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Old 03-25-2010, 07:54 PM   #5190
Pie
Gone and done
 
Join Date: Sep 2001
Posts: 4,808
Quote:
Originally Posted by glatt View Post
I don't know what that means. Isn't 3.5 dB on the quiet side? It must be good if you are happy about it. What was making the noise?
The noise figure is a measure of the noise relative to the signal amplification. The lower, the better. A theoretically perfect optical amplifier has a 3 dB NF. the noise comes from what's called Amplified Spontaneous Emission (insert dirty joke here). In essence, the 'excited' atoms might emit a photon without waiting for an incoming signal photon, thereby creating a background 'hum' that has nothing to do with the signal to be amplified.

Anyways, my measurement was off -- it's really 4.02 dB. Still pretty kickin'.

Glatt -- have you been to the Udvar Hazy air & space museum, over by Dulles? We were there a couple of weeks ago. They've got the Enola Gay, the Global Flyer, and a SR-71 Blackbird. AND THE ENTERPRISE. The Freakin' ENTERPRISE. The U-H is also part of the Smithsonian. Highly recommended.
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