Third-harmonic generation in a general two-component quasi-periodic optical superlattice.
ABSTRACT The quasi-periodic optical superlattice is a promising material for use in optical frequency conversion. We propose a method for designing a quasi-periodic structure for efficient third-harmonic generation (THG) at any given wavelength. With this method we have made a LiTaO(3) sample in which 27% THG at 0.48microm was achieved, together with a series of highly efficient multiwavelength second-harmonic generation outputs. The result is in good agreement with the theoretical prediction.
Article: High-flux photon-pair source from electrically induced parametric down conversion after second-harmonic generation in single optical superlattice.[show abstract] [hide abstract]
ABSTRACT: We present here a possible high-flux photon-pair source constructed by single lithium niobate optical superlattice (OSL) with a combined quasi-periodically and periodically poled structure, which is from the principle of electrically induced parametric down conversion (PDC) after second-harmonic generation (SHG), predicted by the united theory developed in this paper, in which SHG, PDC and electro-optic (EO) effect are comparably treated as two-order nonlinear effects. In the OSL, the e-polarized fundamental frequency photons are first converted to double frequency ones with the same polarization; then the PDC process is triggered by EO effect when the fundamental frequency photons are almost exhausted; finally, the double frequency photons are converted again to a series of two-photon pair of fundamental wave. It is demonstrated that at 100 degrees C, in a 20.2mm long OSL with a 30V / mm applied electric field, a 100MW/cm(2), 1080 nm laser beam can be translated to a flux of high-purity two-photon pairs with a conversion efficiency close to 100%; and for a longer OSL the pump intensity can be further lowered. The device can also act as an ultra-low field electro-optic switch.Optics Express 07/2007; 15(13):8275-83. · 3.59 Impact Factor