Nonlinear photoacoustics for measuring the nonlinear optical absorption coefficient

Nonlinear photoacoustics for measuring the nonlinear optical absorption coefficient.

We report a novel photoacoustic Z-scan (PAZ-scan) technique that combines the advantages offered by the conventional Z-scan method and the sensitivity of the photoacoustic detection. The sample is scanned through the focused laser beam and the generated photoacoustic signal is recorded using a 10 MHz focused ultrasound transducer. Since the signal strength is directly proportional to the optica...

Heterogeneous plasmonic trimers for enhanced nonlinear optical absorption

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...

The Third Order Nonlinear Optical behavior of Poly Ether Urethane

Poly (ether) urethane close/open cell (PEUCC/PEUOC) has been prepared by using in situ polymerization approach. The third-order optical nonlinearities of dissolved samples in DMF were characterized by Z-scan technique at the measurement wavelength of 532 nm. The synthesized samples were also examined by optical microscopy and UV-Vis absorption spectroscopy. The nonlinear refractive (NLR) indice...

Nonlinear optical absorption and dynamics in quantum wells

We present measurements of differential transmission and four-wave mixing in GaAs quantum well structures at 1.8 K near the inhomogeneously broadened lowest heavy-hole (hhl) exciton resonance using narrow band cw excitation. The data show an increase in absorption and an excitation lifetime of order l-10 ps outside the spectral hole produced by the pump. The long lifetime and the experimentally...

Two photon absorption, nonlinear refraction, and optical limiting in semiconductors