[time-nuts] Thinking outside the box a super reference

Bruce Griffiths bruce.griffiths at xtra.co.nz
Fri Nov 4 18:41:56 EDT 2016

Hej Magnus
A quarter waveplate doesn't depolarise, it can however convert a linearly polarised beam to a circularly polarised one.If you really need to depolarise a laser beam, scattering from a colloidal suspension of Titanium dioxide is very effective.There are no macroscopic moving parts.Brownian motion of the colloidal partticels suffices.

    On Saturday, 5 November 2016 11:28 AM, Magnus Danielson <magnus at rubidium.dyndns.org> wrote:


On 11/04/2016 10:27 PM, Poul-Henning Kamp wrote:
> --------
> In message <2af27ebe-9200-c348-c89b-b98f9c973974 at karlquist.com>, "Richard (Rick) Karlquist" w
> rites:
>> Also, one of the Rb isotopes is slightly radioactive.
>> 35 years ago, the guy in the next cubicle got away with
>> storing it under his desk.  He also happily smoked
>> cigarettes all day at his desk.  Another ERA.
> Rb87 has a halflife north of the age of the planet as far
> as I recall, and the result is a beta which goes nowhere
> far and Sr87 which is stable.

With a half-life of 49.2 Gigayears compared to universe life around 13.8 
Gigayears and the beta-decay within both glas and metal enclosure, I'm 
not overly concerned. For all practical purposes it is essentially stable.

> He got a lot more ionizing radiation from his cigaretess than he
> ever got from the Rb87.
> Just for the heck of it, I'd go laser instead of the old UHF lamp.

The 780 nm laserdiodes isn't all that hard to get, in fact I've got some 
lying around. Depolarizing needed with a quarter-wave needed not to get 
a Stark-pull.

> With respect to precision machining, that space has changed a lot
> over the last five years, with precision CNC machines, factory
> or home-built, dropping dramatically in price.

You need to tune it regardless.

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