Degenerate Parametric Amplification Process; A Path-Integral Approach

В. Г. Андреев, О. А. Васильева, Evgueny A. Lapshin +1 more

Mark S. Hillery, Muhammad Suhail Zubairy

Flavius Schackert, Chad T. Rigetti, Baleegh Abdo +6 more

Saeed A. Khan, A. Metelmann, Hakan E. Türeci

Fuyong Wang

It is demonstrated that the nature of optical parametric amplification is a quantum phenomenon. The system Lagrangian can be constructed by the path integral of coherent state. The equations of motion for photon operators are indeed the Euler-Lagrange equations of a Lagrangian. The quantum state evolution equation can also be obtained without resorting to quantum Hamiltonian or Lagrangian. Starting with classical Newton equation, quantum transition amplitude of the system can be educed by surface integral.

Henrik C. Pedersen, Per Michael Johansen

We present for the first time, to our knowledge, a theoretical analysis of the nonlinear dynamic space-charge field buildup when a photorefractive medium is exposed simultaneously to two running gratings. It is shown that the two gratings are nonlinearly coupled, hence, for an appropriate choice of parameters, the two gratings interact, causing one grating to be amplified at the expense of the other. This process is referred to as degenerate parametric amplification. In principle an infinite amplification is possible because, even in cases for which no signal grating (i.e., the one to be amplified) is externally seeded into the crystal, a finite signal-grating amplitude is obtained after relaxation of the amplification process.