  Strongly squeezed light at telecommunication wavelengths is the necessary
resource for one-sided device-independent quantum key distribution via fibre
networks. Reducing the optical pump power that is required for its generation
will advance this quantum technology towards efficient out-of-laboratory
operation. Here, we investigate the second-harmonic pump power requirement for
parametric generation of continuous-wave squeezed vacuum states at 1550nm in a
state-of-the-art doubly-resonant standing-wave PPKTP cavity setup. We use
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 observe a squeeze factor of 13dB at 1550nm from
just 12mW external pump power at 775nm. We anticipate that optimizing the
cavity coupler reflectivity will reduce the external pump power to 3mW, without
reducing the squeeze factor.
