Path: utzoo!attcan!uunet!dino!uxc.cso.uiuc.edu!uxc.cso.uiuc.edu!ux1.cso.uiuc.edu!uxe.cso.uiuc.edu!mcdonald
From: mcdonald@uxe.cso.uiuc.edu
Newsgroups: comp.graphics
Subject: Re: Color desktop scanners (a technical
Message-ID: <46900036@uxe.cso.uiuc.edu>
Date: 24 Aug 89 23:22:25 GMT
References: <1869@ucsd.EDU>
Lines: 22
Nf-ID: #R:ucsd.EDU:1869:uxe.cso.uiuc.edu:46900036:000:954
Nf-From: uxe.cso.uiuc.edu!mcdonald    Aug 24 10:11:00 1989



>I have been told a white light laser does not exists because
>cramming all those frequencies together they start cancelling
>out and moving in different directions after some distance.

White light lasers, very genuine ones, really do exist. There is one
running right now about 30 feet above my head. The different colors do 
come out at different TIMES - but, do you care that one color
comes out 0.0000000000001 second before another? In any case, further
work is expect to get them all coming at out once anyway. Another
factor of three faster pulses and there would indeed be genuine,
all at once, white light. All the colors would come out in 
one pulse 0.0000000000000025 second long. 

I should add that these lasers are really something to behold. They
generate lots of oohs and aahs from the non-jaded person - laser 
tables 5x14x2 feet weighing 5 tons crammed full of hundreds of optical
parts. (This include amplifiers.) 

Doug McDonald