Second harmonic generation in the moving media

TL;DR

This paper explores how moving media can induce second harmonic generation in diamond, a material lacking intrinsic second-order susceptibility, by using electric fields and quasi-phase matching to optimize the process.

Contribution

It introduces a novel method of inducing second harmonic generation in non-linear media through moving susceptibility and applies spatiotemporal QPM for optimization.

Findings

Induced second harmonic appears at shifted frequencies around 2ω₀.

Electric field can generate effective second-order susceptibility in diamond.

Numerical results confirm the feasibility of the proposed method.

Abstract

Because of the importance of second harmonic generation in some nonlinear media, in this paper, we investigated induced second harmonic generation in diamond where there is no intrinsic second order susceptibility, X(2). The electric field is proposed to introduce moving susceptibility of the second order and induce second harmonic generation. Then, spatiotemporal (QPM) is applied to optimize the induced second harmonic generation. Numerical results reveals that in this way, the induced second harmonic is found at the frequency of omega (2) = 2 omega(0) + or - Delta omega rather than omega (0).