II-VI ZnSe meniscus focusing lens CO2 laser

Product Description

II-VI ZnSe Meniscus Focusing Lens for CO2 Lasers – 1″ Diameter, 1.5″ Focal Length – Pristine Surplus Optic

This high-quality Zinc Selenide (ZnSe) meniscus focusing lens, manufactured by II‑VI Incorporated (now part of Coherent Inc.) , is a premium optical component designed for optimal performance in CO2 laser systems operating at the 10.6 μm wavelength . Proudly made in the USA by a leading American optics innovator, this lens stands out from lower-grade imports, offering superior material purity, precision craftsmanship, and reliability that justify its premium positioning.

With a 1-inch diameter and 2.29 mm edge thickness, it features a convex-concave (meniscus) shape that minimizes spherical aberration, ensuring superior beam quality and efficiency compared to standard plano-convex lenses . The effective focal length is 1.5 inches when oriented with the convex side facing the light source, making it ideal for high-resolution applications requiring a tight focus spot.

Crafted from low-absorption, high-purity ZnSe material, this lens offers exceptional transmission (>99% with AR coatings) and thermal stability, capable of handling laser powers up to several hundred watts without degradation . It’s in pristine condition—no scratches, fingerprints, or signs of use—ensuring like-new performance straight out of the box.

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Key Specifications

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Why Meniscus? Superior Optical Design

Meniscus lenses are generally used as cutting lenses . They have a convex/concave surface by which the relevant aberration – the spherical aberration – is reduced . The achievable focus diameter is smaller than that of plano-convex/plano-concave lenses, particularly at short focal lengths .

For a fast lens like this 1.5″ FL (approximately f/1.5), the meniscus design is critical:

• Minimized Spherical Aberration: All rays are brought to nearly the same focus point, resulting in a smaller, more intense spot .

• Superior Beam Quality: Essential for high-resolution cutting, engraving, and marking applications.

• Improved Efficiency: More energy delivered to the workpiece, reducing waste and improving processing speed.

In many applications, particularly at long focal lengths, plano-convex lenses can be used without a problem. However, the shorter the focal length or the larger the beam diameter, the greater the spherical aberration. Then meniscus lenses are preferred .

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Material Advantages – Laser-Grade Zinc Selenide

Zinc selenide components for CO2 lasers are made exclusively with high quality “laser grade” material that can be used even in the kW range . When coated, these zinc selenide elements have a transmittance of T > 99.4 % at 10.6 µm .

Key properties include:

• Low Absorption: Ultra-low absorption at 10.6 μm minimizes thermal lensing and power loss .

• High Thermal Stability: Resists thermal deformation under high-power operation .

• Visible Transmission: ZnSe transmits in the visible range (appears yellow-orange), enabling easy alignment with visible lasers (e.g., HeNe at 633 nm) . This is atypical of other substrates designed for this region .

• CVD-Grown Purity: Chemical Vapor Deposition (CVD) process ensures high-purity, consistent material .

Important Handling Note: ZnSe is a crystal material and not as strong as glass substrates, so great care should be taken when handling, mounting and cleaning these lenses . Apply uniform pressure when handling/mounting. Tools, including tweezers, should not be used because the substrate easily scratches, cracks, or chips . Latex finger cots and gloves should always be worn when handling and cleaning these lenses to keep from contaminating the substrate or coating .

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Applications

Laser Cutting and Engraving:

• High-detail work on non-metals like acrylic, wood, leather, plastics, textiles, and paper

• Delivers clean edges and fine resolutions in machines from brands like Epilog, Trotec, or Universal Laser Systems

• The 1.5″ focal length enables a small spot size ideal for intricate designs

Material Marking and Etching:

• Ideal for barcode marking, serialization, or decorative engraving on organic materials, ceramics, or anodized metals

Medical and Scientific Applications:

• Used in dermatological lasers, surgical tools, or research setups for tissue ablation, spectroscopy, or infrared imaging

Industrial Processing:

• Enhances efficiency in manufacturing lines for packaging, signage, or prototyping

• CO2 lasers excel in cost-effective, contactless processing

DIY and Upgrades:

• A direct replacement or upgrade for entry-level to mid-range CO2 laser engravers (40W-300W)

• Improves cut quality and reduces material waste compared to standard plano-convex lenses

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Condition

PRISTINE – UNUSED
NO SCRATCHES, FINGERPRINTS, OR SIGNS OF USE
OPTICAL SURFACES: CLEAN, COATINGS INTACT
STORED AND HANDLED WITH CARE
READY FOR IMMEDIATE INTEGRATION

⚠ CRITICAL HANDLING NOTE: ZnSe is a soft, brittle crystal material . Always wear gloves when handling . Handle only by edges. Never use tools or tweezers. Apply uniform pressure when mounting . Clean only with approved optical solvents and lint-free cloths if absolutely necessary.