Part Number

LAD5520

Diameter (mm):

20

Diameter Tolerance (mm):

+0/-0.10

Effective Focal Length EFL (mm):

55

Back Focal Length BFL (mm):

51.57

Substrate:

N-BK7/N-SF5 or equivalent

Surface Quality:

60-40

Power (P-V) @ 632.8nm:

1.5λ

Irregularity (P-V) @ 632.8nm:

<0.5λ

Focal Length Tolerance (%):

±2%

Centering (arcmin):

<3 arc min.

Center Thickness CT (mm):

7.4

Center Thickness Tolerance (mm):

±0.2

Edge Thickness ET (mm):

21.6

Clear Aperture CA (mm):

>= 90% of Diameter

Type:

Achromats 

Bevel: 

Protective bevel as needed