We have measured the extinction and absorption cross sections of carbon particles emitted by a propane diffusion flame both in an aerosol chamber and on size-segregated samples deposited on optical windows. The absorption cross section, the single scattering albedo, and the Ångström exponent show drastic dependencies both on the C/O ratio and on the particle size. This is interpretated as being...

Results of a self-consistent ultrafast study of nonlinear optical properties of silicon nanowaveguides using heterodyne pump-probe technique are reported. The two-photon absorption coefficient and free-carrier absorption effective cross-section were determined to be 0.68cm/GW, and 1.9x10(-17) cm2, respectively and the Kerr coefficient and free-carrier-induced refractive index change 0.32x10(-13...

In this work, the synthesis and the nonlinear absorption and population dynamics investigation of a series of zinc phthalocyanines (ZnPcs) dissolved in chloroform are reported. In order to determine the relevant spectroscopic parameters, such as absorption cross-sections of singlet and triplet excited states, fluorescence relaxation times, intersystem crossing, radiative decay and internal conv...

Two-photon-induced fluorescence is observed from the photodynamic phycobiliprotein phycoerythrin. Temporal, spectral, and intensity-dependent properties of the two-photon-induced fluorescence emission from phycoerythrin excited by a 1.06-mum laser beam are reported. The measured two-photon absorption cross section of phycoerythrin is an order of magnitude larger than that of Rhodamine 6G. The p...

The vapor pressure of rubidium was determined in the neighborhood of 330 K from measurements of optical absorption of the resonance lines. A narrow-line source was used and a full analysis of the line profiles was done. Measurements of resonance-broadening depolarization give another check on the Rb vapor pressure in the 430-K range, assuming that theoretical cross section is correct. The resul...

Nonlinear optical properties of a series of newly-synthesized ladder-type chromophores containing oligo-p-phenylene moiety with different π-conjugated lengths were theoretically studied by numerically solving the rate equations and the field intensity equation with an iterative predictor-corrector finite-difference time-domain technique. Ab initio calculation results show that the compounds can...

We use wavelength tunable femtosecond pulses to measure intrinsic (simultaneous) two-photon absorption (2PA) and three-photon absorption (3PA) molecular cross section in two series of p-conjugated dendrimers built of identical 4,40-bis(diphenylamino) stilbene (BDPAS) and 4,40-bis(diphenylamino) distyrylbenzene (BDPADSB) repeat units. Record large 2PA cross sections, s2=10 46 cm s are obtained f...

The plasmonic gold nanoparticles are promising candidates for photothermal therapy (PTT) application. The optical properties of various gold nanoparticles have been widely investigated for PTT application in the first near-infrared (NIR) window (650-950 nm). However, few studies have been reported on the nanoparticles employed in the second NIR window (1000-1350 nm) where light penetrates deepe...

Colloidal nanoplatelets (NPLs) have recently emerged as favorable light-emitting materials, which also show great potential as optical gain media due to their remarkable optical properties. In this work, we systematically investigate the optical gain performance of CdSe core and CdSe/CdS core/crown NPLs having different CdS crown size with one- and two-photon absorption pumping. The core/crown ...