[time-nuts] optically pumped frequency standards

Chris Caudle chris at chriscaudle.org
Fri Jan 14 15:52:26 UTC 2011


On Fri, January 14, 2011 12:02 am, Bruce Griffiths wrote:
> Kernco, Symmetricom.

Interesting reference, I was not previously familiar with Kernco.

The description of their "Coherent Population Trapping" method rubidium
standard says that the laser diode is frequency modulated to generate two
wavelengths.
http://www.kernco.com/index2.php?page=cpt

I thought that solid state light sources, either LED or laser diode, had
the wavelength set by the chemical composition that determined the
bandgap.  How would you frequency modulate a diode light source?  Is that
a feature common to all laser diodes, or would the need for tuning
capability exclude the low cost diodes mentioned previously ( I believe
from Sharp, intended for CD players).

-- 
Chris Caudle





More information about the time-nuts mailing list