Some quantum information protocols require delay or storage of quantum light states so that the timing of the transaction can be controlled. One potential method for the delay and storage of quantum light states is to engineer a coherent interaction with an atomic level scheme, such as electromagnetically induced transparency [1] or addressing of coherent spin states of atomic ensembles [2]. Before such experiments can be attempted one requires a source of quantum light states at a compatible atomic wavelength. In this experiment we use periodically poled potassium titanyl phosphate (PPKTP) as the nonlinear crystal in an optical parametric oscillator (OPO) for the generation of squeezed light on the D1 line of rubidium which lies at 795 nm. Although OPOs have long been used as sources of squeezed light, the shorter wavelengths required for atomic interactions have always been a challenge due to a limited choice of nonlinear crystals. PPKTP is a new material that has recently been shown to be highly effective over a very wide range of optical frequencies [3].
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