We study the effective second-harmonic generation (SHG) susceptibility in graded metallic films by invoking the local field effects exactly and further numerically demonstrate that graded metallic films can serve as a novel optical material for producing a broad structure in both the linear and the SHG response and an enhancement in the SHG signal.

We demonstrate control of the collective motion of an optical vortex array using an electromagnetically induced transparency media. Scanning the frequency detuning between the pump and probe fields changes the susceptibility of the media, producing a unique effective diffraction of the vortex array for each detuning. We measure several experimental configurations and compare them to numerical s...

Silicon integrated optics has emerged as an attractive technology for realizing passive devices because of the efficient silicon-on-insulator sSOId guiding structures and foundry compatible processing technology. However, silicon is generally perceived to be devoid of active optical properties that are needed to realize more sophisticated optical functions such as, amplification and wavelength ...

Quasi-permanent light-induced second-order susceptibility x s2d of octupolar molecules is demonstrated. The octupolar molecule Ethyl Violet was oriented in a solgel matrix by a purely optical poling technique. The method consists of a seeding process based on a nonclassical holographic process with coherent two-frequency mixing. The growth of the induced x s2d is monitored in real time by frequ...

We demonstrate second order optical nonlinearity in a silicon architecture through heterogeneous integration of single-crystalline gallium nitride (GaN) on silicon (100) substrates. By engineering GaN microrings for dual resonance around 1560 nm and 780 nm, we achieve efficient, tunable second harmonic generation at 780 nm. The χ2 nonlinear susceptibility is measured to be as high as 16 ± 7 pm/...

We present an analytical theory for the nonlinear optical response of a strongly interacting Rydberg gas under conditions of electromagnetically induced transparency. Simple formulas for the third-order optical susceptibility are derived and shown to be in excellent agreement with recent experiments. The obtained expressions reveal strong nonlinearities, which in addition are of highly nonlocal...

We present the first study of nonlinear optical third-harmonic generation (THG) in the strongly correlated charge-transfer insulator Sr(2)CuO(2)Cl(2). For fundamental excitation in the near infrared, the THG spectrum reveals a strongly resonant response for photon energies near 0.7 eV. Polarization analysis reveals this novel resonance to be only partially accounted for by three-photon excitati...

We describe a procedure to take into account the spatial dispersion of the optical excitations in the susceptibility sum rules. We show that this implies that relativistic corrections of the same order must be considered. The final result is a decrease of the total oscillator strength equal to the ratio of the average electron kinetic energy with mc. We propose experiments with synchrotron radi...

A new third order nonlinear optical single crystal of 2-phenylbenzimidazolium-ptoulenesulphonate (PBITS) was grown by the solvent evaporation technique using methanol as a solvent. The single crystal XRD analysis reveals that crystals belong to the triclinic system. An NMR and FTIR study confirms the formation and vibrational analysis present in the compound. UV-Vis absorption studies were also...

aspergillus terreus is emerging as an etiologic agent of invasive aspergillosis among patients undergoing cancer chemotherapy, haematopoetic stem-cell transplantation, or solid organ transplantation worldwide. infections caused by aspergillus terreus has become important due to less susceptibility to antifungal drags, resistant to amphotericin b and therefore, poor clinical outcome and higher m...