  We present experimental studies on the generation of pulsed and
continuous-wave squeezed vacuum via nonlinear rotation of the polarization
ellipse in a $^{87}$Rb vapor. Squeezing is observed for a wide range of input
powers and pump detunings on the D1 line, while only excess noise is present on
the D2 line. The maximum continuous-wave squeezing observed is -$ 1.4 \pm0.1$
dB (-2.0 dB corrected for losses). We measure -1.1 dB squeezing at the
resonance frequency of the $^{85}$Rb $F=3 \to F'$ transition, which may allow
the storage of squeezed light generated by $^{87}$Rb in a $^{85}$Rb quantum
memory. Using a pulsed pump, pulsed squeezed light with -1 dB of squeezing for
200 ns pulse widths is observed at 1 MHz repetition rate.
