Enhancement of bulk second-harmonic generation from silicon nitride films by material composition

We present a comprehensive tensorial characterization of second-harmonic generation from silicon nitride films with varying composition. The samples were fabricated using plasma-enhanced chemical vapor deposition, and the material composition was varied by the reactive gas mixture in the process. We found a six-fold enhancement between the lowest and highest second-order susceptibility, with the highest value of approximately 5 pm/V from the most silicon-rich sample. Moreover, the optical losses were found to be sufficiently small (below 6 dB/cm) for applications. The tensorial results show that all samples retain in-plane isotropy independent of silicon content, highlighting the controllability of the fabrication process.Comment: 4 pages, 3 figures, 2 tables; Re-submitted to Optics Letter

Third order NLO properties of TTF-based self assembled molecular corners and polygons (poster presentation)

International audienc

Physical origin of third order NLO properties of TTF –based self assembled molecular corners and polygons

International audienc

Third order nonlinearities of TTF-based self-assembled molecular corners (oral presentation)

Date du colloque&nbsp;: 04/2010</p

Third order nonlinear optical response of self-assembled molecular corners

International audienc

Nonlinear Optical Response of Self-Assembled Molecular Corners

During the last years there is a growing effort in order to synthesize, functionalize and characterize modern molecular systems, which will have enhanced nonlinearities in order to be utilized in modern photonic applications. The nonlinearities are generally known to be significantly enhanced in systems which exhibit strong charge transfer within specially chosen moieties acting as electron donors or acceptors. Utilizing proper functionalization the charge transfer can be more enhanced by increasing the amount, as well as the mobility of the p-electrons of the systems. In this work we quantify the magnitude of the third order nonlinear susceptibility χ(3) of the TTF based molecular corners shown in Fig. 1, by the Degenerate Four Wave Mixing (DFWM) setup. Moreover by means of the Z-scan setup separate characterization of the nonlinear absorption of the systems is carried out. The advantage of these systems is that apart from their high nonlinearities can be combined in order to synthesize more complicated molecular systems like rotaxanes, catenanes etc

Photoinduced Gratings in Functionalized Azo-Carbazole Compounds in Picosecond Regime

We report results of diffraction grating inscription on thin films prepared from epoxy resin doped with azo-carbazole based dyes. Diffraction gratings were recorded at the wavelength 532 nm and monitored through intensity of first order of diffraction (632 nm). Atomic force microscope scans of the gratings show that a surface relief grating also appeared