Abstract
The present paper deal with the unique fabrication of Fresnel zone plate(FZP) by laser direct drawing and with the step blazed FZP by glass etching, in addition, its optical characteristics experiment. The FZP is the typical diffractive optical element(DOE), and superior in many characteristics to the other elements such as refractive lenses or reflective mirrors. There are several means to fabricate the FZP, direct laser drawing is used for convenience. The computer generated holography(CGH) method is used efficiently for the pattern generation.The FZP composed of photo resist thin film is fabricated by laser direct drawing and 2, 3 and 4 level step blazed FZP is fabricated by repetition of direct drawing and glass etching. Diffraction efficiency and focusing characteristics are evaluated for various groove depth. In relation to diffraction efficiency, 89 to 97% of theoretical value is achieved, and the maximum efficiency is proved to arise at reasonable depth of the groove.The FZP fabricated is able to focus the laser beam to the theoretical limit.
