Second Harmonic Generation In Photonic Crystals Research Articles

Second-harmonic generation in photonic crystals with a pair of epsilon-negative and mu-negative defects

A conventional one-dimensional photonic crystal with a conjugated pair of epsilon-negative and mu-negative defects has been presented, and only the defects are presumed to possess quadratic nonlinearity. Large enhancement of second-harmonic generation is predicted in numerical simulation. Interface and volume nonlinearity are both utilized in the process of second-harmonic generation due to the strong localization of the fundamental wave.

Slow-light enhanced collinear second-harmonic generation in two-dimensional photonic crystals

We predict an enhanced efficiency of collinear second-harmonic generation in photonic crystals. This can be achieved by taking advantage of the complexity of the dispersion relation in periodic lattices. Thus, two essential conditions for increasing the nonlinear interaction, namely, phase matching and small group velocity (slow light), can be met simultaneously. The analytical results based on a modal approach are verified with rigorous simulations by means of the finite-difference time-domain method. The influence of material dispersion on optimal phase match is discussed.

Giant third-harmonic in porous silicon photonic crystals and microcavities

In recent years, the nonlinear optics of photoniccrystals (PCs) and PC-based microcavities (MCs) hasbeen progressing intensively [1]. Giant nonlinear-opti-cal phenomena caused by giant effective dispersion atthe edges of the photonic band gap and in the vicinityof the cavity mode, and also by the enhancement ofoptical fields inside PCs and MCs under optimal fre-quency–angular conditions, can be observed in suchmicrostructures. In particular, multiple reflection inter-ference in PCs can compensate the phase mismatch forfundamental and second-harmonic waves when one ofthe waves falls on the edge of the photonic band gap inthe space of frequencies or wave vectors [2]. Such aneffective fulfillment of the phase matching conditionsleads to a resonant enhancement of second-harmonicgeneration in PCs composed, for example, of dielectricpolystyrene spheres [3], alternate GaAs–AlGaAs [4] orZnS–SrF

Conversion efficiency for second-harmonic generation in photonic crystals

We derive an analytical expression for the conversion efficiency of second-harmonic generation (SHG) in a photonic crystal. The results obtained for the undepleted-pump limit allow us to describe the role played by the feedback and dispersion introduced by the photonic crystal and hence to optimize the SHG process.