Optical nonlinearity of ionic crystals and its increasing absorption optical bistability

Abstract

This paper presents an approach to the intracavity interaction of electromagnetic waves with anharmonic lattice vibrations of ionic crystals. The nonlinear lattice dynamics and an expression for the nonlinear polarization are derived in terms of optical phonon modes. In the rotating-wave approximation the total coherent Hamiltonian of the system is derived. Using the corresponding equation of steady states, the increasing absorption optical bistability (IAOB), as a nonlinear effect, is demonstrated. The results show that optical nonlinearities due to the interaction of photons with various elementary excitations of bosonic type such as phonons and excitons may be the origin of IAOB, which is consistent with our previous works.

Cyclotron resonance of interface magnetopolarons at finite temperatures

“…where V im (z) is the image-potential energy of the electron, which is given in the second term of equation 3. For simplicity, we take into account only the lowest subband of H ⊥ , so the relevant variational wavefunction with the variational parameter ξ n can be selected as [20] φ n (z) = 2ξ 3/2 n exp(−ξ n z)…”

“…The method of calculating the self-energy of the polaron is similar to that of our previous paper [20], and is not repeated here for the sake of conciseness.…”

“…In this case, it suffices to calculate the contributions to the electron proper self-energy part by retaining the lowest-order skeleton diagram. Using the standard Green's function method [20], the total proper self-energy part of electron is given by…”

“…For simplicity, we take into account only the lowest subband of H ⊥ , so the relevant variational wavefunction with the variational parameter ξ n can be selected as [20] φ n (z) = 2ξ 3/2 n exp(−ξ n z) (…”

“…However, even in investigations of the heterostructures, only electron-BO phonon interaction was considered and electroninterface optical (IO) phonon interaction was neglected (see for instance references [2,15], and [17]). Recently, it was reported that, in obtaining the potential induced by the electronphonon interaction, IO phonons must be considered together with BO phonons in quasitwo-dimensional (Q2D) systems, especially when the distance between the electron and the interface (or surface) is comparable to the radius of the polaron [19][20][21].…”