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

We report on the generation of more than 5 dB of vacuum squeezed light at the rubidium D1 line ( 795 nm) using periodically poled KTiOPO4 (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.