[Laser] laser ratings

[Tim Toast]

here is a wiki page that has the official numbers or limks to 
them i believe:
http://en.wikipedia.org/wiki/Laser_safety

and this graph in particular:
http://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png



--- On Fri, 7/23/10, laser-request at mailman.qth.net <laser-request at mailman.qth.net> wrote:
> 
> Tim:
> 
> I see renewed discussion of the contest.  I have been
> away from the issue for 
> some time, and have lost contact with the rules, contest
> site.  Could you send 
> me the site?  I may be interested.  I will be
> working on long distance laser 
> comm:   http://www.microlaunchers.com/7816/L3/laser/laser-link.html
> 
> I would be using low power lasers to enter if I did.
> 
>     Charles Pooley       
>           KD6HKU
>     ckpooley at sbcglobal.net
>     661 824-4095
>     http://www.microlaunchers.com/
> 
> 
> 
> Message: 3
> Date: Thu, 22 Jul 2010 22:39:51 -0500
> From: "James Whitfield" <n5gui at cox.net>
> Subject: [Laser] laser ratings
> To: <laser at mailman.qth.net>
> Message-ID:
> <62ADCE0E71D242EEAFAA33904FCF9763 at Sony2G4>
> Content-Type: text/plain;   
> charset="iso-8859-1"
> 
> Recent discussions about laser power have revealed a gap in
> my understanding of such things.
> 
> I have a laser pointer that I have been using for several
> years for demos and as the emitter element on an MCW
> transmitter.  The label says its maximum power output
> is 4 mWatt.  It is built for two AA batteries.  I
> measured the input voltage.  It seems noticeably weak
> at 2.5 volts and it draws 16 mA.  With fresher
> batteries, it seems full power using 2.8 volts drawing 33
> mA.
> 
> With my MCW transmitter, I pulse it with about 30 mA at
> about 400 Hz, not bothering to try to control the voltage,
> just a hard current limit, pulsed or not.
> 
> The numbers say its input power is 40 mWatt for the weak
> condition, and over 90 for the bright.  I am pretty
> sure that most of that power is actually going into the
> laser diode.  If the rating is output power, then the
> conversion efficiency seems to be less than 10%.  I
> suppose that is on par with an underdriven tube type class A
> amplifier.
> 
> Anyway, I was wondering if someone can explain the laser
> power rating system, or maybe provide a link where that
> information is available.
> 
> Thanks in advance.
> 
> 
> James
>  n5gui
> 
>