We investigate the optical phenomenon responsible for the colored shine that sometimes appears at the surface of ink
layers in the specular direction, often called bronzing or gloss differential. It seems to come from the wavelength-dependent
refractive index of the ink, which induces a wavelength-dependent reflectance of the ink-air interface. Our
experiments on cyan and magenta inkjet inks confirm this theory. Complex refractive indices can be obtained from
measurements of the spectral reflectance and transmittance of a transparency film coated with the ink. We propose a
correction of the classical Clapper-Yule model in order to include the colored gloss in the prediction of the spectral
reflectance of an inked paper. We also explored effects of scattering by the micrometric or nanometric roughness of the
ink surface. The micrometric roughness, easy to model with a geometrical optics model, can predict the spreading of the
colored gloss over a large cone. Electromagnetic models accounting for the effect of the nanometric roughness of the
surface also predict the attenuation of short wavelengths observed under collimated illumination.
We present multiple-powered phase masks to convert a plane wave beam into different shaped beams. With the squared
phase mask, a hollow beam is obtained before the Fourier plane of the converging lens and a highly focused beam is
obtained after the Fourier plane. With the fourth-power phase mask, a crosshair beam with highly focused point in the
center is formed on the Fourier plane, then a beam lattice with strong light spots on the four corners is generated after the
Fourier plane and the beam lattice has different size on different observing distances. With the fifth-power phase mask, a
self-bending beam is generated over long propagation distances.
For the laser spot size, the blazed diffractive grating fabricated with direct laser writing will has a slantwise lateral facet
edge. To evaluate the influence of the slope of the facet edge of blazed diffractive grating, we calculate the diffraction
efficiencies in +1 order and zero order as a function of the angle for the slantwise lateral facet edge with rigorous
coupled wave analysis. As the lateral facet edge is getting more slantwise, the diffraction efficiency in +1 order decrease
more, which degrades the image quality in monochromatic imaging. But the diffraction efficiency in zero order always
keeps very low to assure the application in optical limiting.