Beam ellipticity compensation by holographic optics

摘要

Ellipticity of optical beams can be compensated by means of diffraction gratings. Holographic gratings are a simple alternative, which is noted for the possibility of recording gratings with curved and non-equidistant grooves. Using spherical wave fronts off-axis diffractive imaging elements can be recorded. They can be used for a beam transformation. The usual transformation task is to collimate beams emitted by edge-emitting diode lasers. Holographic recording and reconstruction, taking into account aberrations of the third order and assuming a recording layer to be on a spherical substrate, are described. Experiments verifying theoretical presumptions were carried out. Fraunhofer diffraction pattern with a very narrow central maximum was obtained.