Diamond diffractive optical elements for infrared laser beam control

Abstract

Recently a new technique has been proposed for laser-assisted generation of phase microrelief to manufacture diamond diffractive lenses for the far IR range. In the present paper the realization of diamond diffractive optical elements (DOEs) is considered, able to focus an incoming CO 2 laser beam into certain pregiven focal domains. Exemplarily, two completely different DOEs for different tasks of laser beam focusing have been designed by different methods, manufactured and finally investigated by means of optical experiment and computer simulation. Measured intensity distributions in the DOEs' focal planes as well as measured diffraction efficiencies have been compared with related results of computer simulation, and have been found to be in good mutual concordance. Obtained first results indicate that technique of laser-assisted ablation can be effectively used for manufacturing of high quality diamond DOEs for laser beam focusing.

Formation of diffractive microrelief on diamond film surface

“…However, the technology described in [3][4][5][6] does not allow the microrelief to be generated with a feature size less than 10-20 mm, which certainly decreases the potential fields of the technology application.…”

“…As an alternative, the use of DFs as substrates of diffractive optical elements (DOEs) was proposed, with their phase relief being generated by selective-area laser etching [3][4][5][6]. The efficiency of this approach was recently demonstrated by the fabrication of anti-reflecting periodic microstructures on a DF surface [7,8].…”

“…In [5,6], the manufactured DOEs to focus the CO 2 laser light were studied experimentally and the results were discussed. However, the technology described in [3][4][5][6] does not allow the microrelief to be generated with a feature size less than 10-20 mm, which certainly decreases the potential fields of the technology application.…”