All-atomic source of squeezed vacuum with full pulse-shape control

We report on the generation of pulses of a low-frequency squeezed vacuum with noise suppression >2 dB below the standard quantum limit in a hot resonant 87 Rb vapor with polarization self-rotation. We demonstrate the possibility to precisely control the temporal profile of the squeezed noise quadrature by applying a calibrated longitudinal magnetic field, without degrading the maximum amount of squeezing