Let me not discourage you from trying, however, be aware. What you're trying to do is to read about driving a car, never having driven one, then getting a fast sportscar and driving it on a freeway. So, proceed with caution. I agree with Petr that you should start with Ag., In fact, I think it may behoove you to get the kit from Integraf.
Insofar as making dcg's on concrete floors, we did it at the first PCCG. That may be where read about it. John brought the plates (roughly 2" x 2" or 50mm x 50mm, if memory serves) , Danny brought the laser - a solid state 532, I think - and I brought the model. We literally set it up on the floor with the plate above it and zapped it for about 2 minutes. John then developed it. So, it is possible. But I've been doing dcg holography since the 80's, John had coated quite a few plates and got the technique down, and, while he was processing I was watching to make sure we were optimising the development procedure. So, it was a team effort with a wide knowledge base. Doing it just from written material, I think you'll find that troubleshooting the hologram will be challenging.
But, if I may air my personal philosophy: If you don't throws the dice, you ain't gonna win nuthin'. I made my first hologram without having any clue what "exposure" meant!
So, good luck!
True for HOEs. Not true for display. For display, generally, the exposure is ~ 50 - 70mW. Of course, it's very lambda dependant. Here's the absorption curves for dcg:lobaz wrote:A DCG plate has sensitivity about 2.5x10^5 uJ / cm^2.