Visualization 3.mp4

The Visualization shows how an Optically Variable Device (OVD) "1D Bird" changes its color on transmission as the sample is rotated. The OVD contains eight zones with the gratings of different periodicities from 3000 to 3500 lines/mm and two perpendicular grating orientations (vertical or horizontal). The OVD size is 25×25 mm. It is recorded in the photoresist frame by frame with the dot-matrix laser interference method and then coated with 40 nm silver layer. The frame size is 200×250 μm. The photos are taken in TM-polarized white light. OVDs are used for the document anti-counterfeiting.