Small Laser Components

[faceman28208@yahoo.com]

For a model I am making, a couple of small lasers could improve it. I
know there are laser pointers. The effect I would like is just that of
a beam, at most a two foot range.

1. Can anyone recommend any components/sources?
2. Are there any safety issues? I don't intend to have anyone look
into it but do I need to be concerned about someone doing something
stupid? I would trade power for for safety.

 

[Phil Allison]

<faceman28208@yahoo.com>

For a model I am making, a couple of small lasers could improve it. I
know there are laser pointers. The effect I would like is just that of
a beam, at most a two foot range.

** Lasers do not make visible beams of light any more than a torch does.

Creating a visible beam requires the air to be laden with particles, like
fog or smoke.

Been watching too many Hollywood movies have we ?




..... Phil

 

[IanM]

Phil Allison wrote:

faceman28208@yahoo.com

For a model I am making, a couple of small lasers could improve it. I
know there are laser pointers. The effect I would like is just that of
a beam, at most a two foot range.



** Lasers do not make visible beams of light any more than a torch does.
Depends on the output power. At around a megajoule per sqare cm, the

beam in air will definately be visible from the side (given appropriate
indirect imaging equipment so you've still got eyes to see it)!

Creating a visible beam requires the air to be laden with particles, like
fog or smoke.
I am inclined to agree with you however however that small (i.e. man

portable) laser systems dont produce a beam visible off axis.

Been watching too many Hollywood movies have we ?

It always cracks me up when they show us a handheld laser gun without a
50Kg backpack for the power supply!

 

[faceman28208@yahoo.com]

Just to clarify here....it's a display model. Just trying to give the
appearance of weapons firing. I don't expect a hollywood solid blue
beam....just some reflections from the dust in the air is enough. If
that was not enough, I was thinking about putting some dry ice under
it. In other words, i'd like to get a little more concentrated than a
focused LED beam. Just enough for kids at a model show to say "wow!"

So, any component suggestions?

 

[Michael Black]

On Wed, 10 Dec 2008, IanM wrote:

Phil Allison wrote:
faceman28208@yahoo.com

For a model I am making, a couple of small lasers could improve it. I
know there are laser pointers. The effect I would like is just that of
a beam, at most a two foot range.



** Lasers do not make visible beams of light any more than a torch does.
Depends on the output power. At around a megajoule per sqare cm, the beam in
air will definately be visible from the side (given appropriate indirect
imaging equipment so you've still got eyes to see it)!

Creating a visible beam requires the air to be laden with particles, like
fog or smoke.
I am inclined to agree with you however however that small (i.e. man
portable) laser systems dont produce a beam visible off axis.

Been watching too many Hollywood movies have we ?

It always cracks me up when they show us a handheld laser gun without a 50Kg
backpack for the power supply!

Captain Laser from 40 years ago had a big backpack, and while I can't put

my hands on it easily to check, I always thought it was to power the
laser and not an air supply.

But then, that backpack held two AA batteries, and there was no laser,
just a light bulb of some sort, with colored plastic over it to give it
color. The only LEDs at that point were in the laboratory, at the least
very expensive.

The problem with a laser is that you can't guarantee that nobody will
look on it straight on, and that's where the danger is, the concentration
of light in a narrow beam.

Michael

 

[Rich Grise]

faceman28208@yahoo.com wrote:

For a model I am making, a couple of small lasers could improve it. I
know there are laser pointers. The effect I would like is just that of
a beam, at most a two foot range.

1. Can anyone recommend any components/sources?
2. Are there any safety issues? I don't intend to have anyone look
into it but do I need to be concerned about someone doing something
stupid? I would trade power for for safety.

Take up smoking. ;-)

Cheers!
Rich

 

[Phil's Nemesis]

"Phil Allison" = "Congenital ignorant CRETIN" :

Creating a visible beam requires the air to be laden with particles, like
fog or smoke.

** Shame how it totally does NOT require that - pal.

Never heard of Rayleigh Scattering?

http://en.wikipedia.org/wiki/Rayleigh_scattering

See subsection on "scattering from molecules":

http://en.wikipedia.org/wiki/Rayleigh_scattering#Rayleigh_scattering_from_molecules

Means that scattering can and DOES occur from the mere gas molecules
(and atoms in the case of noble gases) with ZERO suspended dust or
other crap present.

Causes beams to become visible in PURE gas at only moderate powers.

Scattering intensity increases with size of scattering centres (e.g.
gas molecules or atoms), and also with the fourth power of frequency.

Using larger gas molecules (e.g. SF6) visibly increases scattering
intensity and therefore visibility of the beam. Using smaller molecules
or atoms (e.g. He gas, which consists of individual He atoms) reduces
the visibility of the beam compared to air.

Been watching too many Hollywood movies have we ?

** Been dodging physics classes have we - pal?

What a TOTALLY ASININE IGNORANT ASD fucked PIG !!!

PLEASE Go away for the sake of us all! And LEARN SOMETHING -
you CRIMINALLY INSANE AUSSIE *NUTCASE*


..... Phil's Nemesis

 

[John Doe]

"Phil's Nemesis" <fleetie@fleetie.demon.co.uk> wrote:

"Phil Allison" = "Congenital ignorant CRETIN" :

....

PLEASE Go away for the sake of us all! And LEARN SOMETHING -
you CRIMINALLY INSANE AUSSIE *NUTCASE*

A fitting description IMO, except the "criminal" part suggests he has a
life.


--
The first big front wheel rollerblades.
http://www.flickr.com/photos/27532210@N04/3056505603