Attachment 1 - Fused Silica Wedged Window for Beam Sampling Requirement.pdf

Fused Silica Wedged Window for Beam Sampling

1) Window material: The wedged window shall be fabricated out of one of the following glasses:

A) Heraeus Infrasil 301 B) Heraeus Infrasil 302;

C) Corning fused silica 7979; inclusion class “0”, and homogeneity class “AA” D) Corning fused silica 7980; inclusion class “0”, and homogeneity class “AA”

2) Window Diameter: 304 millimeters +0 /-3 millimeters

3) Window center thickness: 38 millimeter +/- 3 millimeters

4) Window wedge angle: 3 degrees+/- 0.1 degrees of angle between the two 304 millimeter diameter surfaces of the window

5) Window surface flatness: Both large surfaces of the window shall be polished to a flatness to within 60 nanometers rms over the windows central diameter of 292 millimeters

6) Transmitted wavefront error: Though there is a surface flatness requirement, there is no requirement for the transmitted tilt-removed wavefront error as the wedge is being specified for the quality of its front surface reflection.

7) Surface scratch/dig: 60/40

8) Coating: One surface of the wedge shall be anti-reflection (AR) coated per an approach that yields a coating irradiance damage threshold of greater than 1 kW/cm2. The coating shall reflect less than 0.3% at wavelengths between 1000 nm and 1100 nm.

9) Polishing of the windows edge is not required.

10) Edge chamfer: the edges of the window shall be chamfered to avoid a sharp edge. The edge chamfering shall not extend into the window more than 2 millimeters

11) Edge inscription: The edge of the window shall be inscribed with

a. the material and the measured surface quality (e.g. ‘glass type’221 60 nm rms)

b. An arrow directed toward the anti-reflection coated side of the wedge. The arrow shall be located on the thickest portion of the wedge

c. The vendor part-number of the wedge if applicable

12) Required reports:

a. Interferogram of each wedged window polished surface shall be provided.

b. Anti-reflection coating performance trace from 1000nm to 1100nm

c. Statement certifying the window material