Precision-engineered double convex lens with ultra-tight tolerances for demanding optical applications in imaging, lighting, and laser systems.
Frequently Asked Questions
Why is a ±0.005mm diameter tolerance critical for multi-element systems?
In complex optical assemblies, such as high-resolution imaging objectives, even a slight mechanical tilt or decentration can lead to significant coma and astigmatism. A ±0.005mm tolerance ensures a "press-fit" precision within the lens barrel, eliminating the need for manual alignment (shimming) and ensuring that the optical axis of the DCX lens remains perfectly centered.
How do you maintain focal length consistency within ±1%?
Focal length is a function of both the surface radii and the center thickness (CT). By controlling the Center Thickness to ±0.01mm and utilizing high-precision CNC polishing to maintain radius consistency, we ensure that the effective focal length (EFL) remains stable. This is vital for industrial sensors where consistent magnification is required across thousands of units.
What are the challenges of polishing Double Convex lenses with a small radius (R0.8mm)?
Small radii create steep surface slopes, which are difficult to polish uniformly. We utilize Sub-aperture Polishing and custom-tooled diamond abrasives to ensure that the surface accuracy (N=1~3) and irregularity (ΔN=0.1~0.5) are maintained right up to the clear aperture, preventing "edge roll-off" which can degrade peripheral image quality.
How do you verify the surface irregularity (ΔN) on a symmetric DCX lens?
We use He-Ne Laser Interferometers (such as Zygo) to capture the phase-shift map of both convex surfaces. For a DCX lens, each side is tested individually against a reference sphere. A ΔN value of 0.1 indicates that the local deviation from the ideal spherical shape is less than 1/10 of a fringe, guaranteeing a near-perfect wavefront.
Can you provide "Scratch-Dig 10/5" for high-power laser applications?
Yes. For laser-grade DCX lenses, we offer 10/5 Surface Quality. This extreme level of polishing removes micro-defects that could otherwise act as absorption centers, potentially leading to laser-induced damage (LIDT). This is essential for focusing high-peak-power pulses in industrial laser cutting and medical surgery.
Which substrate should I choose for a DCX lens in a high-temperature environment?
If the system is subject to thermal shock, Sapphire or Fused Silica are the preferred choices. Sapphire offers a high thermal conductivity and a Mohs hardness of 9, while Fused Silica provides a near-zero coefficient of thermal expansion (CTE). For standard visible imaging, BK7 (K9) remains the most cost-effective solution due to its excellent homogeneity and chemical resistance.
Do you offer custom Anti-Reflection (AR) coatings for these high-precision lenses?
Absolutely. We provide custom thin-film deposition based on your target wavelength. Options include V-Coats for single laser lines (R < 0.1%) and Broadband AR (BBAR) for wide-spectrum imaging. Each shipment includes a spectrophotometer curve to verify the coating's performance.
