Search found 401 matches

by Din
Tue Nov 03, 2015 1:53 pm
Forum: General Holography
Topic: Edge Lit
Replies: 5
Views: 3501

Re: Edge Lit

John,
This is the best we've got. The biggest challenge is to launch the light through the edge. If you use commercial silver halide, you need to back it with a glass slab and launch into the slab because the plate is fairly thin.
edge-lit1.jpg
edge-lit1.jpg (49.49 KiB) Viewed 3494 times
by Din
Thu Oct 15, 2015 12:32 pm
Forum: DCG
Topic: question about color changes
Replies: 2
Views: 2255

Re: question about color changes

It depends on whether you're shooting H1/H2 or single beam Denisyuks. Even so, there may be many reasons for this colour change Generally, the colour of a reflection hologram is based on the plane separation, angle of recon wrt the reference angle and recon wavelength. There's a formula in Kogelnik ...
by Din
Fri Oct 02, 2015 12:22 pm
Forum: Gallery
Topic: Wedding present
Replies: 2
Views: 6642

Re: Wedding present

Thanks.
by Din
Thu Oct 01, 2015 2:10 pm
Forum: Gallery
Topic: Wedding present
Replies: 2
Views: 6642

Wedding present

Don't do display anymore, but occasionally, I get to play. These are for a wedding present for a friend. They'll have little rubber feet and end up as coasters.
Motorcycles.jpg
Motorcycles.jpg (90.04 KiB) Viewed 6642 times
by Din
Tue Sep 15, 2015 12:48 pm
Forum: General Holography
Topic: making a hologram printer?
Replies: 6
Views: 4393

Re: making a hologram printer?

Gezzer, Yes, that would be a CGH. However, you haven't specified a "reference beam" into the calculation. In this case, you have a "reference beam", that's pretty much on-axis. That is, the reference beam angle is simulated at zero degrees. You need to add the reference beam to g...
by Din
Mon Sep 14, 2015 6:30 pm
Forum: General Holography
Topic: making a hologram printer?
Replies: 6
Views: 4393

Re: making a hologram printer?

For CGH, or Computer Generated Hologram, you actually calculate Fourier terms. Since the far field pattern of any scene is the Fraunhofer diffraction pattern (Note to Petr: Yes, I know you can have Fresnel hologram also! :) ), the fringe pattern recorded on a hologram is the Fraunhogfer diffraction ...
by Din
Mon Sep 14, 2015 5:55 pm
Forum: General Holography
Topic: making a hologram printer?
Replies: 6
Views: 4393

Re: making a hologram printer?

I think you may be confusing several ideas. The problem with phrases like "digital holography" and "computer generated holography" is that these phrases are not precisely defined. Hence, each person has a different concept in mind. Firstly, digital holography, or digital hologram...
by Din
Wed Aug 26, 2015 2:42 pm
Forum: Off Topic
Topic: Zebra Job Opening
Replies: 0
Views: 4323

Zebra Job Opening

Zebra has announced a job opening for a senior optical engineer/technician. It's a full time position in Austin, TX, where Zebra is based. The top of the "Knowledge, Skills and Abilities" section specifically mentions "Passion for holography", so I thought it may interest some on...
by Din
Wed Aug 26, 2015 1:33 pm
Forum: Beginning Holography
Topic: Unwanted fringes
Replies: 14
Views: 7177

Re: Unwanted fringes

Petr, you got your comment in just at the same time as I did! I think we both agree it's object motion
by Din
Wed Aug 26, 2015 1:32 pm
Forum: Beginning Holography
Topic: Unwanted fringes
Replies: 14
Views: 7177

Re: Unwanted fringes

The picture and the video which I attached in the first post depicted only reconstructed hologram (without real guitar and objects behind). So the fringes are recorded on the hologram. The guitar was without excitation during exposure which means that the fringes are parasitic. Checking the vibrati...