Squeezed light for bandwidth limited atom optics experiments at the Rubidium D1 line

Abstract

We report on the generation of more than 5 dB of vacuum squeezed light at the Rubidium D1 line (795 nm) using periodically poled KTiOPO$_{4}$ (PPKTP) in an optical parametric oscillator. We demonstrate squeezing at low sideband frequencies, making this source of non-classical light compatible with bandwidth limited atom optics experiments. When PPKTP is operated as a parametric amplifier, we show a noise reduction of 4 dB stably locked within the 150 kHz-500 kHz frequency range. This matches the bandwidth of Electromagnetically Induced Transparency (EIT) in Rubidium hot vapour cells under the condition of large information delay.