We investigate the changes in the optical properties of fused silica exposed to intense infrared femtosecond pulses. The laser-induced absorption spectrum reveals the creation of color centers inside the glass matrix, comparable with those observed in ultraviolet-exposed fused silica. The laser-induced absorption is associated with a laser-induced refractive-index change, which can be used for ...

We show that, when fundamental optical beams are present in a noncentrosymmetric medium simultaneously with their sum-frequency beam, quantum interference between singleand two-photon transitions modifies the net absorption, if the sum frequency corresponds to an energy greater than the band gap. At a macroscopic level this effect can be related to the imaginary part of a second-order susceptib...

We present a brief overview of different methods for simultaneous phase-matching of several parametric optical processes (the so-called multistep cascading) in engineered structures with the modulated second-order nonlinear susceptibility. In particular, we discuss the possibility of double phase-matching in both uniform and non-uniform quasi-phase-matched (QPM) periodic optical superlattices a...

A review of recent progress in the field of strained silicon photonics is presented. The application of strain to waveguide and photonic crystal structures can be used to alter the linear and nonlinear optical properties of these devices. Here, methods for the fabrication of strained devices are summarized and recent examples of linear and nonlinear optical devices are discussed. Furthermore, t...

2014 Optical nonlinear properties of semiconducting organic polymers with one dimensional 03C0 electron system are described. The third order nonlinear susceptibility of these polymers is specially high (#10-10 esu) and their time response very short (~ 1 ps ). Three and two photon resonances due to even and odd parity excited states are observed by third harmonic generation (THG) and by electr...

We review dispersion relations, which relate the real part of the optical susceptibility (refraction) to the imaginary part (absorption). We derive and discuss these relations as applied to nonlinear optical systems. It is shown that in the nonlinear case, for self-action effects the correct form for such dispersion relations is nondegenerate, i.e. it is necessary to use multiple frequency argu...

Within the context of the Maxwell Garnett model, we calculate the nonlinear susceptibility of a composite optical material comprised of spherical inclusion particles contained within a host material. We allow both constituents to respond nonlinearly and to exhibit linear absorption. Our treatment takes complete account of the tensor nature of the nonlinear interaction, under the assumption that...

We provide the first account of the second-order susceptibility of quartz down to 10 mum (1000 cm(-1)) and show how this data may be used along with the sum-frequency response of an amorphous gold surface to elucidate the nonlinear susceptibility of any material in the mid-infrared region. Crystalline quartz is an established material for use in second-harmonic and sum-frequency generation stud...

The main purpose of the work is to clarify the physical mechanisms which leads to the specific spectrums of the structures [1-3]. The work is based on the ideas of the effective susceptibility. The effective susceptibility of cone-shaped nanohills located at the semiconductor surface is obtained in the frame of local-field approach. The knowledge of the effective susceptibility allows to calcul...

objective: bioactive glass 45s5 is a surface reactive glass-ceramic biomaterial, developed in 1969. bag 45s5 with particle size of 20-60 nm has the ability of bone regeneration, broad spectrum antibacterial effect, repairs and replaces diseased or damaged bone. the aim of this study was to evaluate the antibacterial activity and determine mic and mbc values of nano-bag45s5 on streptococcus muta...