F. Nikolajeff et al., Fabrication and simulation of diffractive optical elements with superimposed antireflection subwavelength gratings, APPL OPTICS, 39(26), 2000, pp. 4842-4846
With the aim of reducing surface reflections and increasing the diffraction
efficiency we investigated the superposition of subwavelength phase gratin
gs onto blazed phase gratings. With direct-write electron-beam lithography
bare blazed gratings and blazed gratings carrying subwavelength gratings we
re fabricated and their optical performances compared. For TE polarization
the subwavelength-carrying gratings showed a maximum diffraction efficiency
of 90.6%, whereas the corresponding maximum value for the bare grating was
86.3%. The experiment was simulated with rigorous diffraction theory. (C)
2000 Optical Society of America OCIS code: 220.4000.