Observation of 13dB squeezing at 1550nm

6 June 2019

Photo: AG Schnabel

In this project we investigated the second-harmonic pump power requirement for parametric generation of continuous-wave squeezed vacuum states at 1550 nm in a state-of-the-art doubly resonant standing- wave periodically poled potassium titanyl phosphate cavity setup. We used coarse adjustment of the Gouy phase via the cavity length, together with temperature fine-tuning, for simultaneously achieving double resonance and (quasi) phase matching, and observed a squeeze factor of 13 dB at 1550 nm from just 12 mW of external pump power at 775 nm. We anticipate that optimizing the cavity coupler reflectivity will reduce the external pump power to 3 mW, without reducing the squeeze factor. For producing a spectrum of extremely pure squeezed states just 1.2 mW of pump power were necessary. The work was published here.