I have recently come across two key concepts in quantum optics: shot noise and back-action noise. This is very important for me to know: first, are shot noise and back-action noise the same? Please let me know if there is any other equivalent term for back-action noise among the quantum optics community. I am also wondering whether back-action is the nature of light beam in vacuum, or is it related basically to measurement detector like homodyne?
I really like to know exclusively the characteristics of back-action noise to be able to model it.