Precision N-bk7 Optical Glass Bi-convex Lens For Microscopes & Tools

1. Material & Manufacturing

• Optical Substrate: Schott N-BK7 borosilicate glass (standard reference 517642)

• Surface Precision:

  • λ/4 surface accuracy @ 632.8nm

  • 60-40 scratch-dig specification

• Coating Options: Broadband AR (MgF₂ or multilayer) for >99.5% peak transmission

2. Critical Properties

• Optical Performance:

  • >92% transmission (350nm–2.0μm uncoated)

  • Abbe number 64.2 (minimizes chromatic aberration)

• Thermal/Mechanical Stability:

  • CTE: 7.1 × 10⁻⁶/K

  • Knoop hardness: 610 kg/mm²

• Precision Tolerances:

  • Focal length: ±1%

  • Center thickness: ±0.05 mm

  • Centration: < 3 arcminutes

3. Core Functions

• Beam Convergence: Short focal lengths (10–200mm) for high-power focusing

• Aberration Correction: Bi-convex design reduces spherical distortion vs. plano-convex alternatives

• Collimation: Converts point sources to parallel light for illumination systems

• Image Magnification: 2X–20X capability for detailed inspection

4. Professional Applications

• Microscopy Systems:

  • Objective lenses in biological/industrial microscopes

  • Condenser optics for Köhler illumination

• Laser Tools:

  • Focusing lenses for medical lasers (dermatology/surgery)

  • Beam expanders in fiber laser cutters

• Industrial Equipment:

  • Barcode scanner optics

  • Machine vision inspection lenses

• Scientific Instruments:

  • Telescope eyepieces

  • Spectrometer collimators