With a longish BNC-cable between a PDA-output and a 4 GHz oscilloscope we see a 10%-to-90% rise-time of <700 ps.
Pulse distribution amplifier rise-time measurement
Month: December 2019
clock-transition scan at 128x speedup
Recorded at 2x speed with OBS from the youtube live-stream, then converted to MP4 with VLC, then run twice through Garmin Virb Edit producing 8x speedup both times.
88Sr+ clock transition in a low magnetic field
We've completed a second magnetic shielding layer, based on the same plywood+METGLAS concept as the first shield. This should further shield the 88Sr+ ion from unwanted magnetic field fluctuations. To further reduce the DC-field we've now applied a counter-field using a few milliAmps of current through three coils that surround the ion trap.
When the Zeeman components are this close together (the field is <0.4 uT) it is fairly quick to scan over the components. Here we see the four innermost pairs of peaks +/-C1 through +/-C4 of the clock-transition at 445 THz (674nm red light!). One scan runs in about one hour - and will be plotted on top of the older scans. We shoot 100 pulses of the laser-light at the ion and the height of the bar shows how many times we successfully drove the ion into the dark clock-state.