Formation and Analysis of Dot-matrix Holograms

Abstract

In the present research we have fabricated and investigated dot-matrix hologram in the photoresist. Using X-Y
motorized translation stage we have covered the substrate with diffractive pixels. Dot-matrix pixels in the photoresist
where formed by laser beam interference lithopgraphy (LIL) employing He-Cd (441.6 nm) laser. A simplified
Diffractive Optically Variable Imaging Device (DOVID) allowing quantative image analysis was formed from the array
of two different orientation difractive pixels. The orientation of the diffraction grating in the single pixel was changed
using rotational motorized stage. The sample was analysed opticaly demonstrating its capabilities of suppression and
addition of the “LT” image and the baground. Diffraction efficiency of single pixels estimated using diffraction stand
and employing three different lasers: He-Ne 632.8 nm, DPSS 532 nm and He-Cd 441.6 nm was performed to
demonstrate efficiency of the simplified dot matrix hologram. The original microrelief of the DOVID formed in the
photoresist could be transferred to the shim for the mass production by thermoembosing or UV imprinting.