We propose and analyze a scheme for tunable coherent perfect absorption (CPA) near-perfect reflection (near CPR) in three-level $\mathrm{\ensuremath{\Lambda}}$-type atom-cavity system. With electromagnetically-induced-transparency-type interference induced by coupling laser, it provides method of near CPR at two-photon resonance. By virtue different strengths, CPA can be tuned from the linear r...

Theory of optical absorption linearly and circularly polarized light in surface edge states topological insulators is developed for a nonlinear intensity regime. The absorbance the width both decrease as $1/\sqrt{I}$ at high $I$. Elastic scattering photoexcited electrons holes taken into account. bleaching shown to be strongly suppressed by elastic scattering. linear-circular dichroism one- two...

The nonlinear optical properties of four metallic (Au-, Au/Ag-, Ag-, and Pt-) nanoparticle suspensions in toluene have been studied in both femtosecond and nanosecond regimes. Nonlinear transmission measurements in the femtosecond laser regime revealed two-photon absorption (2PA) induced nonlinear attenuation, while in the nanosecond laser regime a stronger nonlinear attenuation is due to both ...

A dramatic enhancement of the thermally induced nonlinear optical response in compositionally heterogeneous plasmonic trimers is reported. It is demonstrated numerically that the nonlinear absorption performance of silver nanoparticle dimers under pulsed illumination can be enhanced by more than two orders of magnitude through the addition of only 0.1 vol. % of gold in the dimer gap. The nonlin...

We report on the investigation of the nonlinear optical properties of castor oil using the Z-scan technique. Nonlinear refraction and absorption measurements were performed for two different laser wavelengths, 514 and 810 nm, in the CW regime, and for 810 nm in femtosecond regime. The CW results showed that castor oil has a large negative nonlinear refractive index n2 = -3.2 x 10 cm/W for the l...

Photoacoustic (PA) detection of single absorbing targets such as nanoparticles or cells can be limited by absorption background. We show here that this problem can be overcome by using the nonlinear photoacoustics based on the differences in PA signal dependences on the laser energy from targets and background. Among different nonlinear phenomena, we focused on laser generation of nanobubbles a...

We propose high index contrast InGaP photonic wires as a platform for the integration of nonlinear optical functions in the telecom wavelength window. We characterize the linear and nonlinear properties of these waveguide structures. Waveguides with a linear loss of 12 dB/cm and which are coupled to a single mode fiber through gratings with a -7.5 dB coupling loss are realized. From four wave m...

We present a new laser system and nonlinear microscope, designed for differential nonlinear microscopy. The microscope features time-correlated single photon counting of multiphoton fluorescence generated by an alternating pulse-train of orthogonally polarized pulses. The generated nonlinear signal is separated using home-built electronics. Results are presented on fluorescence-detected nonline...

Polymethine dyes (PDs) with absorption bands in the near-infrared region undergo symmetry breaking in polar solvents. To investigate how symmetry breaking affects nonlinear optical responses of PDs, an extensive and challenging experimental characterization of a cationic 2-azaazulene polymethine dye, including linear absorption, fluorescence, two-photon absorption and excited-state absorption, ...

NONLINEAR OPTICAL PROPERTIES OF NOVEL NANOSTRUCTURED ION IMPLANTED AND LASER ABLATED SILICON USING FEMTOSECOND PULSE EXCITATION by Elaine N. Lalanne The study of the nonlinear optical properties of novel nanostructured ion implanted and laser ablation of Silicon is motivated by the need for materials that exhibit large values of the real part of the third order nonlinear susceptibility (x (3)Re...