| Material: | BK7 | Type: | Plano Concave | 
|---|---|---|---|
| Diameter Range: | 4-260mm | Demension Tolerance: | +/-0.1mm | 
| Surface Quality: | 40/20 | Surface Accuracy: | Lambda/4 In 25.4mm | 
| Centration: | 3 Arc Min | Usage: | Optical System | 
| Coating: | Customized | ||
| Highlight: | pcv lens,plano concave mirror | ||
Our N-BK7 Plano-Concave lenses are available uncoated or coated with a variety of multi-layer antireflection coatings. All lenses feature λ/4 surface accuracy and 40-20 scratch-dig surface quality. N-BK7 is an excellent lens material for most visible and NIR applications. It provides great performance at a good value with its high homogeneity, low bubble and inclusion content and straightforward manufacturability.
| Common Specifications | |
| Lens Shape | Plano-Concave | 
| Substrate Material | N-BK7 or H-K9L | 
| Wavelength Range | 350 nm - 2.0 µm | 
| Diameter Tolerance | +0.0/-0.1 mm | 
| Thickness Tolerance | ±0.1 mm | 
| Focal Length Tolerance | ±1% | 
| Design Wavelength | 587.6 nm | 
| Index of Refraction@ 633 nm | 1.515 | 
| Surface Quality | 40-20 Scratch-Dig | 
| Surface Flatness(Plano Side) | λ/2 | 
| Spherical Surface Accuracy (Concave Side) | 3λ/2 | 
| Surface Irregularity(Peak to Valley) | λ/4 | 
| Abbe Number | vd = 64.17 | 
| Centration | <3 arcmin | 
| Clear Aperture | >90% of Diameter | 

