Questions about Transmission Gratings

The standard AR coating is for the visible region only. It covers 400 to 750nm and is typically 1.5% reflection.

10.6 microns

  • Soda Lime glass (float): 9×10-6/degreeC
  • Annealed Borosilicate (Pyrex): 3×10-6/degreeC
  • Zerodur: 0.1×10-6/degreeC

The limit is ±0.5% but most gratings are typically much better.

Dispersion required and efficiency at peak wavelength are often trade-offs. Coarse gratings, for example, generally have higher peak efficiency but lower dispersion.

It is the blaze angle of the grating.