Influence of continuous wave laser light at 532 nm on transmittance and on photoluminescence of DNA-CTMA-RhB solutions

Recent results obtained in our experimental investigation on the influence of the illumination with continuous wave (c.w.) laser light at 532 nm on the transmittance at this wavelength and on the photoluminescence of the DNA-CTMA-RhB in butanol compound are reported. The temporal dependence of absorption changes induced by c. w. light at 532 nm in DNA-CTMA-RhB in butanol solution, and, for comparison, in RhB in butanol solution, is investigated experimentally and analyzed in order to assess the effect of DNA-CTMA on this light-induced process. The evolution in time of the peak's amplitude and wavelength of the photoluminescence spectra in solutions of DNA-CTMA-RhB in butanol, during their excitation with laser light at 532 nm wavelength has been also investigated and discussed

Ultrafast Third-Order Nonlinear Optical Response Excited by fs Laser Pulses at 1550 nm in GaN Crystals

The ultrafast third-order optical nonlinearity of c-plane GaN crystal, excited by ultrashort (fs) high-repetition-rate laser pulses at 1550 nm, wavelength important for optical communications, is investigated for the first time by optical third-harmonic generation in non-phase-matching conditions. As the thermo-optic effect that can arise in the sample by cumulative thermal effects induced by high-repetition-rate laser pulses cannot be responsible for the third-harmonic generation, the ultrafast nonlinear optical effect of solely electronic origin is the only one involved in this process. The third-order nonlinear optical susceptibility of GaN crystal responsible for the third-harmonic generation process, an important indicative parameter for the potential use of this material in ultrafast photonic functionalities, is determined

Use of quasi-local photorefractive response to generated superficial self-written waveguides in lithium niobate

International audienceWe report the formation of surface self-written waveguides by means of surface pyrolitons in lithium niobate. By a specific orientation of the crystal axis the quasi-local slow photorefractive response of lithium niobate was used to induce a self-confined beam exactly at the crystal-air interface. The mode profile of the photo-induced waveguide is strongly asymmetric due to the interface presence

Self-trapped beams in lithium niobate crystals doped with erbium

International audienc