Search found 440 matches

by BobH
Sun Mar 10, 2024 9:30 am
Forum: General Holography
Topic: One-step real-image reflection hologram?
Replies: 4
Views: 259

Re: One-step real-image reflection hologram?

One needs a large diameter, short focus lens to do it with reasonable field of view. And the setup will involve more than a single beam. This type was included in the holograms I made when I was a student at Vincennes University in 1980. When done in transmission mode, the image is achromatic.
by BobH
Fri Mar 01, 2024 9:19 am
Forum: Events, announcements, and news
Topic: ISDH 2024
Replies: 1
Views: 924

Re: ISDH 2024

I'm planning on going and encourage as many others to as well. Great opportunity to geek-out over holography for a couple of days. How often does one get a chance to do that in a lifetime? Without all the formalities of a scientific conference. More of a "show & share", swap meet, meet...
by BobH
Fri Jan 26, 2024 8:56 am
Forum: For Sale / Want to Buy / Trade
Topic: Manual for the Coherent Sapphire 532-300
Replies: 7
Views: 1063

Re: Manual for the Coherent Sapphire 532-300

A collimated beam has a divergence. It's 0.
by BobH
Mon Jan 22, 2024 9:07 am
Forum: For Sale / Want to Buy / Trade
Topic: Donate and Help Conservation Research?
Replies: 14
Views: 2232

Re: Donate and Help Conservation Research?

Please contact me directly at the address below. I have plates like you describe that I can send to you that are from 1965, and experience with holograms from the 1960s. I'm also very curious about the hologram you have. Also, please visit my site also mentioned below. laserhistorymuseum.com bob@las...
by BobH
Tue Jan 16, 2024 10:35 am
Forum: For Sale / Want to Buy / Trade
Topic: Looking for photopolymer films
Replies: 11
Views: 10635

Re: Looking for photopolymer films

1. Yes. 2. No. 3. The cover sheet is removed, and the material mounted to a glass plate by pressing the photopolymer side (which is sticky like a post-it note) to the glass. Particles on the glass will cause bubbles, so this needs to be done in a very clean area. 4. Only a UV post cure, which can be...
by BobH
Sat Nov 25, 2023 10:57 am
Forum: Off Topic
Topic: Whatever Became of Holography?
Replies: 19
Views: 21731

Re: Whatever Became of Holography?

Essentially it says to disregard the boundary going from air to emulsion containing fringes. Assume the whole world is the index of the emulsion, and apply coupling theory to the fringes themselves during replay. I'll try and make this simple enough that even you may understand it. Light has to go ...
by BobH
Sat Nov 25, 2023 9:26 am
Forum: Off Topic
Topic: Whatever Became of Holography?
Replies: 19
Views: 21731

Re: Whatever Became of Holography?

If anyone else posts here wanting to see the section, I'll send it to them for comment. I don't think anyone else is interested. Essentially it says to disregard the boundary going from air to emulsion containing fringes. Assume the whole world is the index of the emulsion, and apply coupling theory...
by BobH
Fri Nov 24, 2023 3:26 pm
Forum: Off Topic
Topic: Whatever Became of Holography?
Replies: 19
Views: 21731

Re: Whatever Became of Holography?

... so the various parameters relevant to the efficiency of an edge lit hologram have not as yet been specified (unless you have a reference for such a mathematical reference). I provided the reference above. You just don't want to acquire it on your own. And I don't want to scan it for you, only t...
by BobH
Fri Nov 24, 2023 1:35 pm
Forum: Off Topic
Topic: Whatever Became of Holography?
Replies: 19
Views: 21731

Re: Whatever Became of Holography?

Din wrote: Fri Nov 24, 2023 1:18 pm Then quote those equations.
How about you get the book?

"Also, interpret those equations."

How about you make an edge-lit grating and see for yourself?
by BobH
Fri Nov 24, 2023 11:57 am
Forum: Off Topic
Topic: Whatever Became of Holography?
Replies: 19
Views: 21731

Re: Whatever Became of Holography?

Din wrote: Fri Nov 24, 2023 10:16 am
There is no section 2.6 in the Kogelnik paper. Perhaps if your author could give the relevant equations.
The author gives the relevant equations in section 2.6 of his book.