Grouchy Hermit Posted February 13, 2011 Posted February 13, 2011 I'm looking to build a co2 laser....not as worried about high power as much as a working unit from easy to find parts....the hardest part to find cheap would be the power supply....I can make this a little less hard by keeping the watts down.....I was wondering if a 10 mm tube 600mm long or even shorter with a good vacuum pump would keep the power demands low and still be a laser? Is there math for this?
dragonstar57 Posted February 13, 2011 Posted February 13, 2011 I'm looking to build a co2 laser....not as worried about high power as much as a working unit from easy to find parts....the hardest part to find cheap would be the power supply....I can make this a little less hard by keeping the watts down.....I was wondering if a 10 mm tube 600mm long or even shorter with a good vacuum pump would keep the power demands low and still be a laser? Is there math for this? do you have experience/training with high powered class IV lasers?
John Cuthber Posted February 13, 2011 Posted February 13, 2011 Grouchy, do you realise that, if you don't have a lot of experience behind you your question is a bit like saying "I'm thinking of learning to drive, does anyone have any handling tips for an F1 race car?"
Grouchy Hermit Posted February 13, 2011 Author Posted February 13, 2011 No real experience in co2 lasers.....have some experience in gases..vacuum..high voltage power supplies.....glass.....cutting diode lasers....the next step seemed to be the co2 laser......very forgiving.....and yes safety is always my first concern...before first light I will have stops and glasses in place. The whole project is for the learning experience and if I had the chance to get in a f1 car I would ask for pointers.....but if I didn't get them I would still go for the ride. If you have safety pointers it would be a good ideal to state them instead of some kind of nanny reply
Xittenn Posted February 14, 2011 Posted February 14, 2011 (edited) [math] f(v)dv = \sqrt{\frac{m}{2 \pi k T}} e^{-\frac{mv^2}{2 k T}}dv [/math] [math] I(v)dv = \sqrt{\frac{mc^2}{2 \pi k T v^2_0}} exp \left \{ -\frac{mc^2}{2kT} \left ( \frac{{v-v_0}}{v_0} \right )^2 \right \}dv [/math] Edited February 15, 2011 by Xittenn
dragonstar57 Posted February 14, 2011 Posted February 14, 2011 (edited) No real experience in co2 lasers.....have some experience in gases..vacuum..high voltage power supplies.....glass.....cutting diode lasers....the next step seemed to be the co2 laser......very forgiving.....and yes safety is always my first concern...before first light I will have stops and glasses in place. The whole project is for the learning experience and if I had the chance to get in a f1 car I would ask for pointers.....but if I didn't get them I would still go for the ride. If you have safety pointers it would be a good ideal to state them instead of some kind of nanny reply I'm sorry i assumed that you had far less experience than that. most people asking about co2 lasers only know what powerlabs.org tells them about it... http://powerlabs.org/laser.htm (might help) Edited February 14, 2011 by dragonstar57
John Cuthber Posted February 14, 2011 Posted February 14, 2011 (edited) No real experience in co2 lasers.....have some experience in gases..vacuum..high voltage power supplies.....glass.....cutting diode lasers....the next step seemed to be the co2 laser......very forgiving.....and yes safety is always my first concern...before first light I will have stops and glasses in place. The whole project is for the learning experience and if I had the chance to get in a f1 car I would ask for pointers.....but if I didn't get them I would still go for the ride. If you have safety pointers it would be a good ideal to state them instead of some kind of nanny reply And, since you do have experience it would have been better to state it rather than provoke a nanny reply. We are clever, but we are not psychic and, as Dragonstar says, we get far too many people who are more likely to get a Darwin award than a Nobel prize. To avoid having to deal with their next- of-kin's lawyers we tend to tell people to walk before they can run. If you don't mention you're a professional sprinter, you should expect to get the same advice. It was your first post; how were we meant to know? Edited February 14, 2011 by John Cuthber
Grouchy Hermit Posted February 15, 2011 Author Posted February 15, 2011 I'm no gifted child or nothing.....with a W.VA high school education .... but I am 45 yr.s old and have been doing this kind of shit instead of watching T.V. most of my life. I forget that most of the people on here are still in high school....But even a scary smart high school kid could teach me a thing or two. I'm sure XITTENN was trying to be a wise ass, but the formula may be what I need if one of you more educated people would explain the variables.
dragonstar57 Posted February 15, 2011 Posted February 15, 2011 (edited) I'm no gifted child or nothing.....with a W.VA high school education .... but I am 45 yr.s old and have been doing this kind of shit instead of watching T.V. most of my life. I forget that most of the people on here are still in high school....But even a scary smart high school kid could teach me a thing or two. I'm sure XITTENN was trying to be a wise ass, but the formula may be what I need if one of you more educated people would explain the variables. the idea was that anyone under a certain level of education would find her answer useless ergo protect the laser kiddies Edited February 15, 2011 by dragonstar57
Xittenn Posted February 15, 2011 Posted February 15, 2011 (edited) Most kiddies can't build a laser I'm not too worried about it. I was also not being a wise ass! :/ I found this through google it is along the same lines baddum ching. I think the most appropriate thing to do first would be to buy a book. The Encyclopedia of Laser Physics and Technology looks good and I like John Wiley & Sons but they tend to cut the fat and just cover the topic no course work as would follow from being an 'Encyclopedia.' I also like Physical Chemistry by Thomas Engel it's what I'm studying for Physical Chemistry at the moment, it is introductory and requires basic knowledge of Calculus and Partial Differentials at most(this is a stretch it's actually rather intensive but not entirely cruel.) My baseline on this is another text from 1996 titled A Physical Chemistry by author cannot remember for the life of me which I studied also. This is a pretty broad topic and if you just want the meat and potatoes and not the actual theory I don't think anybody here is very open to comment as safety and laws are always an issue .... I'm not particularly caring myself but I respect the decisions of the mods and operators. Break down of the above equations is like so: [math] f(v) = \; frequency [/math] [math] m = \; mass [/math] [math] k = \; Boltzmann's \; constant [/math] [math] T = \; temperature [/math] [math] v = \; velocity [/math] [math] c = \; speed \; of \; light [/math] all pretty obvious stuff.... The first equation is a probability distribution and the second applies the first to line broadening of your laser. The idea here is that temperature and mass and all the other nice stuff has an effect on your output and this equation will help you define the properties of your system to achieve the desired output .... There are quite a few other equations that are just as important but this seems to be the most relevant. Fine tuning your system will, as always, require a nice clean power source if you wish to attain a respectable profile and so on and yadda yadda ..... I would say more but I wouldn't know what to say :/ Oh and dv was in the wrong place in the first equation and I fixed that ... I see from a prior post that the text was A Physical Chemistry by Joseph Noggle which was no where near as cool as the one by Engel and Reid ... Edited February 15, 2011 by Xittenn
dragonstar57 Posted February 15, 2011 Posted February 15, 2011 (edited) I'm looking to build a co2 laser....not as worried about high power as much as a working unit from easy to find parts....the hardest part to find cheap would be the power supply....I can make this a little less hard by keeping the watts down.....I was wondering if a 10 mm tube 600mm long or even shorter with a good vacuum pump would keep the power demands low and still be a laser? Is there math for this? making a specific project goals would be a good idea. how powerful do you want your laser to be? how long do you want it to be able to run? how far should it maintain what ever power you want? how much do you want it to weigh? etc. i think i head somewhere that the highest efficiency a laser has ever reached was 10% can't remember where though... Edited February 15, 2011 by dragonstar57
Grouchy Hermit Posted February 16, 2011 Author Posted February 16, 2011 Some people always think the first thing to do is buy the book....and shes right, and way over my head. As for my goals...simple...I would like to learn about lasers.....the smaller the better. Most of the project, cooling system, vacuum pump, gas flow system, are things I have from other projects and would be the same if I decide to go larger later. My main concern is the power supply. While I understand that there are many variables such as temp. or pressure that apply, I was hoping for a more rule of thumb on tube size/ power. I'm aware that a TEA design would reduce power demands but it would make the tube a lot harder to build. I have some larger power supplies but I don't have the diodes I would need to covert them to DC and was hoping not to have to build that too. I have a 5.4kV 0.22mA D.C. power supply from something else and was wondering if I could make a small enough tube and put it under enough vacuum if it would work? While the whole ideal of this is to learn, It would take me too much time too work out XITTENN's equation ...I'm not sure where to apply the variables. I'm not worried about efficiency or building the perfect model at this point. As for how much power I would like to make...is 5 watts enough to burn paper held in front of a good lens? How long do I want it to last?....well a 5 watt laser is good for nothing, so that,s not a problem. I am going with the flowing gas design but that is because I'm not sure I can seal a vacuum tube. I understand that you have to watch what you say here, but the internet and ebay has made it so that anyone could build one of these with tubes made in China, someone coming here is looking for more than just a working unit.
dragonstar57 Posted February 16, 2011 Posted February 16, 2011 (edited) As for how much power I would like to make...is 5 watts enough to burn paper held in front of a good lens? that's done with 1/4 of a watt (250mW) jugging on that i would guess a 500-700 mW 1.5 watt will work well for setting paper on a fire Edited February 16, 2011 by dragonstar57
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