A Polygonal Model to Design and Fabricate Ion-Exchanged Diffraction Gratings

We propose a simple polygonal model to describe the phase profile of ion-exchanged gratings. This model enables the design of these gratings, as well as the characterization of the ion-exchange process itself. Several ion-exchanged gratings were fabricated to validate the model and to characterize the process involved in their fabrication. From this characterization, we show the practical utility of the model by designing and fabricating both a grating that removes the zero order and a three splitter. The performance of these two elements was good, although the first one stood out especially because only 0.5% of the power remained in the zero order after diffraction. This polygonal model could be useful to design more complex diffractive elements.

Automated summary

A simple polygonal model is proposed to describe the phase profile of ion-exchanged gratings, enabling their design and characterization of the ion-exchange process. Experimental validation of the model demonstrated its practical utility in designing gratings that remove zero order and splitters, with good performance achieved. The model could be beneficial for designing more complex diffractive elements in the future.