Various techniques for use in spectral narrowing and tuning of excimer laser oscillators are described. Intracavity dispersive elements include Littrow grating, grazing-incidence grating, prisms, and Fabry–Perot etalons. Recent developments to improve overall efficiency and reduce broadband noise are outlined.
Excimer laser micromachining using binary mask projection has been investigated for rapid patterning of single micrometer features over large areas of various substrates. Simple limit for depth of focus that determines the depth to width aspect ratios is given and verified for different materials. Binary mask projection technique is found to conformally reproduce the mask features from the millimetre to the micrometer scale under proper focusing conditions. Large arrays of 1 μm and 15 μm holes on Kapton are made with high resolution and uniform periodicity. Material removal rate (MRR) for the laser machining of these holes are examined and the machining efficiency for these are found to have different dependence on the fluence. A saturation of hole-depth with increasing number of pulses is obtained.
Electrically thick Fabry-Perot omega bianisotropic metasurfaces as virtual antireflective coatings and nonlocal field transformers
