Our BK7 bi-concave lenses are precision-engineered to diverge parallel rays and provide a virtual focus on the object side. Ideal for systems requiring negative focal lengths, these lenses are well-suited for applications where conjugate ratios are close to 1:1.

Key Features:

• Material: BK7 grade A, fine annealed for high optical clarity and durability.
• Focal Length: ±2% accuracy at 587.6nm, ensuring precise optical performance.
• Diameter Tolerance: +0.0/-0.20mm for consistent sizing.
• Center Thickness: ±0.1mm, ensuring uniformity in optical performance.
• Centration: 3′ to maintain accurate alignment in optical systems.
• Form Error: 1-5 fringes, indicating minimal surface imperfections.
• Irregularity of Fringes: 0.2-0.5 fringes for high optical quality.
• Surface Quality: 60-40 scratch-dig, meeting standard optical requirements.
• Coating: 1/4 wave MgF2 coating at 550nm for optimal performance at 0° angle of incidence.
• Clear Aperture: 90% diameter, maximizing light transmission.

Applications:

• Optical Systems: Perfect for applications requiring divergence of parallel rays and a virtual focus.
• Conjugate Ratio Applications: Ideal for systems with absolute conjugate ratios close to 1:1.

Contact Us:
For more information or to place an order, please contact us. Our bi-concave lenses offer high precision and quality, tailored to meet your specific optical needs.