M. G. Martemyanov

Giant microcavity enhancement of second-harmonic generation in all-silicon photonic crystals

Second-harmonic generation (SHG) spectra of single and coupled porous silicon-based photonic crystal microcavities are studied in both frequency and wave vector domains. For the fundamental field resonant to the microcavity mode the second-harmonic intensity is enhanced by 102 times in comparison with that outside the photonic band gap. SHG spectroscopy in identical microcavities coupled through the intermediate Bragg reflector reveals two SHG peaks if the fundamental field is in resonance with the splitted mode of coupled microcavities. The spatial confinement of the resonant fundamental radiation is directly probed at the microcavity cleavage by scanning near-field optical microscopy.

Giant optical second-harmonic generation in single and coupled microcavities formed from one-dimensional photonic crystals

The nonlinear optical properties of one-dimensional all-solid-state photonic-crystal microcavities (MCs) are experimentally studied by second-harmonic generation (SHG) spectroscopy in both the frequency and the wave-vector domains. The studied single and coupled MCs are formed by the alternating of mesoporous silicon layers of different porosities. When the fundamental radiation is in resonance with the MC mode the second-harmonic intensity is enhanced by a factor of approximately 102. The resonant SHG response is compared with the off-resonance response, as the fundamental wavelength is outside the photonic bandgap. The splitting of the modes of two identical coupled MCs is observed in the wave-vector domain spectrum of enhanced SHG. The SHG enhancement is attributed to the combined effects of the spatial localization of the fundamental field in the MC spacer and the fulfillment of the phase-matching conditions. The confinement of the resonant fundamental field is probed directly at the MC cleavage by a scanning near-field optical microscope. The role of the phase matching that is associated with the giant effective dispersion in the spectral vicinity of the MC mode is deduced from a comparison with the SHG peaks at both edges of the photonic bandgap.

Giant Third-Harmonic in Porous Silicon Photonic Crystals and Microcavities

A giant enhancement (no less than by 103) of the optical third-harmonic generation in one-dimensional porous silicon microcavities and photonic crystals was observed experimentally. The enhancement is due to the resonant enhancement of the fundamental field in the cavity mode and the fulfillment of the phase matching condition at the photonic band gap edges of the photonic crystal and in the vicinity of the microcavity mode.

Optical third-harmonic generation in one-dimensional photonic crystals and microcavities

The formalism of nonlinear transfer matrices is used to develop a phenomenological model of a cubic nonlinear-optical response of one-dimensional photonic crystals and microcavities. It is shown that third-harmonic generation can be resonantly enhanced by frequency-angular tuning of the fundamental wave to the photonic band-gap edges and the microcavity mode. The positions and amplitudes of third-harmonic resonances at the edges of a photonic band gap strongly depend on the value and sign of the dispersion of refractive indexes of the layers that constitute the photonic crystal. Model calculations elucidate the role played by phase matching and spatial localization of the fundamental and third-harmonic fields inside a photonic crystal as the main mechanisms of enhancement of third-harmonic generation. The experimental spectrum of third-harmonic intensity of a porous silicon microcavity agrees with the calculated results.

Optical Third-Harmonic Generation in Coupled Microcavities Based on Porous Silicon

The resonance features of the third-harmonic generation have been observed in 1D coupled microcavities consisting of three Bragg reflectors and two identical half-wave layers of mesoporous silicon. The third-harmonic intensity increases by a factor of about 103 in the resonance of fundamental radiation with each of the modes of coupled microcavities. It has been shown that the resonance positions in the angular spectra of the third-harmonic intensity depend on the coupling between microcavities that is determined by the transmission of the intermediate Bragg reflector. In the framework of the transfer-matrix method with nonlinear sources, it has been shown that the basic mechanism of the enhancement of the third-harmonic generation in coupled microcavities based on porous silicon is the constructive interference of the partial third-harmonic waves that are generated by near-surface layers.

Microcavity enhancement of nonlinear response of one-dimensional photonic crystals based on porous silicon

Summary form only given. We report on the fabrication of a specially designed porous silicon microcavity (MC) with the cavity mode located inside the photonic band gap, and on the experimental observation of the enhancement of the second-harmonic (SH) response of such microstructures in the vicinity of the MC mode.

Spectroscopy of second- and third-harmonic generation in silicon photonic crystals and microcavities

In this paper enhanced second- and third-harmonic generation (SHG and THG) is observed in one-dimensional photonic crystals and microcavities (MCs) formed from mesoporous silicon. The SHG and THG spectra measured in both frequency and wave-vector domains reveal two types of the resonant enhancement, namely, as the fundamental radiation is tuned across the photonic band gap edge and if it is in the resonance with the MC mode. The SHG and THG enhancements are observed also in coupled photonic-crystal microcavities, in which the electromagnetic interaction between coupling cavity spacers is controlled by the intermediate Bragg reflector. The eigenmodes of coupled MCs are split with spectral (angular) gap determined by the intermediate photonic crystal transmittance.

Second- and third-harmonic generation spectroscopy of coupled microcavities formed from all-silicon photonic crystals

Resonances in second- and third-harmonic spectra of two identical coupled porous silicon microcavities reveal strong dependence on parameters of separating photonic crystal.

Observation of the third-harmonic generation in one-dimensional all-silicon microcavities

The enhancement of the third-harmonic generation (THG) in photonic crystal microcavities fabricated from alternating layers of mesoporous silicon is experimentally studied. Two types of THG resonances are observed in the third-harmonic intensity spectra measured in both angular and frequency domains. The THG enhancement is obtained as the fundamental radiation is in the resonance with the cavity mode and is attributed to the spatial localization of the fundamental field inside the cavity spacer and the fulfillment of the phase-matching conditions for THG. The intensive THG response is also observed as the fundamental radiation is tuned across the photonic band gap edge and is supposed to be attributed to the THG phase-matching. Additional factor for the THG enhancement is the three-photon resonance of the porous silicon cubic susceptibility.

Split-mode-enhanced second-harmonic generation in porous silicon-coupled microcavities

The enhancement of the second-harmonic generation (SHG) in all-silicon coupled microcavities (CMC) based on one-dimensional photonic crystals is experimentally studied. CMC are fabricated from alternating layers of electrochemically grown mesoporous silicon and consist of two identical half-wavelength-thick cavity spacers separated by additional porous silicon photonic crystal. The enhancement of the second-harmonic response of CMC in the vicinity of splitted cavity modes is experimentally observed in both angular (wave vector) and frequency domain spectra. The variation of transmission of the intermediate photonic crystal, which controls the interaction between coupled cavity spacers, leads to monotonic dependence of the SHG resonances splitting on the number of pairs of the intermediate Bragg reflector.