Method for calculation and analysis of the weights of grating mosaic errors

Area of Science:

• Optics and Photonics
• Materials Science
• Metrology

Background:

• Fabricating large gratings often involves mosaicking smaller elements.
• Mosaic errors can significantly degrade grating performance.
• Accurate methods for quantifying these errors are crucial for advanced optical systems.

Purpose of the Study:

• To propose a novel method for calculating grating mosaic error weights.
• To present an accurate formula for mosaic error tolerance in large grating fabrication.
• To analyze error weights and tolerances for mosaic echelle gratings.

Main Methods:

• Analytical Hierarchy Process (AHP) for error weight calculation.
• Development of a mosaic error tolerance formula.
• Experimental validation of analytical results for mosaic echelle gratings.

Main Results:

• Analytical error weight and tolerance calculations show good agreement with experimental data.
• The fabricated mosaic grating achieved a far-field intensity of 95.8%.
• This experimental intensity surpasses the simulated value of 94%.

Conclusions:

• The proposed analytical hierarchy process provides an effective method for assessing grating mosaic errors.
• The developed tolerance formula aids in the precise fabrication of large-size mosaic gratings.
• Experimental results validate the analytical model and demonstrate improved performance of mosaic echelle gratings.