Quantization of waves in dispersive media with application to nonlinear interactions of plasmons

Waves in a general dispersive medium represented by a quadratic or bilinear Lagrangian are quantized. A phenomenological method is used leading to medium excitations in terms of quasiparticles (bosons) which are photon-like, phonon-like etc. The possibility for negative energy excitations is considered and interactions between different wave types studied. The simplicity of the analysis is demonstrated by an analysis of nonlinear interactions in a multistream medium of plasmons.