Sorry for my bad English, I wrote many materials about DCG on Russian on Russian part of our Forum
http://holographyforum.org/phpBB2/viewt ... =22&t=5772
Nonetheless, I consider your hologram very salient for record DCG by short wavelength. I don’t record DCG holograms by 405 nm, but I record by all line of Ar-laser and Cd laser (440 nm).
And I presume some variants for shift the color of image to red.
1. Simplest method – change humidity. You can record holograms under small humidity, near 5% and protect hologram after developing under 60-70%. This method nonstable – DCG don’t like big humidity and for high temperature can be destroy.
2. Use broadband developing. Look to two figures. Fig. 1 show narrow spectrum of holograms.
- narrow spectrum of DCG.jpg (129.66 KiB) Viewed 2935 times
The shift of color is small for this case, only for use isopropanol. But sharp of volume is good.
But combination small exposition and big temperature of development give broadband spectrum of image, Fig 2.
- wide spectrum of DCG.jpg (90.25 KiB) Viewed 2935 times
3. The short length of a wave allows receiving the most broadband display. It is connected by that DCG layer absorb the short wavelength very well see Fig. 3, so hardness of layer is variable and registration of interference pattern have big nonlinearity, see Fig. 4.
- Transmission of DCG PFG-04.jpg (194.68 KiB) Viewed 2935 times
- linear and nonlinear development of DCG.jpg (74.55 KiB) Viewed 2935 times
This nonlinearity applied make shift wavelength to red region and simultaneous make wide “distend” the spectrum of reconstruction of image.
So, need very precisely keep four parameters of develop DCG holograms – exposition, time of development, temperature of development and humidity.