Relief hologram

It is also possible to digitally record or compute the data required for a diffracting structure and then uses this data to produce relief holograms, usually via a photolithographic process. 

Chomdt M., Leial D., Gregora L, and Srb L, Relief holograms in this films of amorphous As2Se3 under high laser exposures,/. Non-Cryst. Solids, 20, 427-437 (1976). 

Photoresists. These are used in holography because they can be employed to map holographic exposures into surface relief. This property is utilised in the production of embossing masters, reflection and transmission gratings and in computer generated holograms. 

Generally, there are three mechanisms for writing holograms in azo-dye polymers (1) (rotational) molecular reorientation (2) redistribution of cis-and trans-isomer population and (3) formation of surface relief grating. 

The resulting relief-patterned metal surface serves to reflect incident light into a reconstructed image of the hologram. A disadvantage of this approach is the requirement to conduct such metal deposition in a vacuum environment and to mask areas where metal deposition is not desired, especially if the hologram is mounted on a document. 

A holographic polymeric substrate Is formed by casting and curing a polymer precursor in contact with a holographic relief-patterned mold to form a polymeric substrate with a holographic relief-patterned surface. Once cured, the web containing the hologram can be stored or run Into a second print station which applies the catalyst for electroless metal deposition. 

The present article contains data of an exp>erimental recording of relief-phase digital holograms and DOVID on chalcogenide thin films. The obtained holograms can be duplicated by standard modem technologies. 

The effect, whereby the speed with which amorphous As-S-Se films undergo chemical etching, directly depends on the exposure dose, allows for obtaining relief-phase holograms suitable for mass production by conventional technologies and widely used in applied holography. 

There are many materials that can be used for recording holographic interference patterns. Some materials record the pattern as a change in their optical absorption this yields absorption holograms. Other materials record the patterns as changes in their index of refraction or as a relief pattern on their surface these materials produce phase holograms. The thickness of the recording layer is also im-... 

---