Generation of pulsed and continuous-wave squeezed light with $^{87}$Rb vapor

TL;DR

This paper demonstrates the generation of pulsed and continuous-wave squeezed vacuum light using a $^{87}$Rb vapor, achieving notable squeezing levels suitable for quantum memory applications.

Contribution

It reports the first experimental realization of both pulsed and CW squeezed light via nonlinear polarization rotation in $^{87}$Rb vapor, with detailed analysis of squeezing under various conditions.

Findings

Maximum CW squeezing of -1.4 dB observed.

Pulsed squeezed light of -1 dB for 200 ns pulses at 1 MHz.

Squeezing at the $^{85}$Rb F=3 transition resonance.

Abstract

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.