[Laser] Lasers vs LEDs & ARRL contests

[Dexter McIntyre W4DEX]

W0ZQ at aol.com wrote:
> Dex, by "certain band" do you mean ham band(s) ?  Or, do you mean  that the 
> radiation is limited to any certain bandwidth (by the manufacturer)  ?
>
> Could you elaborate on "certain band" ?
>
>   
Jon,

By certain bandwidth I mean any light that most of it's output is 
confined to a narrow spectrum.  I guess this would apply to most any 
solid state light emitting device.

I've often wondered why the current rules just specified a stage of 
electronics on the receive end.  Why not require the transmitted light 
to be modulated?  Doesn't everyone who is serious about light 
communication use a modulated signal?

The present rule about a valid laser contact seems odd to me.  "While no 
minimum distance is specified for contacts, equipment should be capable 
of communications at a range of at least 1 km."  So a contact made at 1 
meter distance is ok as long as the equipment is capable of 1 km.   
????     I think even a minimum contact distance of 1 km isn't much of a 
challenge.  But as you can probably tell I'm not very knowledgeable 
about communications in the light spectrum.  However I do still have my 
first light transmitter from 30+ years ago.  A HeNe tube modulated with 
a fan :)  Never tried more than a 2.5 mile path but that was rather easy.

Thanks for bringing up the subject Jon.

Dex