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Any charts with laser power vs it's abilities online? — Parallax Forums

Any charts with laser power vs it's abilities online?

CuriousOneCuriousOne Posts: 931
edited 2014-06-20 23:38 in General Discussion
Hello.

A friend of mine is experimentig with Open CV, so he built a platform, which identifies and tracks an objects.

He has an idea, to create a camera guided laser system, which will blast baloons in air, 100-150 feet away. He asked me, what power laser he should get, and I was not able to answer him. When looking online, there are a lot of demos of lasers with various powers doing neat tricks, however, there are no charts like

1w=blasted black baloon 10ft away
5w=blasted any color baloon 50ft away

and so on.

Any info on this?

spectrum is irrelevant, it can be either UV or IR (camera sees both).

Comments

  • PublisonPublison Posts: 12,366
    edited 2014-06-12 11:54
    Probably not an appropriate post here where Parallax is concerned.

    There are plenty of other sites that can provide the information that you are requesting.
  • CuriousOneCuriousOne Posts: 931
    edited 2014-06-12 12:04
    Sorry to hear, but I don't get the problem reason, parallax bans laser usage or?
  • PublisonPublison Posts: 12,366
    edited 2014-06-12 12:21
    CuriousOne wrote: »
    Sorry to hear, but I don't get the problem reason, parallax bans laser usage or?

    It's just when you get into those power areas, they need FDA approval and are hard to import to the US if you are not a distributor, signing all the appropriate papers.

    I would hate to see a Parallax forum promoting a less than US legal Laser.
  • CuriousOneCuriousOne Posts: 931
    edited 2014-06-12 13:08
    So if I understood properly, the powers needed for the task described, are far above than legally allowed levels?
  • Mike GreenMike Green Posts: 23,101
    edited 2014-06-12 13:41
    Yes. If it can explode a balloon, it can instantly blind someone. 5mW is dangerous if someone looks into the beam of a red laser. IR is worse because you can't see it. The power levels you're talking about are about 3 orders of magnitude higher.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2014-06-12 14:56
    In addition to what the others have said about laser forums being the better choice for this type of question, the power output in watts is just one factor. An opaque red balloon will pop with a red or near-IR laser, but the same laser may have no or delayed affect on a clear balloon. It has to do with heat absorption.

    Secondarily, collimated laser light is not subject to the usual inverse square law of non-coherent light. One foot, five hundred feet, it may have little difference with the right collimating optics.

    Anyway, your friend doesn't need to blast balloons to test his optical tracking system. Lasers at this output are not illegal per se, but the cheap ones from China are not imported legally, and lack all the required safety and emissions standards. Just as an example, the high output green lasers from China are known to put out excessive IR power FAR above legal limits -- the reason is that the light is pumped from an IR source and frequency doubled. They're supposed to filter out the IR, but these things are cheap, and they don't bother.

    Also bear in mind that even a legal high output laser is not legal for operation outside of its intended use. Firing a laser into the open sky is without a doubt not legal without an appropriate variance (special permit). And there's a snowball chance of getting such a variance.
  • pmrobertpmrobert Posts: 673
    edited 2014-06-12 15:16
    Here in south FL, USA,we've had a recent spate of people thinking it's great entertainment to illuminate commercial airliners and police helicopters with hobby lasers. Needless to say, there are severe federal penalties for this and law enforcement has zero sense of humor about anyone shining lasers into open air even without aircraft visible. There's a couple of them sitting in our county jail right now waiting to see if the federal judge will give them bail.
  • ajwardajward Posts: 1,130
    edited 2014-06-15 13:36
    As you may have noticed, there are a lot of =very serious= concerns regarding your friend's project. You can find any number of videos online of people using powerful laser diodes to burn, melt, burst things with no indication of what safety measures they are (OR NOT) taking. =:-|

    That said, I have a few 1000mW 808nm IR laser diodes I experiment with. Each is mounted in a housing, with the leads shorted, with a collimation lens designed for the wavelength. When I use one of the diodes, the housing is placed in a light sealed aluminum case. The diode leads remain shorted until all the case screws are in place.
    The target, in the case, is backed the 4 alternating layers of high density plastic and black anodized aluminum.
    Once the case is closed, the diode leads are "un-shorted" and connected to the power supply output (Battery pack is sitting across the room).
    Satisfied everything is "OK", I put on the goggles, connect the batteries, find the power switch, look away and push the button.

    Complicated? Yes it is! Do I have a healthy respect for the damage these things can cause? You bet your sweet posterior!!!!!!!!!!!

    I would never fire one of these into the air to "blast a balloon". Can you know for sure where the beam is going once the balloon is gone????

    I certainly don't want to stifle anyone's quest for knowledge, but be awfully darned sure y'all are taking steps ensure your safety and that of others!!!!!!!!

    Amanda

    Sign on the door to my office...

    IMG_20140615_133110.jpg
    1024 x 768 - 54K
  • CuriousOneCuriousOne Posts: 931
    edited 2014-06-15 23:54
    Beam actually can be shaped, if I'm not mistaken, to be concentrated only at certain distance. Right?
  • ajwardajward Posts: 1,130
    edited 2014-06-16 04:52
    CuriousOne wrote: »
    Beam actually can be shaped, if I'm not mistaken, to be concentrated only at certain distance. Right?

    It can, but you have to consider, at the power levels you mentioned, on either side of that focus point you're still going to have a whole lot of light energy that can destroy someone's vision.

    @
  • Bruce SmithBruce Smith Posts: 5
    edited 2014-06-16 05:30
    I think color balloon will be blew off with a working voltage of 3V, 125mW with the beam diameter of 3 - 3.5
  • ercoerco Posts: 20,256
    edited 2014-06-16 10:53
    I actually have a black-balloon-popping green laser seek & destroy robot on my to-do list, but it will have numerous safety checks, and the laser will be permanently aimed parallel to the floor, just an inch or so above ground level. It will use a low-power pulsed red laser to locate reflectors on the balloon bases, and only then activate the high-power laser (and pre-warning siren) briefly, turning it off after hearing a pop or a default timeout. I agree that tracking and sweeping a continuous high-power laser beam angling upwards is not wise.
  • GenetixGenetix Posts: 1,754
    edited 2014-06-16 11:05
    Wow Amanda, a class 4 device. I can't remember if the laser welder I used had a class 3 or 4 laser. Because of the safety features though the whole unit was only class 1.
    I vaguely remember what the different classes were except for most laser pointers are class 1. I know it has to do with the power output.
  • CuriousOneCuriousOne Posts: 931
    edited 2014-06-16 12:53
    Side question- I have brand new, in original wooden crate, new old stock lab grade laser. Have no idea what it uses for beam generation, but I think it is gas filled laser, since I see central glass tube when looking inside. It's about 4 feet in length and about 10x10 inches in shape. The big problem is, I'm missing the power supply. What power it can be? considering it was made in mid 70s...
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2014-06-16 13:03
    CuriousOne wrote: »
    Side question- I have brand new, in original wooden crate, new old stock lab grade laser. Have no idea what it uses for beam generation, but I think it is gas filled laser, since I see central glass tube when looking inside. It's about 4 feet in length and about 10x10 inches in shape. The big problem is, I'm missing the power supply. What power it can be? considering it was made in mid 70s...

    The laser is, with little doubt, gassed out. You could have it refilled, but that's very expensive.

    That size of laser, even for one built in the 70s, sounds like an argon tube. If there's no water inlet for cooling, it's likely not more than 100-500 mW (or so). That's still pretty bright, especially as our eyes are more sensitive to the blue/green spectrum. The higher wattage argon lasers often used water cooling. That would be obvious by the pipe fittings to the laser housing.

    Power supplies for laser tubes tend to be at least as expensive as the tubes themselves. The power supplies for tubed lab lasers were very stable, adding to their high cost, in order to provide the accuracy required in whatever they were using the laser for.
  • CuriousOneCuriousOne Posts: 931
    edited 2014-06-16 13:10
    The laser assembly itself is packed into thick, sealed polyethylene bag, with several sacks of silica gel inside. The bag itself looks intact, so this is the reason why I haven't opened it yet. Tomorrow I'll try to take some pictures of it.
  • GenetixGenetix Posts: 1,754
    edited 2014-06-16 13:32
    CO2 and ruby are very old technologies so it's most likely one of them.

    Is there an ID label or any documentation that could give company or model number?
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2014-06-16 15:23
    A ruby laser measuring that size would be out of a James Bond movie, I think.

    Bond: Do you expect me to talk?
    Goldfinger: No, Mr. Bond, I expect you to die!
  • msrobotsmsrobots Posts: 3,709
    edited 2014-06-16 20:07
    And always remember what @Hal Albach has In his sig.

    Do not look directly into laser with remaining good eye...


    Enjoy!

    Mike
  • ercoerco Posts: 20,256
    edited 2014-06-16 21:02
    A ruby laser measuring that size would be out of a James Bond movie, I think.

    Yup. My older brother made a laser using a ruby rod back in the 1970s. Around $75 back then IIRC, powered by two of those one-use flashbulbs that actually melted the glass. It was only about 2" long and maybe 5/16" diameter.
  • ajwardajward Posts: 1,130
    edited 2014-06-16 22:05
    Genetix wrote: »
    Wow Amanda, a class 4 device. I can't remember if the laser welder I used had a class 3 or 4 laser. Because of the safety features though the whole unit was only class 1.
    I vaguely remember what the different classes were except for most laser pointers are class 1. I know it has to do with the power output.

    From the OSHA website: "Class IV: High power lasers (cw: 500 mW, pulsed: 10 J/cm2 or the diffuse reflection limit) are hazardous to view under any condition (directly or diffusely scattered) and are a potential fire hazard and a skin hazard. Significant controls are required of Class IV laser facilities."

    The datasheet on my diodes indicated 1000mW cw. The unfocused beam can melt plastic and burn paper.
    This project has been on the back burner for a while tho'... just too many shiny things scattered around my desk. Most recently a solar cell phone charger.

    @
  • Heater.Heater. Posts: 21,230
    edited 2014-06-17 13:24
    CuriousOne,

    For God's sake tell your "friend" not to be such a frikken idiot.

    Stop to think for one minute. 1 Watt is 1 Joule per second. 1 Joule is the amount of energy required to raise 4 grams of water by 1 degree Centigrade.

    Now imagine all that power concentrated into a tiny sub millimeter area and applied to the few micrograms of retina in your eyeball. Poof instant eye damage.

    There is a reason why I have just been reading about rewards of thousands of dollars being offered in the states for information on people shining such lasers at aircraft. Sorry I don't have a link to an article at hand.

    And, about that vision system, can one be sure it knows the difference between a balloon and a human head?!

    Anyway, for your "laser damage" chart look here http://en.wikipedia.org/wiki/Laser_safety
  • GenetixGenetix Posts: 1,754
    edited 2014-06-17 15:34
    Congrats on VIP status, Heater.

    Like everything else sooner or later we will all need special training or special permits because of all the idiots doing stupid things.

    Amanda, when a company technician would calibrate the laser welder I used to work a thick shroud would be placed around the unit to protect the rest of us who worked around it.
    We also measured the laser output daily so that engineering could monitor it's condition.
    One poor technician accidently crashed the test stand crash into one of the laser heads and it took almost 2 months for engineering to readjust and revalidate the unit.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2014-06-17 16:23
    erco wrote: »
    Yup. My older brother made a laser using a ruby rod back in the 1970s.

    Is this the same brother with the Wurlitzer? How come he ended up being the really cool one in the family? Hummmmm?
  • ercoerco Posts: 20,256
    edited 2014-06-17 17:23
    Is this the same brother with the Wurlitzer? How come he ended up being the really cool one in the family? Hummmmm?

    Yes, I've lived (if you can all it that) in the shadow of his string of stunning successes all my life.
  • Peter KG6LSEPeter KG6LSE Posts: 1,383
    edited 2014-06-20 22:32
    for the love of rods and cones ....... just buy legal 5 mW diodes and leave the HP stuff to folks whom have the time to Learn the hazard charts . Do this and Understand the Reason to them and the rules and then you can play with in those rules .


    EG.
    I just got a slick Argon Ion laser ( small air cooled ) this week From a Proff at a university near by.
    Its 20-70 mW or so ,,,,,,, I use it on the lower end 30-40 so I can use it for Holograms in a few weeks.

    3 top rules for lasers ........

    1 If you don't 100% understand Read . stop and read some more .

    2 Prior to emission . Sit back and Become a photon . understand and Know where the beam Might go .
    as to prevent a beam from bouncing back to you or some one else . use Beam blocks ( I used my matte black painted Old laptop as a beam block for the Ar Ion yesterday.


    3 Use eyewear and UNDERSTAND the Idea of OD . Its not that hard .

    Skin can heal from all kinds of burns .... large CO2 lasers aside . the majority of the HP pointers are not gonna amputate a limb .
    If you feel a burn Trust me .. like a hot stove you WILL move out of the beam.
    Eyes dont Heal like skin ..... spend the $$$ and get rated Real Laser OD glasses



    I have my own rather strict guidelines here in my home lab.

    Pointer ( off the rack 5mW or less ) Needs no eye wear. they are momentary and thus are unlikely to be walked in to there own beam. ( usefull to plan a aiming beam! for a larger laser!)

    HeNe all of mine are under 10 mW rated My big HeNe does like 6 ........ Its Old :(
    HeNe's are not exempt unless they are on a galvo for scanning .

    I have one 20-30mW Red diode system I rarely use as the HeNe is better in every way . it has to be used with eyewear.

    The Ar-Ion is a Beast! light is one of many hazards of it . the PSU is a Death trap of caps and non isolated parts.

    The Ion is the most powerful CW laser I have here and I dont want one any larger as I have no need for power beyond 20 mW. It can do up to 70 mW

    Its also required to have eyewear ..

    Once I get the thing working up to spec Ill be running it as low as Its can do with in reason ..
    I suspect I can get down to 30mW


    https://www.flickr.com/photos/peterthethinker/14439483446/in/photostream/


    Might I suggest you Read the SAMS LASER FAQ as night time reading ......

    In-fact Sam and I have been chatting in email the past few days on my Argon system ......

    [IMG]https://farm3.staticflickr.com/2914/14277410957_09d83fb10a_z.jpg[/IMG ( timer pic ) Just be safe and treat a laser as a loaded canon..[/img]
  • Too_Many_ToolsToo_Many_Tools Posts: 765
    edited 2014-06-20 23:38
    Excellent discussion.

    Take the safety warnings very seriously...your sight depends on it.

    Sam's FAQ is a good start for general knowledge.

    As a pilot, I strongly support prosecution of any idiot who use lasers on aircraft.
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