Multi-Material Plano Concave Lens with Broadband Optical Coating
A Plano Concave Lens features one flat surface and one inward-curving surface, designed to diverge parallel light rays efficiently. This lens allows precise beam expansion, controlled divergence, and reduced spherical aberration, making it an ideal choice for laser, imaging, and sensing systems.
Key Features
- Precise Beam Divergence: Plano-Concave design allows controlled light expansion with minimal aberration.
- Flexible Sizes & Focal Lengths: Diameters range from 4–80 mm; focal lengths from -10 to -200 mm.
- High Surface Quality: 20-10 scratch-dig with < λ/4 surface flatness ensures consistent optical performance.
- Material Versatility: Almost any optical material can be fabricated; BK7 and Fused Silica provide the most mature and reliable results.
- Custom Integration: Coatings, sizes, and lens shapes can be tailored for compact or miniaturized optical systems.
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At Hobbite, we specialize in custom optical solutions for small-scale components. While we can process nearly any optical material, our expertise is strongest with BK7 and Fused Silica, allowing us to achieve high surface quality, minimal wavefront error, and consistent performance for compact optical assemblies.
Material Options & Customization
Hobbite provides Plano Concave Lenses in a variety of optical materials to meet specific requirements:
- BK7: Cost-effective optical glass with high transparency and stability. Perfect for visible-to-NIR applications, laser beam shaping, imaging, and general lab setups.
- Fused Silica (Quartz): Excellent UV-to-IR transmission, low thermal expansion, and high laser damage threshold. Recommended for high-power lasers, fiber coupling in telecom, or harsh thermal environments.
- Other Materials: Custom optical glasses or crystals can be processed for unique wavelength, thermal, or mechanical requirements.
Customizable parameters include:
- Lens diameter, thickness, and focal length for compact or modular systems
- Surface quality, centering, and scratch-dig precision for miniaturized optical modules
- Optional AR coatings for VIS, NIR, or UV ranges
- Special lens geometries for integration into laser modules, fiber optics, or sensor arrays
Applications
- Laser Systems: Expand laser beams from diodes or fiber outputs for uniform energy distribution in compact modules.
- Imaging Devices: Correct beam divergence in microscopes, cameras, and projectors for high-quality imaging.
- Optical Communication: Diverge light for efficient fiber coupling or transceiver integration.
- Medical Instruments: Safely expand laser beams for low- or medium-power medical applications.
- Illumination: Shape LED or lamp light for even coverage in inspection or scientific instruments.
- Sensing Applications: Improve beam uniformity and detection range in IR/UV sensors, LIDAR, and spectrometers.
How to Choose (Simple Guide)
Selecting the right Plano Concave Lens ensures optimal performance:
- Focal Length: Short negative focal lengths (-10 to -30 mm) for compact divergence; long focal lengths (-50 to -200 mm) for gradual beam expansion.
- Diameter: Larger lenses capture more light but require precise mounting; smaller lenses fit miniaturized devices.
- Material & Customization: Any optical material can be processed, but BK7 and Fused Silica are the most reliable for precision and stability.
- Coating: Select AR coatings according to your operating wavelength to maximize transmission and reduce reflection.
Specifications
| Parameter | Specification |
|---|---|
| Material | BK7, Fused Silica, CaF₂, or customer-specified materials |
| Wavelength Range | 185 – 2100 nm |
| Diameter Range | 4 mm – 80 mm |
| Dimension Tolerance | +0.0 / -0.1 mm |
| Center Thickness Tolerance | ±0.05 mm |
| Sag Tolerance | +0.05 mm |
| Clear Aperture | > 85% |
| Focal Length Tolerance | ±1% (High Precision) |
| Surface Figure | λ/4 PV |
| Surface Quality | 20/10 S/D |
| Centration | < 1 arc minute |
| Coating | Custom coatings available upon request |
| Lens Type | Plano Concave (BK7 / Fused Silica / CaF₂ options) |
Parameter | BK7 Plano Concave Lens | Fused Silica Plano Concave Lens |
Diameter (mm) | 4 / 10 / 12.7 / 20 / 25.4 / 80 | 4 / 10 / 12.7 / 20 / 25.4 / 80 |
Effective Focal Length (EFL, mm) | -10 – -200 | -10 – -200 |
Refractive Index (nd) | 1.5168 @ 587.6 nm | 1.4585 @ 587.6 nm |
Transmission Range (nm) | 350 – 2000 | 185 – 2100 |
Surface Quality | 20-10 Scratch-Dig | 20-10 Scratch-Dig |
Surface Flatness (P-V) | < λ/4 @ 632.8 nm | < λ/4 @ 632.8 nm |
Centration Error | ≤3 arcmin | ≤3 arcmin |
Coating Options | Uncoated / VIS AR / NIR AR | Uncoated / UV AR / NIR AR |
Typical Transmission | ≥92% | ≥93% |
Laser Damage Threshold | 3 J/cm² @ 1064 nm | 10 J/cm² @ 1064 nm |
