Neutral Density Filter
Neutral density filters attenuate, split or combine beams in a range of irradiance ratios with little dependence
|Neutral Density Glass Type||Metallic Coating Type|
|Material||Optical Neutral Density Glass||N-BK7, Fused Silica|
|Typical Size (mm)||Ф25.0, 50.0 x 50.0||Ф25.0 x 2.0, 50.0 x 50.0 x 2.0|
|Size Tolerance (mm)||±0.2|
|Parallelism||3 arc min.|
|Flatness (per 25mm@633nm)||2λ (General), λ/2(High Precision)|
|Surface Quality||80/50 (General), 20/10 (High Precision)|
|Optical Density||0.04, 0.1, 0.2, 0.3, 0.4, 0.5, 0.8, 1.0, 2.0, 3.0, 4.0, etc.||0.1, 0.2, 0.3, 0.5, 0.8, 1.0, 2.0, 3.0, 4.0, etc.|
|Optical Density Tolerance||±5%|
Note for Interference Filter:
(1). Typical diameter is phi 10.0mm, 15.0mm, 20.0mm, 25.4mm, other size at shape of quadrate, triangular,
or other polygonals are available upon request.
(2). Typical size tolerance is ±0.2mm, better precision is available upon request.
(3). Typical parallelism is 3 arc minutes, better parallelism is available upon request
(4). Typical flatness is 2λ, high precision such as λ/2 is available upon request.
(5). Typical surface quality is 80/50, better precision such as 60/40, 40/20, 20/10 is available upon request.
(6). Optical density (D) is defined as the base 10 logarithm of the reciprocal of transmittance (T):
D=log(1/T) or T=10(-D), Besides the typical optical density listed as above, others are available upon request.