Custom Polished Biconvex Lens with AR Coating Options
A biconvex lens, also known as a double convex lens or DCX lens, features two outward-curving surfaces that converge parallel light rays to a focal point, providing precise focusing and image formation. With equal radii on both convex sides, this lens type offers a positive focal length, making it ideal for imaging systems working at near-conjugate distances or for beam convergence in optical assemblies. Designed for both laser and imaging applications, the biconvex lens ensures optimal beam quality, high transmission efficiency, and minimized spherical aberration, supporting reliable performance across laser, imaging, and communication systems.
Key Features
- Double convex design for accurate light convergence—reduces spherical aberration and improves imaging precision.
- Available in a wide range of diameters and focal lengths—ideal for small modules and large optical assemblies.
- High surface quality (20-10 scratch-dig) and <λ/4 surface flatness—ensures stable and consistent optical performance.
- Multiple coating options (UV, VIS, NIR) to suit various spectral applications.
- Custom fabrication available—tailored biconvex lenses and double convex lenses for different wavelengths and environments.
- Supports both prototyping and volume manufacturing with precise alignment control.
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Material Options
Hobbite manufactures biconvex lenses using a wide range of optical materials to meet diverse wavelength and performance needs.
While we specialize in BK7 and Fused Silica for their proven stability and precision, we also process optical crystals such as CaF₂, Sapphire, and UV-grade fused silica for custom projects that require broader spectral transmission or higher durability.
- BK7: A cost-effective, high-transparency optical glass suitable for visible and near-infrared ranges. Excellent for standard laser focusing, imaging optics, and laboratory use.
- Fused Silica: Offers superior UV-to-IR transmission, low thermal expansion, and high laser damage resistance—ideal for UV lasers, fiber coupling, and high-power optical systems.
- Calcium Fluoride (CaF₂): Extends transmission from 350 nm to 7 μm, providing low dispersion and high durability for infrared or broadband optical setups.
All double convex lenses can be coated with advanced AR coatings—including UV-AR, VIS 0°, VIS-NIR, NIR I, or NIR II—to minimize reflection and maximize transmission efficiency across your required wavelength range.
Applications
- Laser Systems: Collimate or focus beams from laser diodes, fiber outputs, or high-power laser modules with minimal energy loss.
- Imaging Devices: Provide sharp, distortion-free images in microscopes, projectors, cameras, and machine vision systems.
- Optical Communication: Efficient light coupling for optical transceivers or fiber systems, suitable for 1310 nm and 1550 nm telecom bands.
- Medical Instruments: Focus therapeutic or diagnostic lasers, ensuring safe and precise energy delivery.
- Illumination Systems: Collimate LED or lamp sources for uniform and high-efficiency lighting in industrial or scientific setups.
- Sensing and Metrology: Enhance beam uniformity and detection range in LIDAR, spectrometers, and optical sensors.
How to Choose (Simple Guide)
Selecting the right biconvex lens ensures your optical system performs at its best:
- Focal Length: Short focal lengths (10–30 mm) give strong focusing for compact laser modules; longer ones (50–200 mm) provide smooth collimation for projection or beam delivery.
- Diameter: Larger lenses collect more light and are used in high-power systems; smaller lenses fit miniaturized optical setups.
- Material Choice: BK7 for visible-to-NIR; Fused Silica or CaF₂ for UV, IR, or thermally demanding environments.
- Coating: Choose AR coatings matching your wavelength range to improve transmission and reduce reflection.
By selecting the right design and coating, your double convex lens will deliver precise focusing, improved image contrast, and long-term reliability in any optical system.
Call to Action
Request a Quote for a custom Double Convex Lens today. Contact Our Optical Engineer for design consultation and system integration support.
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 | Biconvex Lens (BK7 / Fused Silica / CaF₂ options) |
Parameter | BK7 Biconvex Lens | Fused Silica Biconvex 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 |
