PROXIMITY-COMPENSATED BLAZED TRANSMISSION GRATING MANUFACTURE WITH DIRECT-WRITING, ELECTRON-BEAM LITHOGRAPHY

Proximity-compensated, as well as uncompensated, blazed transmission g ratings with periods of 4, 8, and 16 mu m were manufactured with direc t-writing, electron-beam lithography in positive resist. The compensat ed gratings performed better than the uncompensated ones. For the 4-mu m compensated grating the measured diffraction efficiency was 67%. It was 35% for the uncompensated grating. The compensation was made by r epeated convolutions in the spatial domain with the electron-beam poin t spread function. We determined this function by retrieving the phase from the measured diffraction pattern of the uncompensated gratings.