90mm aspheric plano-convex lens 100mm focal length

Product Description

Aspheric Plano-Convex Lens – 90 mm Diameter, 100 mm EFL, Precision N-BK7, Uncoated

This large, high-precision aspheric plano-convex singlet lens was removed from surplus equipment that originated in a U.S. defense laboratory. Featuring a subtle aspheric profile on the convex surface for superior aberration correction, it delivers pinpoint focusing and minimal spherical distortion—ideal for demanding applications. It is a premium-grade optic with no chips, digs, coating issues, or defects in the 85 mm clear aperture, in pristine, ready-to-use condition. It delivers exceptional performance and value.

For the best performance with monochromatic light sources, such as lasers, aspheric optics are recommended. Their surfaces deviate from spherical sections, allowing for optimal aberration correction, particularly important for “fast” lenses with small f-numbers .

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Key Specifications

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Optical Performance and Design Advantages

Aspheric Design for Superior Performance
Aspheric lenses are designed to focus light while eliminating spherical aberration, a common flaw in spherical lenses where rays from the edge focus at a different point than rays from the center . This lens’s 100 mm EFL and ~90 mm diameter give it an approximate f-number of f/1.1. Lenses with an f-number below about f/2 are considered “fast” and introduce significant aberrations, making an aspheric design critical for achieving a tight, diffraction-limited spot .

Material: N-BK7
N-BK7 is the most common optical glass for general-purpose precision optics. It offers an excellent combination of high homogeneity, low bubble and inclusion content, and straightforward manufacturability, making it a top choice for transmissive optics from the visible to near-infrared spectrum (350 nm – 2 µm) . The 1-inch center thickness provides exceptional rigidity, ensuring the lens maintains its figure even when mounted in demanding setups.

Application Note for Plano-Convex Lenses:
For optimal performance with collimated light (focusing a parallel beam), the curved surface should face the incoming beam. Conversely, to collimate a point source, the plano side should face the source . This orientation minimizes spherical aberration.

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Applications & Common Uses

The unique combination of a large 90 mm aperture and a fast 100 mm focal length makes this lens extremely versatile:

• High-Intensity Condenser System: Ideal for use as a condenser in projectors, illuminators, microscopes, and machine-vision systems where high light throughput is critical.

• Precision Laser Focusing and Beam Collimation: Excellent for laser diode applications in the visible and near-IR. Its aspheric design provides enhanced performance over spherical equivalents for creating tight, clean focal spots .

• Objective Lens for High-Resolution Optics: Can serve as an objective for custom telescopes, spotting scopes, or beam expanders where aberration control is paramount. It is well-suited for high-resolution imaging, microscopy, and advanced laser systems .

• Custom Optical Prototyping and R&D: An invaluable tool for test benches and breadboards demanding low-distortion imaging.

• Defense and Aerospace Applications: Originally sourced from U.S. military lab equipment, it is well-suited for replicating systems involving range finders, sensor test systems, targeting optics, or high-energy focusing setups .

• Educational and Demonstration Setups: A rare and highly desirable size for teaching advanced optics concepts, offering a large aperture at a fast f/1.1 speed with aspheric correction.

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Condition

PRISTINE – EXCELLENT
OPTICAL SURFACES: Clean, no chips, digs, or coating issues
CLEAR APERTURE: Defect-free
STORED AND HANDLED WITH CARE
READY FOR IMMEDIATE INTEGRATION

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