The analysis of holographic mosaic gratings' error

摘要

We present a method to analyze mosaic gratings' error in order to make large scale grating. The gratings' rotation condition and phase condition are designed to be controlled by the Moire fringes formed on the reference grating. The orientation and period of the Moire fringes can show the grating's rotation condition, and the phase can express the grating's phase condition. The phase congruence of the Moire fringes and the mosaic gratings is researched when the planes of reference grating and the mosaic grating's substrate are not parallel. In addition mosaic gratings' phase error brought by the drift of optical path difference is presented. And mosaic gratings' errors caused by the movement of workbench during the two exposure are analyzed. Considering all of the errors above the mosaic gratings' error is about 0.15λ. And the value is near the request of mosaic grating which is designed to be used for pulse compressor. Finally the precision of mosaic gratings' error is confirmed by the experiment. The analysis of holographic mosaic gratings' error provides the theoretical support for making large scale gratings.