Adjustable Propagation Length Enhancement of the Surface Plasmon Polariton Wave via Phase Sensitive Optical Parametric Amplification

Mohammad Amin Izadi,Rahman Nouroozi

doi:10.1038/s41598-018-33831-y

Abstract

The adjustable propagation length enhancement of the surface plasmon polariton (SPP) mode under the effects of the initial relative phase (ψ0) between interacting waves in difference frequency generation (DFG) based optical parametric amplification (OPA) are numerically considered. The waveguide is a silver coated PPLN planar waveguide. Obtained results indicate ultra long propagation length for the SPP mode could be achieved via manipulation of ψ0 in exact quasi phase matching (QPM) case up to 30 mm for initial pump intensity about 66 MW/cm for degenerate DFG (dDFG). For chirped QPM by mitigating the high depletion of the pump intensity, it is possible to enhance the SPP propagation length up to 43 mm for initial pump intensity about 135 MW/cm. In this case ψ0 does not affect the SPP propagation length except around a narrow range of unsuitable phases. The unsuitable phase is frac{pi }{2} for exact QPM but is pump dependent for chirped QPM case. Using this unsuitable phase is the key parameter to the SPP propagation length enhancement via controlling ψ0. In this case with a high pump intensity, the pump and the SPP modes interact at longer distances which leads to the SPP propagation length enhancement.

Highlights

Like using gain media which induces extra noises[5,6], utilizing long range SPPs which enhance the SPP propagation length up to some millimeters[7,8], regenerating of SPP waves in an asymmetric waveguide structure[9] and enhancement of surface plasmon polariton propagation length by the interference with photonic modes10. 2- methods which use nonlinear interactions between a hybrid guided mode (HGM) and SPPs11
It was shown that the initial relative phase between pump and signal (ψ0) in difference frequency generation (DFG)-optical parametric amplification (OPA) interactions may affect the rate of signal amplification and idler generation[18,19]
According to this sensitivity to ψ0, DFG-OPA processes can be categorized into two major classes: In a phase insensitive (PIS) OPA, which occurs in the usual non-degenerate DFG (ndDFG) interaction, the SPP idler generation, SPP

Summary

Introduction

Like using gain media which induces extra noises[5,6] (the enhanced SPP propagation length is about 1 cm in this case), utilizing long range SPPs which enhance the SPP propagation length up to some millimeters[7,8], regenerating of SPP waves in an asymmetric waveguide structure[9] and enhancement of surface plasmon polariton propagation length by the interference with photonic modes10. 2- methods which use nonlinear interactions between a hybrid guided mode (HGM) and SPPs11. It was shown that the initial relative phase between pump and signal (ψ0) in DFG-OPA interactions may affect the rate of signal amplification and idler generation[18,19] According to this sensitivity to ψ0, DFG-OPA processes can be categorized into two major classes: In a phase insensitive (PIS) OPA, which occurs in the usual ndDFG interaction, the SPP idler generation, SPP signal/idler amplification and SPP signal/idler propagation length enhancement does not depend on ψ0. This type of amplification, except the noise figure, is similar to erbium doped and semiconductor amplifiers. PIS-ndDFG into the PS-ndDFG is to inject a wave with angular frequency of ωi at the beginning of interaction (waveguide input)

Objectives

Results

Conclusion