Non-degenerate optical parametric amplification analysis of surface plasmon polariton wave in a silver coated PPLN planar waveguide

Abstract

Propagation length enhancement of surface plasmon polariton (SPP) wave in telecom c-band through nonlinear χ(2)-based nondegenerate difference frequency generation (ndDFG) process is investigated theoretically. The SPP wave is excited in a silver coated planar periodically poled lithium niobate (PPLN) waveguide. Quasi phase matching is used to compensate the phase mismatch between the interacting excited SPP and guided modes. Domain inversion with proper domain wavelength of Λ = 101.9 μm leads to nonlinear efficient mode interaction of guided↔SPP. With 31 MW/cm coupled pump intensity a SPP amplification of about 16 dB is achievable which results in enhancement of the propagation length about 11 mm. The acceptance SPP amplification bandwidth is pump power dependent. In a low pump depletion regime, a 3-dB bandwidth is about 75 nm whereas in more depletion the bandwidth becomes narrower but not less than 25 nm.