Theoretical determination of the efficiencies for a conducting grating used in the near ultraviolet

Absolute S- and P-plane polarization efficiencies for high frequency holographic gratings in the VUV

High frequency plane gratings (3500 and 3600 gr/mm) have been holographically ruled and blazed for the VUV spectral region. All gratings were coated with 70 nm Al + 25 nm MgF(2). Absolute unpolarized and S-and P-plane polarization efficiencies have been measured for the first and second orders in the 120- to 450 -nm spectral region at 18.5 and 30 degrees angles of deviation. For deep grooves, anomalous features are more pronounced for the P-plane polarization efficiency than for the S-plane polarization efficiency. Holographic gratings can be tailored to produce high polarization or low polarization in the VUV. For comparison, efficiencies and polarization of the best conventional high frequency gratings were also determined. Measurements show that scattered light is significantly lower for holographic gratings in the VUV when compared with the conventional gratings.

Equivalence of ruled, holographic, and lamellar gratings in constant deviation mountings

By use of simple theoretical considerations on the efficiency dependence of a wide class of commercially available gratings, we obtained an empiric equivalence rule. This rule makes it possible to create equivalence classes of gratings that among themselves show a variety of profiles but have, as long as only two orders are propagating, efficiency curves lying very close to each other. The equivalence rule is visualized by drawing a nomogram. The rule and the grating nomogram serve as a basis for finding new and explaining old properties of ruled, holographic, and lamellar gratings.

Simple selection rules for VUV and XUV diffraction gratings

The bulk of diffraction gratings used in the VUV and XUV regions are used at small angles of incidence and have shallow groove depths. Using rigorous electromagnetic theory, it is shown that such gratings behave in a scalar manner. It is then possible to derive universal efficiency curves from which one can obtain with simple rules the efficiencies of gratings with any metallic surface. The role of standard dielectric overcoatings is investigated and is found to be small. Some comparisons with experiments are given.

Grating efficiency theory as it applies to blazed and holographic gratings

Recently developed rigorous theories have been used to investigate the diffraction efficiency behavior of both blazed and holographic gratings. In order to assist designers of spectrometric systems we have covered a complete range of blaze angles for triangular grooves and modulations for sinusoidal groove shape in first and second orders. Several types of mountings are included together with the role played by finite conductivity of aluminum. Useful classifications of both types of gratings are given, as they apply from the near uv to ir regions. Comparisons showing the close agreement between theory and experiment are presented.

Groove depth determination using a laser for sinusoidal groove gratings

We describe a technique for determining the groove depth of gratings having sinusoidal grooves. Absolute efficiencies measured using a laser are compared with numerical results to give an indication of groove depth.