For a rubidium vpour standard a cavity is essential, one could always use a microwave horn to illuminate the cell in an anechoic chamber. Using an integrating sphere can enhance the contrast of the optical signal significantly.
http://www.princeton.edu/physics/graduate-program/theses/theses-from-2011-1/bmcguyer_dissertation.pdf https://infoscience.epfl.ch/record/178228/files/IFCS_Invited_Talk_Finalpdf.pdf https://doc.rero.ch/record/32317/files/00002318.pdf http://tf.nist.gov/general/pdf/1154.pdf http://tf.boulder.nist.gov/general/pdf/1663.pdf Bruce On Sunday, January 08, 2017 10:20:33 PM Bruce Griffiths wrote: > Possible sources of Rubium vapour > cells:https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=1470 > > http://www.precisionglassblowing.com/custom-solutions/optical-glassware/vapo > r-wavelength-reference-cells/ > > https://www.sacher-laser.com/home/lab-equipment/spectroscopy/reference_gas_a > nd_vapor_cells/reference_gas_and_vapor_cells.html > > > Bruce > > On Monday, 9 January 2017 11:14 AM, Bruce Griffiths > <bruce.griffi...@xtra.co.nz> wrote: > > > Bob > As long as one stays away from CPT and merely uses the laser as a > replacement for the traditional rubidium lamp plus filters it should be > easy enough as one doesnt need to modulate the laser at 3.4 GHz.I was > thinking something along the lines of the recent PhD thesis that gave all > the detail required to duplicate their low noise rubidium standard that was > quieter than am HP5065.One could easily substitute ones own ECDL (These can > easily be constructed from commercially available parts) and improve > somewhat on the performance (The oven design of most commercial ECDLs seems > suboptimal). Bruce > > On Monday, 9 January 2017 10:23 AM, Bob Camp <kb...@n1k.org> wrote: > > > Hi > > The large diameter Rb cells are a bit harder to come by than the more > generic telecom sized cells. I suspect you are correct and they are out > there from somebody.. The real advantage you would have with an Rb is that > the design you do is gigantic compared to what everybody is doing today. > Their constraints are not your constraints. > > Based on the laser driven Rb on my bench …. don’t bother with that part of > it. It is indeed doable. Doing it in a fashion that gives you a better > standard …. not really easy at all. > > Bob > > > On Jan 8, 2017, at 3:55 PM, Bruce Griffiths <bruce.griffi...@xtra.co.nz> > > wrote: > > > > The rubidium standard appears much more manageable given that the cavity > > dimensions are somewhat more compact and rubidium vapour cells are > > readily available. Substituting a laser for the lamp should also help in > > improving the reliability. However an ECDL laser locked to a rubidium > > line is required for a double resonance setup. Building ones own ECDL > > doesn't appear to be particularly daunting, however low noise drive > > electronics will be required. All the necessary optics are off the shelf > > items. One still has the issue of the frequency pulling due to the > > presence of the vapour cell. Bruce > > > > On Sunday, January 08, 2017 10:22:54 AM you wrote: > > > Hi > > > > > > I guess the question then would be: > > > > > > Is a H Maser that runs 6.6 x 10^-12 at 1 second worth the trouble? > > > > > > With 100 KHz / C temperature coefficients running around, getting > > > good stability in a real world setting at 1 day will be “interesting”. > > > > > > Just for reference: The MH-2010 data sheet shows 1.5x10^-13 at > > > 1 second for the “cheap” version and 8x10^-14 at one second for > > > the low noise version. Data showing the 5065 Rb at 1x10^-12 at > > > 1 second is running around on various web sites. > > > > > > The NIST paper suggests that they made several prototypes before > > > they got one good one working. That’s a lot of “fun and games” with > > > ceramic machine lathes and Rb magnetometers….. > > > > > > The punch line being - would the same effort / cost / many years of time > > > be > > > more fruitful (ADEV wise) doing a large package Rb (like a 5065) ? > > > Based > > > on the number of people making them in volume over the years, Rb’s > > > appear > > > to be the easier item to debug, design, and build. > > > > > > Bob > > > > > > > On Jan 8, 2017, at 6:01 AM, Bruce Griffiths > > > > <bruce.griffi...@xtra.co.nz> > > > > wrote: > > > > > > > > You could try a cavity like the one > > > > in;http://tf.nist.gov/general/pdf/156.pdf > > > > > > > > This avoids the requirement for a fused quartz storage bulb. > > > > Bruce > > > > > > > > On Sunday, 8 January 2017 11:33 PM, timeok <tim...@timeok.it> wrote: > > > > Hi, > > > > the thought of being able to work on building a H Maser has always > > > > accompanied me in recent years. I fully understand the many > > > > difficulties > > > > of this project and also the necessity of a work team. Maybe a Passive > > > > Maser would be easiest to implement, but I do not know in detail the > > > > processes of construction of the physical part of the interrogation. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.