Alt-BEAM Archive

Message #13245



To: "'beam@sgiblab.sgi.com'" beam@sgiblab.sgi.com
From: Wilf Rigter wilf.rigter@powertech.bc.ca
Date: Sun, 9 Apr 2000 10:00:48 -0700
Subject: RE: Wacky ideas floating around


Laser light is pure and simple.

It travels long distance without spreading, can carry very high density of
information and can be focused (concentrated) on a very small area. This is
used in laser radar, fiberoptic cables, CD-ROMs, holograms and tattoo
removal amongst others.

The first laser was an optically pumped ruby rod invented in 1960 by Harold
Maiman.

Laser light is generated just like the name says:

LASER = Light Amplification by Stimulated Emission of Radiation

Simplified from my cobwebbed memory:

a) A ruby rod of the right (wave) length, with both ends mirrored but with a
small hole in one mirror, is placed inside a helical xenon gas filled strobe
lamp.

b) A high voltage capacitor is discharged through the xenon lamp (just like
a camera flash) producing an intense white flash.

c) Many photons from the white light are absorbed by the ruby molecules
exciting them to a higher energy state.

d) When the excited ruby molecules drop back to their ground state they emit
a monochrome red photon (fluorescence).

e) This monochrome light is similar to LED light but it is generated like
the light slowly given of by fluorescent paints, etc. after
exposure to high energy light.

f) Many of the red photons pass out the sides of the ruby rod but some
travel along the axis and are reflected by the mirrors.

g) When a red photon passes through a high energy state molecule it
"stimulates" that molecule to release it's photon which starts
to travel in lockstep with the original photon. (phase coherent).

h) Each time the photons are reflected back into the ruby rod they release
more photons.

i) As more and more molecules are stimulated to release their energy, the
number of red photons traveling back and forth in lockstep between the
mirrors increases rapidly and in a few microseconds, all stored energy is
released in a burst of phase coherent monochrome red light, emitted from
the small hole in the one end mirror which, for example, can be focused on a
very small spot to produce intense localized heating and evaporate the ink
and stained tissue of a skin tattoo.

This LASER mechanism is very interesting because it is a form of "emergent
behaviour" related to the principles we have discussed for generating
"herding" behaviour in a group of photopoppers. This is similar to using an
IR emitter (TV remote etc) and series resistor connected in parallel with a
motor to signal when one photopopper "pops" which is then picked up by the
photodiodes of the other photopoppers to trigger an avalanche of "pops"
causing them in move in lockstep (wow, they communicate!).

Lasers, photopoppers, herding photons : Beam embedded in the art of science
and technology.

wilf

> -----Original Message-----
> From: Dave Hrynkiw [SMTP:dave@solarbotics.com]
> Sent: Saturday, April 08, 2000 4:46 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: Wacky ideas floating around
>
> At 05:15 PM 4/8/2000 , Timothy Flytch wrote:
> >Ok Dave,
> >What I was thinking about was the old ruby lasers... you take a ruby and
> >grind it into a kinda double ended bullet shape with a whole running have
>
> >way down the center axes... This is then surrounded by a light ... when
> >the light is switched of the light builds and then is released in one
> >coherent beam out of the hole... as long as the supply light is on, the
> >lite is "stored up" in the ruby...
>
> I don't think you can consider this as "storing" light, as it's taking
> white light and converting it to a different kind of light (red cohesive
> beam).
>
> I haven't heard of ruby-rod lasers having a hole in the middle; just a
> cylinder with one flat end fully mirrored, and the other flat end
> partially
> mirrored so the red light can escape out. Is this one you're referring to
> a
> variation on the same theme?
>
> The only think I can think of that comes close to the concept of "storing
> light" is the glow-in-the-dark effect in the plastic of my daughter's
> water
> vaporizer!
>
> -Dave
> ---------------------------------------------------------------
> "Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
> that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
> 2 vowels. Pronounciation? _SMITH_".
> http://www.solarbotics.com



13246 Sun, 9 Apr 2000 14:06:58 EDT Re: Wacky ideas floating around beam@sgiblab.sgi.com SkavenArmy@cs.com well couldnt you just put some metal insulation around the whole enclosure
then collect it from that(is emf +v or -v?)



jay z



13247 Sun, 9 Apr 2000 11:12:40 -0700 RE: Zijn er ook Nederlandse beamers? "'sebastiaan_van_v@hotmail.com'" Wilf Rigter Heheh! Just couldn't resist using my rusty old Dutch ( Holland, potato
chips, etc) which incidentally drove my spellchecker crazy.

Sebastiaan wrote:=20

[Wilf's translation]=20

> Are there any Dutch beamers?=20
>I am one and if you think it might be fun, =20
>you can email me at sebastiaan_van_v@hotmail.com

Yes indeed, I am one too but who has lived in Canada now for the last =
forty
years!
Email might be fun although I don't write fluently in Dutch anymore.=20
Have you already read the famous Suspended Bicore Article(
http://www.beam-online.com/Bicore_article/select.htm) by fellow dutch
beamer Wouter Brok?

[Wilf's translation]=20

Ja hoor, ik ben er ook =E9=E9n maar die nu al voor veertig jaar in =
Canada
gewoont heeft!
"Mail" zou wel leuk zijn, al hoe wel ik niet zo goed meer in Nederlands =
kan
schrijven.=20
Heb je ook het bekende "Suspended Bicore Article" (
http://www.beam-online.com/Bicore_article/select.htm ) door Nederlandse
beamer, Wouter Brok geleezen ?=20

met groeten
=20
wilf

> -----Original Message-----
> From: sebastiaan van Vliet [SMTP:sebastiaan_van_v@hotmail.com]
> Sent: Sunday, April 09, 2000 5:21 AM
> To: beam@sgiblab.sgi.com
> Subject: Zijn er ook Nederlandse beamers?
>=20
> Ik ben er wel =E9=E9n!
>=20
> Als je het leuk vindt mail me dan!
>=20
> sebastiaan_van_v@hotmail.com
>=20
>=20
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com



13248 Sun, 9 Apr 2000 14:17:32 EDT sumop beam@sgiblab.sgi.com SkavenArmy@cs.com i am not familiar wth the rules for the sumo competition , but if you could
make a sonar tyoe thing fr your sumo , or have it spray the other one with an
ir emitting film or reflective surface, you could trak it that way , or you
could have your bot stick a beacon to the other bot

ja z



13249 Sun, 9 Apr 2000 14:58:54 -0400 Re: 'Nother photovore question "Ben Hitchcock"
> Try shorting the FLED briefly with a piece of wire.
>
> Then try shorting the base of the PNP transistor (BRIEFLY!) to ground.
> Let us know if this makes it work.


Mine is the 1381J type, and after some wiggling of random parts it seems to
work now. Some wire must not have been pushed all the way in.


> ----------
> >From: "William Cox"
> >To:
> >Subject: Re: 'Nother photovore question
> >Date: Sun, 9 Apr 2000 6:23
> >
>
> > I have the EXACT same problem with the FRED circuit!! It's *very*
> > aggravating...
> > -William



Hope it helped you though : )

-Zac

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