Why Do We Have Lasers, But Not 'Star Wars'-Style Lightsabers?

[micheal rosen]

The second something passes in front of the beam lasing action will cease. So you would get a quick "pulse" that uses all of energy currently resonating within the cavity and then it would would stop all together.

but if it was powerfull enough, maybe it would just burn it out of the way, and continue to lase?

 

[H2Oxide]

but if it was powerfull enough, maybe it would just burn it out of the way, and continue to lase?

Maybe, but if you were actually trying to cut through something you would not be able to sustain a population inversion due to the lack of light being reflected back into the medium.

 

[micheal rosen]

Maybe, but if you were actually trying to cut through something you would not be able to sustain a population inversion due to the lack of light being reflected back into the medium.

probably. still a fun thought though.

 

[micheal rosen]

Oh wow, I didn't even realize one could achieve that much power with those. My rookie knowledge of laser technology is not applicable in this theory.

yeah, in the cavities of most gas and crystal lasers, the resonant cavity has TONS of energy moving through it. heres a nice vid to demonstrate that: www.youtube.com/watch?v=lW4Uq_2VPhE

it always surprises me how much energy is in that resonant cavity, considering that HeNes are only like 2-3mW at the very most.

EDIT: oops, kinda double posted... oh well.

 

[Ricker]

yeah, in the cavities of most gas and crystal lasers, the resonant cavity has TONS of energy moving through it. heres a nice vid to demonstrate that: www.youtube.com/watch?v=lW4Uq_2VPhE

it always surprises me how much energy is in that resonant cavity, considering that HeNes are only like 2-3mW at the very most.

Wow, that's too cool! Thank you very much for sharing that, and replying to me.

 

[Pi R Squared]

yeah, in the cavities of most gas and crystal lasers, the resonant cavity has TONS of energy moving through it. heres a nice vid to demonstrate that: www.youtube.com/watch?v=lW4Uq_2VPhE

it always surprises me how much energy is in that resonant cavity, considering that HeNes are only like 2-3mW at the very most.

There are plenty of HeNe lasers that are 20mW or maybe more. The reason that most here that have them have ones that are from less than 1mW to 3mW is because those are the affordable ones.

https://mi-lasers.com/product/20mw-633nm-red-hene-laser-system-2/

Alan

 

[micheal rosen]

There are plenty of HeNe lasers that are 20mW or maybe more. The reason that most here that have them have ones that are from less than 1mW to 3mW is because those are the affordable ones.

https://mi-lasers.com/product/20mw-633nm-red-hene-laser-system-2/

Alan

i meant most HeNe's. some can even get up to 35mW, and i believe i saw a 50mW one once, not sure though.

 

[H2Oxide]

There are plenty of HeNe lasers that are 20mW or maybe more. The reason that most here that have them have ones that are from less than 1mW to 3mW is because those are the affordable ones.

https://mi-lasers.com/product/20mw-633nm-red-hene-laser-system-2/

Alan

Pretty sure the Spectra Physics 125A is rated at 50 mW! (using 633 nm optics of course )

Also I believe the MG 25-LHP-928-249 has a 75 mW label, not sure ho much it actually outputs though.

 

[crazyspaz]

yeah, in the cavities of most gas and crystal lasers, the resonant cavity has TONS of energy moving through it. heres a nice vid to demonstrate that: www.youtube.com/watch?v=lW4Uq_2VPhE

it always surprises me how much energy is in that resonant cavity, considering that HeNes are only like 2-3mW at the very most.

EDIT: oops, kinda double posted... oh well.

Yes but that energy is sausage if something blocks the path in between the mirrors.

Lightsaber=magical energy arc
Laser=finitely powerful

Even the massive CO2 laser once mounted on air force place that could destroy other moving targets wouldn't be the same as a lightsaber. And sticking something inside a resonance cavity would be pointless, because once you block one stream of photons bouncing back and forth, there goes all the power.

 

[micheal rosen]

Yes but that energy is sausage if something blocks the path in between the mirrors.

Lightsaber=magical energy arc
Laser=finitely powerful

Even the massive CO2 laser once mounted on air force place that could destroy other moving targets wouldn't be the same as a lightsaber. And sticking something inside a resonance cavity would be pointless, because once you block one stream of photons bouncing back and forth, there goes all the power.

Can't I atleast dream XD

I agree, it would take an absolutely insane amount of energy to blast through things will the resonant cavity energy.

 

[Illuminum3415]

So how much energy do you think could be stored in a typical AA battery then?

lol.... okay, where do we start. A typical AA as in Zn/MnO2, NIMH, NiCd, NiZn, Li-FeS, LiMnO2, LiCoO2, LiMn2O4, LiFePO4, or LiNiCoAlO2? Different chemistry exhibit different electrical characteristics, all of which can exist in the same physical volume. That is, a cylindrical space measuring 14mm x 50mm
Stored energy cannot be translated to usable energy largely because of three primary obstacles. Internal resistance, Contact resistance, Ambient temperature.

If you don't care for volts, an NIMH AA can happily put out 10A. Not all 14500 batteries are the same, it's like asking, "How many beers can Ted down in one hour?" Who's Ted? XD


On the side of intuition, assuming that you do possess the necessary energy storage as mentioned, how do you stop a beam of light [laser is simply coherent light] halfway even when the medium in which is is traveling possesses little to no absorption abilities?

Something also to think about is that the laser does not have to be continuously on. Most diodes can withstand a little over-current when pulsed as opposed to be operated continuously. The relationship between output and forward current is non-linear, as is the relationship between forward voltage and current. Increasing the drive current to the diode by a factor of two may result in an increase in power greater than a factor of two. The same may hold true for output. However, doubling the current may not double the output, and in fact, above a certain point, light output may even decrease as the internal temperature of the die rises. However, batteries last a lot longer if the laser is only running half the time, say 50% duty cycle. etc.


that's my take on the "most difficult obstacle" in the whole mess.

 

[VisibleGreen]

lol.... okay, where do we start. A typical AA as in Zn/MnO2, NIMH, NiCd, NiZn, Li-FeS, LiMnO2, LiCoO2, LiMn2O4, LiFePO4, or LiNiCoAlO2? Different chemistry exhibit different electrical characteristics, all of which can exist in the same physical volume. That is, a cylindrical space measuring 14mm x 50mm
Stored energy cannot be translated to usable energy largely because of three primary obstacles. Internal resistance, Contact resistance, Ambient temperature.

If you don't care for volts, an NIMH AA can happily put out 10A. Not all 14500 batteries are the same, it's like asking, "How many beers can Ted down in one hour?" Who's Ted? XD


On the side of intuition, assuming that you do possess the necessary energy storage as mentioned, how do you stop a beam of light [laser is simply coherent light] halfway even when the medium in which is is traveling possesses little to no absorption abilities?

Something also to think about is that the laser does not have to be continuously on. Most diodes can withstand a little over-current when pulsed as opposed to be operated continuously. The relationship between output and forward current is non-linear, as is the relationship between forward voltage and current. Increasing the drive current to the diode by a factor of two may result in an increase in power greater than a factor of two. The same may hold true for output. However, doubling the current may not double the output, and in fact, above a certain point, light output may even decrease as the internal temperature of the die rises. However, batteries last a lot longer if the laser is only running half the time, say 50% duty cycle. etc.


that's my take on the "most difficult obstacle" in the whole mess.

I meant if we could put electrons directly into a cylinder shape of a typical AA sized battery. Like how much could be compressed?

 

[Illuminum3415]

I meant if we could put electrons directly into a cylinder shape of a typical AA sized battery. Like how much could be compressed?

In that case It would probably be close to a supercap/MLCC that fit the dimensions of an AA battery