change laser polarization

Light and its behaviour and properties
a_k
Posts: 190
Joined: Thu Jan 15, 2015 10:52 pm

change laser polarization

Post by a_k »

Correction: The two lasers are described as having equal wavelength, not sure how equal they really are:
http://www.omicron-laser.de/english/las ... diode.html
The diode lasers of the Bluephoton® / Greenphoton® / Redphoton® DualDiode Series are temperature-stabilized lasing diode modules, with two laser diodes of equal wavelength, whose laser beams are united over special co-linear optics. Through this, it is possible to quasi-duplicate the powers of single mode laser diodes available on the market. The only difference to laser diode modules with only one laser diode is that the DualDiode laser diode modules indicate a crossed polarization. All other beam parameters are identical, which means double power with equal quality.
Just found some more details about these lasers, they seem to have a bragg grating integrated in the active region of the LD and also contain wavelength selective elements in the external cavity, resulting in a very narrow linewidth light source with a coherence length of 250m. I have asked Omicron-Laserage for more details.

http://www.omicron-laser.de/files/pm_14 ... nglish.pdf
Joe Farina
Posts: 804
Joined: Wed Jan 07, 2015 2:10 pm

change laser polarization

Post by Joe Farina »

I like the art-deco 1930's look of this laser: a streamlined blue anodized-looking case, and a brass-colored collimating assembly in front. Its odd appearance seems to match its odd performance.

If the long coherence length can be believed, this would be very interesting for testing with DCG. As Ed Wesly suggested, if the laser has two linear polarization states in one beam, a polarizing beamsplitter cube should separate the beams nicely.

If it has enough coherence over the time needed for the exposure (sometimes this point can be vague), then 35mW (one separated beam) should be plenty of power for smaller DCG holograms, since DCG is very sensitive at that wavelength.
a_k
Posts: 190
Joined: Thu Jan 15, 2015 10:52 pm

change laser polarization

Post by a_k »

35mW at 405nm is plenty in any case. You'll get sensitivities around 2mJ/cm2 DCG (2g gelatin / 0.085g Amdi / 16.5ml H20).
marwaj

change laser polarization

Post by marwaj »

I will test this laser in next week.I'm interesting to make only a single beam Denisyuk holograms on DCG and DC-PVA.
It looks that I will be able to do 2 holograms simultaneously when I will use polarized beamspliter cube and 2 half-wave plates to rotate s-polarized beam to p-polarized beam.

in atachment photo of this odd laser..
Attachments
omicron dual diode.jpg
Joe Farina
Posts: 804
Joined: Wed Jan 07, 2015 2:10 pm

change laser polarization

Post by Joe Farina »

a_k wrote:35mW at 405nm is plenty in any case. You'll get sensitivities around 2mJ/cm2 DCG (2g gelatin / 0.085g Amdi / 16.5ml H20).
Yes, I agree.

For inspiration, here is a DCG hologram made by a_k (Ahmet) using a 405nm laser diode (from a thread in the archived forum, I think the topic was "405nm DCG":

http://holoforum.org/oldforum/download/ ... 924ada0c99

Good luck Marcin.
Joe Farina
Posts: 804
Joined: Wed Jan 07, 2015 2:10 pm

change laser polarization

Post by Joe Farina »

This is the thread for "405nm DCG":

http://holoforum.org/oldforum/viewtopic ... 0b1534d83a
Ed Wesly
Posts: 513
Joined: Wed Jan 07, 2015 2:16 pm

change laser polarization

Post by Ed Wesly »

Might not be a bad idea to make an interferometer to see which of these beams can interfere with each other. Even though both emitters are SLM, there is no guarantee that they are both exactly the same wavelength.

It's starting to sound like they use a polarizing beamsplitting cube to combine the beams.
"We're the flowers in the dustbin" Sex Pistols
Post Reply