Path: utzoo!attcan!uunet!bu.edu!snorkelwacker!mit-eddie!uw-beaver!fluke!strong
From: strong@tc.fluke.COM (Norm Strong)
Newsgroups: sci.electronics
Subject: Re: Blue and UltraViolet LED's
Message-ID: <1990Jul19.145657.1700@tc.fluke.COM>
Date: 19 Jul 90 14:56:57 GMT
References: <17596.2699d803@uctvax> <1990Jul11.233848.29098@zoo.toronto.edu> <1551@oucsace.cs.OHIOU.EDU> <38692@cci632.UUCP> <1990Jul18.033929.13442@zoo.toronto.edu>
Organization: John Fluke Mfg. Co., Inc., Everett, WA
Lines: 26

In article <1990Jul18.033929.13442@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
}In article <38692@cci632.UUCP> rdi@ccird3.UUCP (Rick Inzero) writes:
}>Unless there's some problem with actually generating the UV from the 
}>light emitting diode chip itself...  So far, all I remember is postings 
}>that the plastic housing was the problem.
}
}That's a side issue; the hard part is getting short-wavelength emissions
}out of semiconductors at all.  (Nondestructively, that is! :-))  It's not
}a packaging problem that has delayed useful blue LEDs until quite
}recently.  The mechanisms and materials that fairly easily yielded IR,
}red, yellow, and green simply can't be stretched to blue, let alone
}further.  My impression is that the blue ones are a triumph over major
}difficulties, and nobody's in a hurry to tackle UV.

Yes, indeed.  And I'll bet the RIAA is heaving a big sigh of relief.  CDs
already last too long in their opinion.  They used to be able to sell an
LP with Brahms' 4th.  Now with CDs, they have to throw in at least the
Tragic Overture in order to be competitive.  

Can you imagine the problems of a CD that would last 3 hours? That's
about how long they'd last if the laser worked at 400nm. 

-- 

Norm Strong  (strong@tc.fluke.com)
2528 31st S.   Seattle WA 98144