Transmission grating efficiencies for wavelengths between 5.4 A and 44.8 A

Area of Science:

• Physics
• Optics
• Materials Science

Background:

• Transmission gratings are crucial optical components in various spectroscopic applications.
• Understanding their diffraction efficiency is essential for optimizing instrument performance, particularly in the soft X-ray and extreme ultraviolet (XUV) regions.

Purpose of the Study:

• To experimentally measure the diffraction efficiencies of a free-standing gold transmission grating for soft X-ray wavelengths.
• To investigate the impact of partial grating transparency on diffraction efficiency.
• To validate a theoretical model for predicting grating performance.

Main Methods:

• Fabrication of a free-standing gold transmission grating with a 1.0-micrometer period.
• Measurement of diffraction efficiencies using characteristic line radiation in the 44.8–5.4 Å wavelength range.
• Comparison of experimental data with model calculations assuming a trapezoidal wire cross section.

Main Results:

• Measured diffraction efficiencies for soft X-rays.
• Observed an increase in efficiency for higher diffraction orders (m≥1) at shorter wavelengths due to partial transparency.
• Model calculations accurately predicted measured efficiencies, enabling determination of the grating's wire cross-section.

Conclusions:

• Free-standing gold transmission gratings exhibit high efficiency for wavelengths as short as 5 Å.
• The gratings are well-suited for applications in X-ray and extreme ultraviolet astronomy.
• The study provides a method for characterizing and optimizing transmission gratings for advanced scientific instruments.