Fig. 6: Frequency sweep and conversion bandwidth.
a The Doppler-broadened transmission spectrum of a reference rubidium vapor cell (outside the microwave cavity) at room temperature, measured while sweeping the pump laser frequency. The dotted line shows a transmission model curve with good agreement to the measured trace. This trace was taken simultaneous to the data shown in Fig. 3b; the positions of the two Doppler peaks are used to calibrate the horizontal frequency scale. b The raw generated signal during a scan of δI, as measured with a vector network analyzer (VNA) in S21 mode. We measure a conversion bandwidth (FWHM) of 910(20) kHz when the laser is locked on-resonance and with a z-magnetic field of 209 mG. The dashed line is a smoothing spline used to determine the bandwidth. No generation is visible when the laser is off-resonance. The cavity resonance has a FWHM of 417 kHz, as measured with the VNA in S11 mode.
