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Forming High Efficiency Holograms

IP.com Disclosure Number: IPCOM000073653D
Original Publication Date: 1971-Jan-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Pennington, KS: AUTHOR [+3]

Abstract

A method for forming a high efficiency phase hologram is described. A significant feature of the method is that the recording is not initially fixed after development; therefore, material is not removed from the gelatin until after the gelatin has been hardened by a dichromate process. This avoids undue shrinkage and, therefore, reduces aberrations and loss in resolution. The method steps are as follows: 1) Stress relieve silver halide emulsions in high humidity atmosphere and dry. 2) Expose to form hologram or record of interest. 3) Preharden in SH-5 or other suitable formaldehyde, etc. solution. 4) Wash. 5) Develop. 6) Wash or Stop and Wash. 7) Bleach in cupric bromide bleach to convert silver record to transparent silver compound.

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Forming High Efficiency Holograms

A method for forming a high efficiency phase hologram is described. A significant feature of the method is that the recording is not initially fixed after development; therefore, material is not removed from the gelatin until after the gelatin has been hardened by a dichromate process. This avoids undue shrinkage and, therefore, reduces aberrations and loss in resolution. The method steps are as follows: 1) Stress relieve silver halide emulsions in high humidity

atmosphere and dry.

2) Expose to form hologram or record of interest.

3) Preharden in SH-5 or other suitable formaldehyde, etc.

solution.

4) Wash.

5) Develop.

6) Wash or Stop and Wash.

7) Bleach in cupric bromide bleach to convert silver record

to transparent silver compound.

8) Immerse in solution of ammonium dichromate e.g. (2%-18%

solution) containing a wetting agent, e.g. Igepal.

9) Dry.

10) Reexpose in blue u.v. e.g. 4880A laser at Bragg angle.

11) Remove dichromate with bisulphite solution.

12) Wash.

13) Fix to remove silver halides from gelatin.

14) Wash.

15) Immerse in IGEPAL* solution (i.e. a wetting agent).

16) Immerse in 100 percent boiling isopropanol for 30 sec-1

min. - Dry rapidly.

Several bleaches can be used in Step (7) including chromic, cupric, ferric, etc. bleaches with convert silver to transparent silver compounds without removing other material such as the undeveloped silver halide present in the emulsion after development. Particularly interesting b...