Squeezed Vacuum Generator (2D): Degenerate Optical Parametric Oscillator

This simulator renders a 2D top-down view of a degenerate optical parametric oscillator: a pump beam at frequency 2ω drives a nonlinear crystal inside a two-mirror cavity on the left, and pairs of signal photons at ω build up inside it. On the right, rather than a classical light wave, the signal field's quantum fluctuations are drawn as a live, pannable and zoomable point cloud in phase space — a perfect circle at zero pump, stretching into an ellipse as pump power approaches threshold, with one quadrature squeezed below the vacuum shot-noise limit and the conjugate quadrature correspondingly noisier. Pump power, cavity detuning, cavity linewidth and the homodyne local-oscillator angle are all live controls, with the squeezed/anti-squeezed noise levels and intracavity photon number read out in real time from the sub-threshold OPO input-output theory formulas — corrected here to square the quadrature-variance ratio, matching the standard Collett–Gardiner result.