Computer Generated Gratings with Multiple Phase Levels.

Phase gratings with more than two quantization levels have recently been of interest for making unusual optical components like lenslet arrays or beamsplitters with multiple outputs. Using more than two phase levels can be beneficial, for example, to increase the efficiency of computer generated diffraction gratings used in array generation. In this memorandum, the fabrication of multilevel phase gratings is described. As an experimental result a stepped phase grating with four levels was produced using a quartz substrate.