The second grating (G1300) has arrived from Wasatch. Below are pictures of the shadow test we performed. By looking at the zeroth order shadow when the grating is tilted to the blaze peak, we can get a look at the uniformity of the gelatin layer. In the picture below left you can see the dispersed first order light (source is an overhead projector) to the left of the shadow.
02 June 2004:
To the left is a picture of the zeroth order shadow of the G3000 grating seen in the blue light of a projector. By looking at the zeroth order shadow when the grating is tilted to the blaze peak, we can get a look at the uniformity of the gelatin layer. The vertical line near the right side is a reflection from the edge of the substrate.
14 May 2004:
The first of the VPH gratings (G3000) has arrived. We examined the dispersion through the use of a mini-maglite, as well as the fit in the grating holder (bottom right).
28 February 2003:
The VPH grating substrates arrived this week. We unwrapped one of them for inspection. Shown here is one of the substrates (of 15 total - two plus one spare for each grating). This is one of the smallest with a physical size of 200 x 175 x 10 mm. Both sides are polished flat.