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FMCG/Data Acquisition with LabVIEW Software: Difference between revisions
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FMCG/Data Acquisition with LabVIEW Software (view source)
Revision as of 19:36, 26 August 2016
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## Turning off the pump beam (almost completely) disables the device's sensitivity to magnetic fields. The noise collected during a measurement with the pump beam off is indicative of the '''technical noise''' (or '''probe noise''', since much of thise noise is due to polarization or intensity fluctuations in the probe beam) in the system.
## Turning off the probe beam leaves only noise produced in the electronics of the system. Generally a battery of 3 runs '''Magnetic Noise''', '''Probe Noise''', and '''Electronic Noise''' is taken to compare the levels of each.
=Z-mode=
The setup and data acquisition for Z-mode is a little more involved, though not terribly so. Generally I do all of my field nulling and optimization in DC-SERF mode. Only small adjustments are then required to get Z-mode up and running. The process is aided by a "test" LabVIEW VI which allows one to play with the Z-mode parameters to optimize. All of the following will assume the magnetometer(s) are properly nulled and the laser powers and detunings are optimized.
# Since Z-mode will involve applying a 1 kHz modulation to the atoms, and then using the LabVIEW code to demodulate that signal, it's necessary that there not be any low pass filters below 1 kHz between the photodiodes and the input to the ADC on the FPGA. It's likely that a ~300 Hz low pass filter was applied to data being taken
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