Quantum electrodynamics and quantum optics

What is optomechanical Hamiltonian? How does linearization work and how to justify it?

What is the quantum backaction force on the mechanical oscillator?

What is the physical mechanism that enables optical squeezing?

What are the Fourier domain operators? What are their commutation relations and statistical properties?

What is the physically the optical cavity and the mechanical oscillator? 

What is the technical difficulties in observing large optical squeezing?

How is different optical quadrature spectrum measured?

What is the typical bandwidth in observing this type of optical squeezing?