Modeling comparison of second-harmonic generation in high-index-contrast devices

Abstract

In this paper we model second-harmonic generation in a microphotonic structure using two different numerical methods. The proposed two-dimensional waveguide device is challenging as it incorporates a high-contrast grating, which instigates strong local enhancement but also radiation losses. The first simulation method extends the time-domain beam propagation method, whereas the second one builds upon frequency-domain eigenmode expansion. Good agreement between both tools is obtained for both the linear and nonlinear simulations

Dispersive Nonlinear MRTD for SHG Applications

“…The structure is discretised with cell size = x = z = d/8 and the adopted time step is t = 0.008 fs. Results are in agreement with what is reported in the literature [7]. Next, Figure 11.10 shows the calculated SHG efficiency after N = 20 periods in the second harmonic wavelength range.…”

“…This type of device consists practically in a 1D photonic bandgap structure and is used in the SHG process because of its ability to modify topologically the dispersion characteristic in such a way that the phase matching condition through the waveguide is achieved when the effective index of the device at the fundamental frequency is equal to the effective index at the second harmonic frequency [6,7]. This periodic structure was proposed in a modelling exercise in the COST-P11 project (http://w3.uniroma1.it/energetica/).…”