High-Precision Crown Glass Optical Lens for High-Quality Imaging

1. Material & Form

• Core Material: Made from optical crown glass, most commonly N-BK7 (BK7) or B270. This denotes a specific type of low-dispersion, high-transmission silicate glass.

• Form Factor: A perfectly spherical ball lens or hemispherical lens. It is characterized by its diameter, which defines its optical power.

• Finishing: Features a polished, optical-grade surface finish to minimize scattering and subsurface damage.

2. Key Properties

• High Precision Sphericity: Extremely tight tolerance on roundness (e.g., < 1µm deviation) to ensure predictable and uniform refraction.

• Excellent Homogeneity: High material uniformity (low striae) to prevent internal distortion of the wavefront.

• Broadband Transmission: High transmission efficiency across the visible spectrum (approx. 400-700nm) and into the near-infrared (NIR).

• Low Chromatic Aberration: Inherits the low dispersion (high Abbe number) property of crown glass, reducing color fringing.

• Short Focal Length: Provides very short back focal lengths, enabling compact optical designs.

3. Primary Functions

• Collimation & Focusing: Can collimate light from a fiber or focus collimated light to a very small spot. Its function depends on the object/image position relative to its spherical surface.

• Beam Expansion/Reduction: Used in simple 1:1 imaging or to adjust beam diameters.

• Optical Coupling: Frequently used to efficiently couple light between optical fibers, lasers, and detectors.

4. Common Applications

• Fiber Optic Communications: For collimating output from or focusing light into single-mode and multimode fibers.

• Endoscopy & Medical Imaging: As micro-lenses in miniature probes and imaging catheters.

• Laser Systems: For beam manipulation in diode laser modules, barcode scanners, and LiDAR sensors.

• Sensing & Detectors: Used in photodiode assemblies and optical sensor heads to collect and direct light.

• Precision Instrumentation: Integrated into confocal microscopes, interferometers, and other lab equipment.