Kerr noise reduction and squeezing

We introduce a model of squeezing and noise reduction in the Ken effect that accounts for noise in all quadratures of the driving field. Consequently we show that Ken squeezing is much more sensitive to driving noise than squeezing produced by second harmonic generation (SHG). We experimentally demonstrate this sensitivity using a nonlinear system that tunes between strong classical SHG and Ken behaviours. Whilst the system experiences strong squeezing in the SHG limit, it experiences no squeezing in the Ken limit, although it does experience strong classical noise reduction, or 'classical squeezing'.