .

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Key Specifications

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Substrate & Coating Advantages

UV-Grade Fused Silica Substrate:

• Ultra-low thermal expansion coefficient for dimensional stability across temperature variations

• Impurity-free composition ensures exceptional clarity and minimal absorption

• Excellent transmission from UV through near-IR, down to ~185 nm without absorption or fluorescence

• Ideal for mixed-wavelength setups where standard glass would fail due to UV absorption

• Superior mechanical strength and chemical durability

Front Surface HR Coating (414-488 nm) :

• Dielectric multilayer coating designed for >99.9% reflectivity in the violet to blue spectral band

• Targets key laser lines: 445 nm (InGaN diodes) and 488 nm (argon-ion lasers)

• Vacuum-deposited for superior environmental stability and resistance to laser-induced damage

• Far outperforms metallic coatings in high-power applications

• Selective band allows high transmission outside the reflection range

Back Surface AR Coating:

• Broadband-optimized dielectric coating minimizes back reflections

• <0.5% reflectivity ensures clean transmission of non-reflected wavelengths

• Compatible with UV, visible, and IR wavelengths passing through the substrate

• Maintains signal purity in multi-wavelength systems

Dichroic Performance:
This mirror is designed to separate or combine beams of different wavelengths—reflective below a cut-on wavelength (414-488 nm) and transmissive at longer wavelengths . This makes it ideal for applications requiring precise wavelength separation with minimal loss.

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Applications

Laser Systems:

• Perfect as an output coupler or beam combiner in praseodymium-doped (Pr³⁺) UV lasers, where blue pump light (414-488 nm) is reflected for cavity efficiency while generated UV output transmits

• Suited for argon-ion or blue diode laser setups, reflecting the primary beam while passing harmonics or fluorescence

• Beam combining in multi-wavelength laser architectures

Spectroscopy and Photonics Research:

• Fluorescence microscopy: separates excitation light (blue) from emitted signals (UV or longer wavelengths), enhancing signal-to-noise ratios

• Raman spectroscopy: isolates pump beam from weak Raman signals

• Multi-wavelength interferometry: enables precise beam control

Optical Instruments:

• Beam splitters for LIDAR, remote sensing, or defense optics

• Can be used at slight angles (despite 0° optimization) to spatially separate beams without significant performance loss

• Wavelength division multiplexing in communication systems

Custom Experiments:

• DIY photonics projects, such as frequency conversion setups

• Mixed-wavelength experiments requiring clean spectral separation

• High-power laser beam steering where metallic coatings would fail

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Defense Laboratory Heritage

This mirror’s provenance from a US Defense Research Laboratory specializing in advanced photonics, lasers, and sensor technologies adds significant value. These labs pioneer technologies like airborne laser systems and advanced imaging—this optic represents a tangible piece of that cutting-edge research.

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Condition & Packaging

⚠ HANDLING NOTE: This is a precision optical component with delicate dielectric coatings. Handle only by edges with clean gloves. Never touch coated surfaces. Store in clean, dry environment when not in use.