First color -ok im hooked on color now

DJ Mathson · Post by **DJ Mathson** » Fri Oct 10, 2008 10:27 pm

I have one of those lasers. I bought it a few years ago because PowerTechnology first said it would work for holography albeit not optimal. Later they said instead that it isn´t suitable after all. The TEC is supposed to control the temp to 0.1 degree. They said that I shouldn´t expect a coherence length longer than 3 mm, and that the IQ1C model is a better choise since it has a better TEC.

I believe MichaelH tested the PPM several times and never got a hologram from it. Therefore I have never tested this laser. Now I need to try out mine also. I believe that if you have a stable environment and find a mode hop free region you can get a long coherence length. But according to the above, I wouldn´t trust this laser for continuous work.

Danny Bee · Post by **Danny Bee** » Fri Oct 10, 2008 11:13 pm

DJ Mathson wrote:I have one of those lasers. I bought it a few years ago because PowerTechnology first said it would work for holography albeit not optimal. Later they said instead that it isn´t suitable after all. The TEC is supposed to control the temp to 0.1 degree. They said that I shouldn´t expect a coherence length longer than 3 mm, and that the IQ1C model is a better choise since it has a better TEC.

I believe MichaelH tested the PPM several times and never got a hologram from it. Therefore I have never tested this laser. Now I need to try out mine also. I believe that if you have a stable environment and find a mode hop free region you can get a long coherence length. But according to the above, I wouldn´t trust this laser for continuous work.

well i have tried it and works fine, dave tested his out and got 12" coherence... so it could depend on the diode installed, both of these modules where reworked by the same guy and hes very sharp guy i know him and he does post here sometimes

DJ Mathson · Post by **DJ Mathson** » Sat Oct 11, 2008 2:25 am

It would be interesting to know what he has done to your PPMs. Regarding the diode, I have a 25 mW 639 nm diode installed in my unit.

dave battin · Post by **dave battin** » Sat Oct 11, 2008 11:40 am

hi guys, the laser Danny is talking about , is a coherent radius laser, its putting out 25mw 0f 635nm. I’ve done a Michelson interferometer test and come up with a total coherent length of @12 inches. im seeing nice solid interference bands (even with laser mounted on table w/tec fan on)..

while the spatial frequency is Tem00, its not as strong as a hene laser. i will try to shoot a grating this weekend and i'll give you an update then.

for a link about this laser please see below.....

http://www.coherentinc.com/downloads/Ra ... 100103.pdf

And also nice work danny!

DJ Mathson · Post by **DJ Mathson** » Sat Oct 11, 2008 12:37 pm

Ok, so it was the Coherent Radius. I thought it sounded strange that the PPM would work. I have seen a few of the Radius on eBay. So they ended up with you two.