|  | 
| Design Wavelength | 980 nm | Magnification | 2 | 
| Numerical Aperture | 0.52/0.26 | Window Thickness | 1.517 mm | 
| Clear Aperture | Laser Window Material / Index | N-BK7 | |
| Effective Focal Length | 2.76 mm | Glass | D-ZLAF52LA | 
| Working Distance | Surface Quality | 40-20 Scratch-Dig(Entire Bulk Material) | 
| 355440-C |  |  |  |  |  |  |  | 
| C440TMD-C |  |  |  |  |  |  |  | 
|  | 
| Vd number | 40.73 | 
|---|---|
| CTE (10-6 / °C) | 6.9 | 
| Thermo optic coefficient (10-6 / °C) (Δn/ΔT) | 6.5 | 
| 
 | 
 | 
 | 
| z | SAG as a Function of Y | A4 | 4th Order Aspheric Coefficient | 
| R | Radius of Curvature | A6 | 6th Order Aspheric Coefficient | 
| k | Conic Constant | A8 | 8th Order Aspheric Coefficient | 
| A2 | 2nd Order Aspheric Coefficient | An | nth Order Aspheric Coefficient | 
