[time-nuts] Rubidium standard

[Bruce Griffiths]

Bruce Griffiths wrote:
> Poul-Henning Kamp wrote:
>> In message<4B0B0ED6.3080100 at xtra.co.nz>, Bruce Griffiths writes:
>>
>>> This lamp wear out mechanism is avoided if one uses laser interrogation
>>> of the absorption cell.
>> About that...
>>
>> Isn't that the sort of experiement we should try to lure Tom into 
>> doing ?
>>
>> There must be a way to create a DIY conversion of old Rb's to laser...
>>
>> Poul-Henning
>>
> As in:
> http://tf.nist.gov/timefreq/general/pdf/2232.pdf
>
> Which uses injection locking to avoid generating the 6.834...GHz 
> signal directly
>
> Bruce
Another method which may be more directly applicable when attempting to 
resuse some of the electronics in an rubidium standard whose rubidium 
lamp has failed:

http://physweb.bgu.ac.il/SUBMISSIONS/PROJECTS/Liorne_Benh_2008A.pdf

Note that one needs to use 2 rubidium 87 cells, one to lock the laser to 
the required transition, and the other to lock the microwave source to 
the Rb87 hyperfine transition.
Also one needs to use a tunable laser (ECDL-external cavity laser).
Although angle cleaved laser chips are best it is actually possible to 
construct a satisfactory ECDL with an inexpensive diode laser without 
anti-reflection coatings or angle cleaved facets.

Bruce