Actually, this *is* a laser -- it's what's called "superradiant". A laser is defined by the stimulated emission, coherence, and sharply constrained emission wavelength(s), not by the resonant cavity -- but most laser systems require a resonant cavity in order to obtain enough amplification (by multiple beam passes through the medium) to produce a useful beam. A nitrogen laser (including those that use air) can have enough gain to make a good beam (albeit with high divergence) in a single pass.
But unfortunately, the laser spot is pretty lame looking. I'll make a video soon. For some reason, it doesn't work when it's humid out. It's still pretty cool though.
Well, what did you expect it to be? IMO we should be lucky to get any spot at all. To get a good quality beam you absolutely need a good wuality optical resonator, and here you don't have any resonator at all.
I got it to work yesterday (for about 5 seconds) but after that it began arcing through the dielectric. I can't get it working again. It could be the capacitor like you said, because it starts arcing at any voltage over 5-6 kv. And then It started arcing when the spark gap was pretty far apart. Maybe I'll try fixing that. Should I just redo the caps altogether?
@c4r0hv Ok, I change the dielectric to overhead transparency, and now I see a purple glow between the rails when it fires, but there are still lots of bright blue sparks. It isn't lazing either. All I can see is the reflection of the rails from the bright blue sparks. Do you think I should replace the rails?
PS I never actually saw the laser start working; all I saw was the purple glow before it died.
That's good that you see the purple glow (if it's really THE purple glow). Blue sparks should not be a problem as long as the glow is there. from my experience aligning the rails is not that hard, but acording to general opinion it's the hardest part of getting this kind of laser to work. So I suggest to not give up and try aligning it over and over :P What is the shape (cross section) of your rails? The discharge should occur in absolutely straight line.
@c4r0hv The spark gap fires 300 or so times every secon at 1mm, and the rails arc, but they have to be less 0.5 mm apart. The power supply is a 2n3773 flyback driver, and the setup of the laser is exactly like the one on hv wiki. The rails might be annodized, but that wouldn't explain the high firing rate of the spark gap.
Add resistor in series to slow down charging of the laser. That will decrease the firing rate. But first of all, increase the spark gap! It should be rather 10mm than 1mm... Minimum value depends on the system but IMO 1mm is far too low (assuming you don't have large, ball-shaped electrodes in the spark gap).
@c4r0hv Hmmm... I added a 30 kohm resistor and that helped with the firing rate, but now when it fires (the spark gap is 5mm now, if it's larger it starts to arc internally), I just see about ten bright sparks on the electrodes, and no lazing. I do know that other people have had this problem, but it doesn't seem like anyone knows how to fix it.
1. It's very bad that you have internal arcs. Technically, after a single shot like this you should replace the insulator that os broken.
2. Where are the sparks on the electrodes? All over the length and they appear in different locations, or always in the same spots? What's the shape of your electrodes (cross section)?
If the electrodes are good and are perfectly in parallel, it is still possible that the voltage is too low. You should be able to see a nice blue glow between the electrodes, besides the sparks that always appear somewhere. You should build the caps good enough to stand around 15kV. Higher voltage will definitely help with getting it to work.
And how do you check if it's lasing? I assume that you know that radiation emmited by N2 laser is invisible for human eye. You have to use some fluorescent stuff, like a white printer paper (most of them at least).
LASER=Light Amplification By Stimulated Emission of Radiation --> this IS a laser indeed since the n2 atoms emit via stimulated emission. Although it has no resonator.
I've been told at laser course at university that there must be a feedback, something that turns back generated radiation back to the laser material - that's in most cases a cavity made of mirrors. If there's no such feedback (even if stimulated emmission of radiation occurs) you can't call device a laser, it's an optical amplifier. That's what I've been told. There's also possibility that the definition of LASER has changed since that time :P
Actually, this *is* a laser -- it's what's called "superradiant". A laser is defined by the stimulated emission, coherence, and sharply constrained emission wavelength(s), not by the resonant cavity -- but most laser systems require a resonant cavity in order to obtain enough amplification (by multiple beam passes through the medium) to produce a useful beam. A nitrogen laser (including those that use air) can have enough gain to make a good beam (albeit with high divergence) in a single pass.
SilntObsvr 1 month ago
Sounds like a chain saw!
BankaiIchigo12345 7 months ago
But unfortunately, the laser spot is pretty lame looking. I'll make a video soon. For some reason, it doesn't work when it's humid out. It's still pretty cool though.
toadsEATbugs 1 year ago
@toadsEATbugs
Well, what did you expect it to be? IMO we should be lucky to get any spot at all. To get a good quality beam you absolutely need a good wuality optical resonator, and here you don't have any resonator at all.
c4r0hv 1 year ago
Comment removed
toadsEATbugs 1 year ago
I got it working! Yay!
toadsEATbugs 1 year ago
@toadsEATbugs
Congrats! Did you figure out what exactly was wrong?
c4r0hv 1 year ago
@c4r0hv Yeah, the rails weren't properly contacting the capacitor plates.
toadsEATbugs 1 year ago
I got it to work yesterday (for about 5 seconds) but after that it began arcing through the dielectric. I can't get it working again. It could be the capacitor like you said, because it starts arcing at any voltage over 5-6 kv. And then It started arcing when the spark gap was pretty far apart. Maybe I'll try fixing that. Should I just redo the caps altogether?
toadsEATbugs 1 year ago
@toadsEATbugs
Yes, replace the dielectric and I'd suggest to put more layers so that the caps can stand higher voltage.
c4r0hv 1 year ago
@c4r0hv Ok, I change the dielectric to overhead transparency, and now I see a purple glow between the rails when it fires, but there are still lots of bright blue sparks. It isn't lazing either. All I can see is the reflection of the rails from the bright blue sparks. Do you think I should replace the rails?
PS I never actually saw the laser start working; all I saw was the purple glow before it died.
toadsEATbugs 1 year ago
@toadsEATbugs
That's good that you see the purple glow (if it's really THE purple glow). Blue sparks should not be a problem as long as the glow is there. from my experience aligning the rails is not that hard, but acording to general opinion it's the hardest part of getting this kind of laser to work. So I suggest to not give up and try aligning it over and over :P What is the shape (cross section) of your rails? The discharge should occur in absolutely straight line.
c4r0hv 1 year ago
Help! I made one but it doesn't laze. I have no idea why :(
toadsEATbugs 1 year ago
@toadsEATbugs
Explain what's your results.
c4r0hv 1 year ago
Comment removed
toadsEATbugs 1 year ago
@c4r0hv The spark gap fires 300 or so times every secon at 1mm, and the rails arc, but they have to be less 0.5 mm apart. The power supply is a 2n3773 flyback driver, and the setup of the laser is exactly like the one on hv wiki. The rails might be annodized, but that wouldn't explain the high firing rate of the spark gap.
toadsEATbugs 1 year ago
@toadsEATbugs
Add resistor in series to slow down charging of the laser. That will decrease the firing rate. But first of all, increase the spark gap! It should be rather 10mm than 1mm... Minimum value depends on the system but IMO 1mm is far too low (assuming you don't have large, ball-shaped electrodes in the spark gap).
c4r0hv 1 year ago
@c4r0hv Hmmm... I added a 30 kohm resistor and that helped with the firing rate, but now when it fires (the spark gap is 5mm now, if it's larger it starts to arc internally), I just see about ten bright sparks on the electrodes, and no lazing. I do know that other people have had this problem, but it doesn't seem like anyone knows how to fix it.
toadsEATbugs 1 year ago
@toadsEATbugs
1. It's very bad that you have internal arcs. Technically, after a single shot like this you should replace the insulator that os broken.
2. Where are the sparks on the electrodes? All over the length and they appear in different locations, or always in the same spots? What's the shape of your electrodes (cross section)?
c4r0hv 1 year ago
@toadsEATbugs
If the electrodes are good and are perfectly in parallel, it is still possible that the voltage is too low. You should be able to see a nice blue glow between the electrodes, besides the sparks that always appear somewhere. You should build the caps good enough to stand around 15kV. Higher voltage will definitely help with getting it to work.
c4r0hv 1 year ago
@toadsEATbugs
And how do you check if it's lasing? I assume that you know that radiation emmited by N2 laser is invisible for human eye. You have to use some fluorescent stuff, like a white printer paper (most of them at least).
c4r0hv 1 year ago
Do you know the materials to build the NORMAL N2 laser?
keira97 1 year ago
@keira97
Well, you would need:
- fast high voltage capacitors
- source of clear N2 gas
- mirrors for the resonant cacity
- some precise mechanics for aligning them
- you need to make a tube for the gas, so probably some silica glass for brewster windows will be needed
That's all I can think of at the moment.
c4r0hv 1 year ago
is this the tea nitrogen laser?
keira97 1 year ago
@keira97
yep
c4r0hv 1 year ago
LASER=Light Amplification By Stimulated Emission of Radiation --> this IS a laser indeed since the n2 atoms emit via stimulated emission. Although it has no resonator.
diegoribadacunha 1 year ago
looks like a TEA laser to me
anorwood84 1 year ago
It IS a laser. It doesn't need an optical cavity because it's superradiant.
swirlingabyss 2 years ago
I've been told at laser course at university that there must be a feedback, something that turns back generated radiation back to the laser material - that's in most cases a cavity made of mirrors. If there's no such feedback (even if stimulated emmission of radiation occurs) you can't call device a laser, it's an optical amplifier. That's what I've been told. There's also possibility that the definition of LASER has changed since that time :P
c4r0hv 2 years ago
sweet!^^
supressor2 3 years ago
Where I can get infos to to it?
What is more complicate?
Fredasp 4 years ago
Use google. Type "faq nitrogen laser" and check the first link.
c4r0hv 4 years ago
nice laser!! What are you using for a power supply? Whats your Hz?
CrashByron 4 years ago
100kV/20mA X-ray transformer with a variac. 50Hz.
c4r0hv 4 years ago
wtf 100 kV wow thats 2ooo W
supressor2 3 years ago