Homodyne and heterodyne readout
A phase-referenced local oscillator converts optical field quadratures into electrical signals.
$$X_\theta=(ae^{-i\theta}+a^\dagger e^{i\theta})/2$$
Physical intuition
A phase-referenced local oscillator converts optical field quadratures into electrical signals.
Deep dive: physical mechanism
Homodyne accesses one quadrature; heterodyne estimates both with additional measurement noise.
What is measured experimentally?
Quadrature histograms reveal displacement and squeezing.
Assumptions, noise and limitations
Mode matching and detector inefficiency affect calibration.
Research and simulation exercise
Reconstruct a Gaussian optical state from synthetic quadrature samples.
Connect the ideas
Explore the chapter overview, learning path, and references.