[time-nuts] Pressure sensitivity of Rb vapor cell standards

[Magnus Danielson]

Hi,

On 2020-02-18 11:06, Attila Kinali wrote:
> On Mon, 17 Feb 2020 18:16:04 -0600
> magnus <magnus at rubidium.se> wrote:
>
>> Hi,In the 5065 and most others, the light intensity is not stabilized.
>> It should not be too hard to regulate the Rb lamp amplitude and servo
>> it to light intensity from the detector. Didn't Poul-Henning check this?
>
> I still think, replacing the 5065 lamp with a 780nm LED would be worthwhile
> to try. Yes, the LEDs have a broader spectrum than a lamp, but it is a lot
> easier to keep it stable than a fluerescent lamp. It would also allow to
> lower the temperature of the Rb cell to get to the zero tempco point (which
> seems to be around 60°C for most mixtures).

Well, as I recall it one has to have a quarter-wave window to remove
polarization issues, as that too creates light-shift issues. Also, one
wants a beam-expander to optically cover more of the cavity than the
direct laser do. I have a bunch of 780 nm LED-lasers for this purpose,
but it would be fun to try even as quick-hack.

So, nothing unsolveable, but things to attend to.

Cheers,
Magnus