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

Abstract

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.

Rubidium resonant squeezed light from a diode-pumped optical parametric oscillator

“…The single pass eective nonlinearity of PPKTP is according to literature [34,42,68] between 1%/W and 2%/W. Due to low available power (for obtaining 100 µW of blue power we would need approximately 100 mW of red light which was not available from the laser system) we did not measure the single pass nonlinearity of our crystal.…”

“…Fast development of the cesium resonant sources of nonclassical light was possible due to the wavelength of cesium D2 at 852 nm where KNbO crystals were readily available. New technology development enabled the demonstration of squeezing at the rubidium resonance [1,2,34,67]. These experiments use distinct methods: squeezing in a waveguide [1] and downconversion in an OPO [2,34,67].…”

“…New technology development enabled the demonstration of squeezing at the rubidium resonance [1,2,34,67]. These experiments use distinct methods: squeezing in a waveguide [1] and downconversion in an OPO [2,34,67]. In the latter case, squeezing at the rubidium D1 line was achieved in a subthreshold OPO using a Ti:Sapphire laser as pump and periodically poled potassium titanyl oxide phosphate (PPKTP) as nonlinear medium [67,34,2].…”

“…These experiments use distinct methods: squeezing in a waveguide [1] and downconversion in an OPO [2,34,67]. In the latter case, squeezing at the rubidium D1 line was achieved in a subthreshold OPO using a Ti:Sapphire laser as pump and periodically poled potassium titanyl oxide phosphate (PPKTP) as nonlinear medium [67,34,2]. The noise suppression of this method was shown to be more than 5 dB [34].…”

Rubidium resonant squeezed light from a diode-pumped optical-parametric oscillator

“…The single pass e ective nonlinearity of PPKTP is according to literature [34,42,68] between 1%/W and 2%/W. Due to low available power (for obtaining 100 µW of blue power we would need approximately 100 mW of red light which was not available from the laser system) we did not measure the single pass nonlinearity of our crystal.…”