Laser Ben???

Danny Bee · Post by **Danny Bee** » Thu Apr 15, 2010 2:14 am

Laser Ben is he reliable?... any thought?
I was going to spend money but now I am not so sure if this is wise... any Info on this Guy is he reliable? does he stand by his products?

He sells thing on ebay as scotchtech
his ebay shop is http://shop.ebay.com/scotchtech/m.html? ... SRCHX:SRCH

BobH · Post by **BobH** » Thu Apr 15, 2010 3:55 am

He's a high school student whom I've visited and highly recommend. Very on the ball regarding lasers. Make a fair deal with him, and he'll do his best for you.

dave battin · Post by **dave battin** » Fri Apr 16, 2010 9:16 am

while i haven’t purchased anything from him , he is a very knowledgeable young man and seems to have issues with his packaging.
Bob has been able to visit him ,by passing the need to ship/package any items.

142laser · Post by **142laser** » Tue Apr 20, 2010 6:42 pm

I have bought a few lasers from Ben and any problems that came up were taken care of. Make sure you have the deal clear, option to return and ask him to agree to hold your money until you check out the laser. He seems like an OK guy and is not a deliberate rip off by any means. Make the terms clear and be fair; then demand fairness in return. Phil 142laser

Laser Ben · Post by **Laser Ben** » Thu Apr 22, 2010 6:56 pm

Hey Guys,

I have had some trouble with shipping, mainly on these little 10mW blue lasers. I think I have figured it out now, and the ones that were damaged are being replaced. I do try and pack all my lasers the best I can. I try to describe stuff accurately, and at the same time, I expect to get good money for my equipment.

I try and test everything I get as well as I can, I don't use test equipment that is out of Calibration, or that I am not 100% confident in the accuracy of. If you want me to test something, ask me and if I can I will do it.

I believe Danny Bee asked me a question about the Coherence length on the Coherent Cubes I am selling on eBay right now. I honestly don't know how to test them for holography use, and I really can't answer the question. If anyone can answer it, it would be greatly appreciated.

BobH · Post by **BobH** » Thu Apr 22, 2010 11:27 pm

You can bring them over to my place and I'll set up an interferometer if you want.

142laser · Post by **142laser** » Thu Apr 22, 2010 11:51 pm

Physics is an experimental science.

For those who don't know my day job is Teaching Lab Manager at USF Physics Department in Tampa. I run the Demonstration Facility. So I know some Physics and some lasers (hanging around with Sam helps too). So...you cannot get a useful answer out of Coherent because these lasers were not intended for holography; there is no linewidth spec is there? Set up a Michelson Interferometer (two mirrors and a 50% beamsplitter) and measure the coherence length. If it seems as long or longer than a red HeNe then try to get it on a say 8 GHz FSR scanning interferometer type LSA. Measure the linewidth. Sam has an interferometer and so do I (his also) but "mine" in Tampa is 2GHz FSR...probably too narrow. The TEC stabilized diode laser could be decent but I bet a good long HeNe beats the diode for holography. Long Live HeNe lasers! Amen.

PS I have great HeNe's for about the same money; a batch of used, tested, Sam aligned JDS 1145P's with $300 laser stands included and JDS 1218 lab supplies. $500 each for you guys? Over 20 mW. Or brand new for $800; a $3,300 laser. What about 10-400+ mW SLM green lasers with tens of meters coherence length? What is a Coherent Cube?

dave battin · Post by **dave battin** » Fri Apr 23, 2010 1:22 am

BobH wrote:You can bring them over to my place and I'll set up an interferometer if you want.

Im not even sure i would rely on a michaelson interfrometer, the best test is to do a hologram and see what happens. I have tested coherent radius (red) lasers
showing good stable lines over a good distance of traveing on one leg of the interfrometer, and yet still give banding. I was not impressed with the Coherent Radius diode lasers (violet and red versions) as there MTF was quite lousey, i have asked ben to show an raw beam hitting on paper at 20 feet or so , then a good idea of how clean the beam is. Ben agreed to do this and now its been a few day with no picture...........i would not go near this unit without seeing this first !

Ben if you could allow Bob to shoot a quick test shot ,this would be your best bet........

i also a gree with you Phil 100% ,theres nothing (in red) like a good ol HeNe !

Laser Ben · Post by **Laser Ben** » Fri Apr 23, 2010 3:39 am

Hey Bob,

I would be happy to come bring them over and see what kind of result we get. I'll send you a PM and we can figure out a time that works.

I took some pics today of the Violet, didn't have time to get the red. I have both a red and violet Radius to list next followed by a Sapphire 488-20 with a controller from Phil. There is a Verdi V-5 in the works too, I am fixing it up for Junktronix and he will be listing it when I am done, think 5W of SLM green

At ~16 feet(click to enlarge):

Has anyone tested those blue lasers yet? I spent the entire afternoon going through all 30 of the ones I have working and getting them cataloged. Most of the ones now are low power, but are perfect candidates for diode swap. I had one doing nearly 100mW off the bat with no adjustment! I will be selling them at $60 + $14*mW. If you want one doing 5mW, it would be $135 + shipping, guaranteed to make 5mW, with beam profile and power graph.

dave battin · Post by **dave battin** » Fri Apr 23, 2010 9:28 am

Ben,tlhe spot looks good and hot in the middle ,thanks for posing it !

as far as the 473nm B&W units i have sent one to sam in hopes he will dissect it , Danny and myself have made silver and DCG holograms with it, it looks as if these units have only a few MM of coherents. Though one of my dcg holograms did come out with no banding (magicly) at a couple inches!