Holy crap! mirrors on DT40 pros vs CT6215, wow!

[The_Doctor]

Generally that's short for "UV enhanced aluminum"... most mirrors are bad
in the UV and deep blue range...

P.S. So how do you guys think I should pick colors? take a white tube and
prism it? PCAOM? Can I get away with an RGB diode whitelight?

Thanks, UV enhanced seems likely.

Re choosing colours (or anything), choose for actual purpose. A broadband or tunable source is useful for testing what sort of coatings are there, or looking for deficiencies, but the proof of a pudding is in the eating. A chef might know the science of the food, but it takes more than that to make a good chef beat the best mass produced recipes, and the best chefs include many who don't worry much about food science at all..

People set great store on fine analysis, but improving beyond the best current references needs more than science; it's an art. It's the difference between a technician and a toolmaker. I think it's usually enough to know enough science not to make obvious errors or inefficiencies, but after that a bit of creative work goes further than deeper adherence to standards.

One off-topic case of that is something I'm about to raise in a separate thread, something I worked out as seeming like a good idea, but definitely NOT standard. That's using scanner arrangements that are not orthogonal. I worked out that the improvements are such for a given beam width and scan angle, that improvements in speed should be possible by reducing mirror sizes. I don't know why it's not done, or even if the idea is as good as it seems, or not, but I'll deal with that in the thread when I've made a few files ready for it. I only mentioned it cos we're talking about mirrors and angles, and this business of light at various angles would be important to that idea...

[Pangolin]

Hi guys,

Yadda, if you have some time, it might be interesting for you to actually do some experiments with different mirrors and angles and post your results. Although you say "I'm quite positive that at 45 degrees it meets their specifications", I am not so sure... Neither of us can be, without the proper testing. If it meets their specs, then... well, there is no problem and much of this discussion is moot... If it doesn’t meet their specs, I bet they will replace them!

By the way, just before I left the office today, I picked up three sets of 6215s we have here and "looked through" the mirrors as you showed. I can see purple light through them at zero angle (not entirely surprising) -- but not nearly as blue as yours. Also, I picked up a set of DT-40 scanners loaned to me by David Zurcher and... I can see purple through these as well... These mirrors are quite thin, and I suspec they can't hold decent flatness even standing still... Lets see if I can find some time to put them under our ZYGO (interferometer) to check their static flatness.

Regarding "optimized to scan wider", the actual angle subtended by the coil in all Cambridge scanners is the same. Back around 1995, this was something that Bruce Rohr (then President of Cambridge) and I looked into -- changing the angle of subtense -- but that was to try to optimize the scanners for SMALLER angle, not wider. Really the only thing we can call an "optimization for wide scan angle" is the position sensor. The shadow-cast sensor on the 6800 has a tangential error that gets pretty bad at wide angles, but the butterfly sensor on the 6200 series gives a perfectly linear response. But "how wide the scanner can possibly scan" is not really germane to this discussion. Those mirrors, along with that X-Y mount, were made for a 60-degree optical scan angle. The scanner can scan around 100 degrees optical, but you would need different mirrors and a different mount...

Also, Yadda, since most people here probably use solid state lasers, and don't really know what a "high reflector" is, would you please take one out and take a picture for people? Also, just for grins, hold it up to fluorescent light and take a picture "through" it -- just to show people who have never seen this, or tried it, that even mirrors designed to operate at zero angle and high reflectivity, will indeed pass light thought them. Of course, the wavelengths of the light that the mirror was designed to operate will not pass. Still, for people who have never done this, it might be interesting for them to see. And that was my only point about the "high reflector" discussion.

Doc, regarding your idea, does it involve "multiple reflections"? If so, that's been done before, and there are a few patents which mention that technique. It can be employed most successfully in a single-axis scenario and it would be difficult to come up with an arrangement that can do X-Y.

Best regards,

William Benner

[The_Doctor]

Doc, regarding your idea, does it involve "multiple reflections"? If so, that's been done before, and there are a few patents which mention that technique. It can be employed most successfully in a single-axis scenario and it would be difficult to come up with an arrangement that can do X-Y.

Best regards,

William Benner

Can you tell me how I can see those patents? My own idea isn't the same as one doing multiple reflections, it uses no more elements than the standard orthogonal form, and it does proper X/Y scanning, it's just a lot harder to work out precise measurements though probably just as easy to construct a galvo block with final values as it is now, bar a few tricky angles. Mirror surfaces would need optimising for the new angles, but nothing else would, except the addition of a single steering mirror to get the beam path changed to suit the input angle. Lots of systems in confined spaces use a steering mirror to get the beam to the first mirror anyway, so this isn't new.

For now, having worked again on the files tonight, and written up a clear summary, it seems that this thing is entirely patentable, so either it has been, or it should be. Even if I give it away, I want to be sure that I don't see it make someone exclusive income, as I worked a long time on it to make sure it would work well and be easy to do once the precise numbers were worked out.

If anyone in the UK knows how I can get help with patenting without having to spend lots of money and go through pain and difficulty without need, please let me know how. I guess it needs to be checked with US patents too, and elsewhere, but I just need to see what is already patented regarding non-90-degree layouts.

One thing I can safely claim, and state without giving much away to anyone who hasn't worked on the problem before, is that for a 45 degree optical scan angle, for a given beam width, my layout can drop the mass and volume of the first mirror by HALF or more, without making it thinner or changing what it's made of. I'm not talking about small incremental improvements, a halving of mass is a lot of change.

[yaddatrance]

We actually submitted some patent requests, more for curiosity than anything else, I'll let you know how the process goes... I've heard good news stories and some real horror stories...

Bill, I'll clean up enough to take the HR's out this week... I always just
assumed they were only coated for the lines the tubes care about but it'd
be interesting to see if they were actually broadband... I know my
krypton HRs look completely different from the argon's HRs but I
don't remember seeing that much of difference between the krypton
and the whitelight HRs.

[Pangolin]

Hi guys,

@Doc, you can view US Patents online, at www.uspto.gov. You will need to click on the "Patents" section on the left, and then "Search patents" if memory serves... Also, you will need to install a plug-in for your browser to view the patent images. I use "AlternaTIFF". It's free and it works great.

For international patents, you go to www.wipo.org (the World Intellectual Property Organization). Then, on the left click "Patents". Unlike USPTO, you can see the patent images on WIPO with a simple PDF viewer.

I recommend you to the following. First, you can poke around on USPTO and see if you can find any prior art which would destroy the novelty of your invention. My experience has been that USPTO is faster and easier to search than WIPO. If you can't find anything in USPTO, then search WIPO. If you can't find anything there, and your idea seems unique, you can hire an IP attorney and file a "provisional patent application". That will preserve your filing date, and also it involves minimum cost of between $500 and $1000 US. Then you can figure out where to go with your idea after that.

At any point in time (before or after you have filed a provisional application), I would love to see what you have come up with. I would be willing to sign a Non Disclosure / Non Compete agreement, and can advise you on whether I have seen your idea in practice before, and its applicability into various segments (display, making, cutting, etc.). Those who know me know that I am honorable and, as a further testament, everyone who has worked with Pangolin in an IP capacity, at any point in the past, is still working with us today. This is a good indication that we don't "screw" people

@Yadda, as I wrote in a private email -- I just think it would be interesting for the folks here on PL to see an HR. Probably only a handful (if that) know what an HR is, and how it works. Yes, at the rated wavelengths, you won't see any light. But you will see light at other wavelengths... The implied point is, just because you can see light through a mirror, doesn't mean the mirror is "bad"

Best regards,

William Benner

[Coo-mo-d]

Not meaning to bring it back up, but I can understand where Yadda is coming from. The professional side of the industry is really cut-throat, everybodys mouths are sealed from information and theres a lot of shady buisness. I like Yadda and the company I work for have been crooked by some of the long-time goers and well known professionals and you do get the "thats just the way it is" or "its your problem now" attitude off them as soon as a problem arrises. I too had to just take the attitude of juat learning from my own experiance and from what I have heard and aquiring the knowledge on my own or reading enough information that I could gather my own conclusions.

Now I know I am going to get some greif for posting that, but thats how it goes on forums. I used to be part of a few different forums for various things but now tend to stay away since there always seems to be arguing, bashing, patronizing, and assumptions about people and their knowledge or the way they do things. I did join this forum since I do like some of the stuff that is going on here and how everyone is here to help everyone out. Just as Yadda said Bill probably took offence to his post since he works directly with and supports CT.

It reminds me of the boyfriend/girlfriend or wife/husband situations, if you have something to say or on your mind just come out and say it directly instead of doing the dance around it, cuz not everyone picks up on the hints, reading between the lines or underlaying messages. Taking it back to high school, Constructive Critiscism It would be nice if everyone could just take everything for what it is and look upon it with unbiased descisions. Lets just keep this forum clean

Sorry for any grammer and spelling mistakes, been working for over a month non-stop, just got off a tour and slept for 16 hours, I'm still in recovery.

Brian

[Pangolin]

Hi Coo

Well I have a few points.

First, as far as I can tell, it was long ago when the industry was cut-throat. But as far as I can tell, most participants in this industry are quite open now. This is thanks in part to people like L. Michael Roberts, entities like ILDA and (sorry if it seems like a shameful plug but) companies like Pangolin.

L. Michael Roberts, Patrick Murphy (former partner in Pangolin and current ILDA Executive Director) and I have all worked hard to open up this industry, and bring information from closed doors out into the open. This attitude of openness that we all have shared has been much to the chagrin to companies like Laser Media, Image Engineering, and Laser Images who all thrived back in the days when the industry was cut-throat and information was exclusive to them.

If you don't know me, you probably don't know how hard I personally have worked, along with my close colleagues mentioned above, to help bring information out into the open in this industry. I was a co-author in L. Michael Roberts' book "Laser F/X the Lightshow Handbook" (now back in print by the way). Also, on the Pangolin web site, we have over 750 HTML pages -- many of which are general industry information having nothing to do with our software. We wrote the ILDA Terminology Standard and most of the other ILDA Technical Standards that promote openness came to fruition on my watch as Technical Committee Chairman. And in the "what's new at Pangolin" and "internet links" section, you will find information about Photon Lexicon and other forums. What's more, I have authored many articles that bring information out into the open, having nothing to do with Pangolin as a company. Also, for the past two years, Pangolin as a company solely funded all of ILDA's public relations efforts -- to the tune of $5800 per month -- to help promote lasers as a form of entertainment and art. Of all of the PR that has come as a result, only one article mentions (briefly) Pangolin.

With all of that said, if there is an inference that myself or Pangolin is trying to "keep information within" or "protect the big guys", well, you are barking up the wrong tree!!

Second, it seems that the reference to "that's just the way it is" has been grossly misinterpreted. If you read the whole post again, and then again (sorry that you might have to read it three times), you will find that the reference was actually self-deprecating. What I was saying is that -- hey, everybody in the entire world, including individuals and large companies, and including Pangolin, has a bad day every once in a while. Sh*t happens!! THAT'S JUST THE WAY IT IS!!! (If you watch the movie Forest Gump, you will see exactly how sh*t happens, and why THAT'S JUST THE WAY IT IS.) The reference to "that's the way it is" is related to sh*t happening, and how and why sh*t happens. (Gosh, and I thought I was pretty clear in my writing...)

With respect to his original post, it could very well be that Yadda has a bad mirror. Really I don't know that right now, and neither does anybody else. The problem is, Yadda did not provide quality data so that anybody, including himself, can know. Maybe the mirror looks transparent at the zero angle (oh by the way -- an angle the mirror wasn't meant to operate) but in reality, it meets all specifications. I don't know -- and none of us know, because until now, there have been no *quality* testing done -- just a visual inspection which is not very valuable. Basically, you can't hold a mirror up to the light and gather meaningful data. As an illustration of this, I pointed out the behavior of a High Reflector as an example. It turns out, almost nobody on this forum knows what a High Reflector is, so then nobody can really understand the reference...

Anyway, Yadda and I have taken this up in private emails. He will do some more testing and see if the mirror is really bad or not. And likewise, I will do some testing here, but some different testing. In the end, we will all learn from this, which is what we want. In any event, I don't think that reflectivity is the biggest problem facing this indutry or Photon Lexicon members...

By the way, ordinarily when I make a post in response to someone else's post, it is either to support the information, or to add additional information or enlightenment. Unfortunately, Yadda's original post wasn't entirely complete because the test method (looking at something in the light) wasn't really an appropriate test. Also, my post did not countermand his remarks -- I merely requested that he himself do some additional tests to corroborate his own statements. I don’t think that’s unreasonable…

When comments have been made which are incomplete about scanners or another topic I am familiar with, I do feel it is important for you -- the members of Photon Lexicon -- to have the FULL story. Since I have worked closely with many scanner manufacturers in the past, and have scanner related patents myself, I feel that I can bring a more complete picture to the story. (Not only "that" things are done, but "how" they are done and "precisely why" they are done.)

In life I have often observed that it is often easy to look at the work of others and say "hmmm, well that's stupid" without knowing the whole story. And once you know the whole story, you can often see the brilliance involved. If you -- the members of Photon Lexicon -- only had access to the “hmm, well that’s stupid” part of the story, you might not recognize the true brilliance involved, when it exists. And likewise, I have also observed situations where you look at someone else's work and say "hmm, well that's brilliant", but if you know the whole story you can see just how stupid it is... Hopefully, with the multi-faceted talents of Photon Lexicon members, we can all discover when things are “stupid” and when they are “brilliant”…

Best regards,

William Benner

[Banthai]

hi brian and all

I think what you are saying used to be true ....

But recently i have noticed that more and more pros are posting on here and the thread subject matter is getting more technical and detailed and everyone is sharing and helping .... both yadda and bill are what i call profesional laserists and it great they come here to discuss and educate ... ( well it does educate me )

basicaly what im saying is ... "respect" to any profesional who can find the time to post here ...

all the best ... Karl

Edit..
bugger me bill you beat me to by a minute .... hehe

[Coo-mo-d]

Sorry, maybe I should have gone into more detail and better explained myself. As I was sayin everything you write gets picked down to every word and everyones on the defensive side. In no way did I mean to come accross saying ALL and everyone in the industry is like that which seems to be obvious and made no refrence or indication to you or pangolin. Although I don't know you, I have heard of you, the company I work for is actually a Pangolin dealer and I have also worked with L. Michael Roberts in the past (which ended on a bad note).

I guess "thats just the way it is" was a bad way of describing it. A more specific example would be, trying to get a copy of schematics or something made or fixed from a company that is a supplier, with no garantees or price quotes, just ship it out we will fix it and bill you for it, even if you had just purchased it from them and promised it will do what they say. Again I'm not saying all people or companys, just saying it seems to be happening more then it should, especially considering the small market.

I am a pretty easy going guy and can't even remember the last time I actually got mad at something or someone cuz yes, sh*t happens, but nothings worth getting upset over, it happened so you deal with it and make the best of it.

I understand the aspects of the original topic of the posts (the mirrors), but was mainly making a comment on the reactions of both yourself and yadda on the original topic (defensive, offensive, getting personal, etc). You are correct that mirror reflectivity is the least of problems. Your request was not unreasonable, but often in writting, people can read something and get the wrong vibe off of it then originally intended. You thought the thread sounded CT bashing and became defensive for the product which in turn can make people assume things since you have direct affiliations with them (which has happened in the past with certain chinese brand laser suppliers).

This is why I read as much as possible and everyones postings to conclude my own descisions about things. As you said, hearing the full-story from all angles and understanding the reasons behind them.

A co-worker and I were discussing ion laser power supplies, when troubleshooting linear supplies and seeing some strange things they have done, we question why is that there, but there must be a reason. So we were pondering on ideas for a smaller, more reliable efficient switching supply for large frame lasers using todays newer technology with IGBTS. The concept seems simple enough, but when you look at pre-existing switchers ALC, Lexel, or even one of the "newer" supplies like an Aurora-40 thers much more to it and those questionables are there for a reason. You are right you might not see something that somebody else does and its great to hear a different viewpoint.

It is fantastic that more profesional laserists are coming on here and sharing their experiance and technical information. Again, the reason I don't like forums is because of everybody being so defensive against themselves and picking apart every word in an argument. Just respect everyone and their posts and try not to make assumptions. I joined this forum and started posting since there doesn't seem to be all that much of that going on here. Thers a great thing going on here and would only like to see more of it

Being defensive,
Brian

[yaddatrance]

Coo-mo-od is right about sharks still in the water, I've had to rescue an well
established laser company from a really bad one a year ago!

LMR has always done right by me, he's courteous has a good portfolio of inexpensive mounts and shipped out the parts I wanted in a timely fashion, but I also know a couple of people here in LA who refuse to deal with him, one the laser industry would caulk up as a "learning curve" but the other is a professional I respect... but let's please not go looking for skeletons in this field's closet...