Method of manufacturing high efficiency, broad bandwidth, volume holographic elements and solar concentrators for use therewith

DETAILED DESCRIPTION FIG.
1 is a pictorial, schematic representation of the technique of this invention for manufacturing the holographic plate of high efficiency broad bandwidth holographic elements; FIG.
2(a) is a schematic representation of the technique of this invention for manufacturing a high efficiency, broad bandwidth holographic element; FIG.
2(b) is a close-up schematic representation of the relative angles between the diverging beam, collimated beam, and the holographic plate; FIG.
3 is a schematic representation of a holographic solar concentrating system utilizing a holographic element made with the method of this invention; FIG.
4 is a schematic representation of a solar concentrating system utilizing reflecting means; FIG.
5 is a side view of several holographic elements working as tiled pairs as part of a solar concentrating system; DETAILED DESCRIPTION OF THE PREFERRED METHOD AND EMBODIMENTS In order to fully understand the embodiments of this invention, it is first necessary to describe the technique of this invention for producing a holographic element including how to fabricate the holographic plate utilized to produce the holographic element.
In producing the holographic element of this invention, it is first necessary to produce a sensitized gelatin.
This gelatin can be manufactured in a number of conventional ways including the preferred method described below.
Deionized water is combined with chromium aluminum (1%) and Kodak Photoflo in the proportion of 49:1 of deionized water to chromium aluminum.
One drop of Kodak photoflo is added for each 50 mL of deionized water-chromium aluminum solution.
This solution is gradually added to and mixed with holographic grade gelatin (such as Kind & Knox holographic grade gelatin).
14 mL of the deionized water-chromium solution is added for each gram of gelatin.
The deionized water-chromium solution is added to the gel in three doses and allowed to sit for 20 to 30 minutes between each dose.
To sensitize the gelatin add 0.
473 grams of Ammonium Dichromate for every gram of the gelatin and then heat to 40 degrees centigrade