Power dependent nonlinear optical characteristics and two-photon absorption of NiO/PVA thin film

Two-photon absorption and nonlinear optical properties of octupolar molecules.

Two-photon absorption (TPA) cross sections of four representative series of octupolar molecules are theoretically investigated. The general structure--TPA-property relationship is described by using the effective four-state valence-bond three-charge-transfer model. As the charge-transfer character of the ground electronic state increases due to the strong donors or acceptors, (i) the transition...

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

The influence of self-absorption on the photoluminescence of thin film CdS demonstrated by two-photon absorption.

By means of two-photon excited photoluminescence, we demonstrate the influence of self-absorption on the emission properties of thin (1.5 microm) film CdS formed by laser ablation. The excitation of the sample is performed with 200 fs pulses at 804 nm (1.54 eV). The photoluminescence spectrum takes the form of a single peak centered at 510 nm (2.43 eV) at 300 K. The spectrum is shifted about 45...

Optical Absorption Enhancement in Freestanding GaAs Thin Film Nanopyramid Arrays

Although III–V compound semiconductor multi-junction cells show the highest effi ciency among all types of solar cells, their cost is quite high due to expensive substrates, long epitaxial growth and complex balance of system components. To reduce the cost, ultra-thin fi lms with advanced light management are desired. Here effective light trapping in freestanding thin fi lm nanopyramid arrays i...

Nonlinear optical susceptibility of multicomponent tellurite thin film glasses

Tellurite TeO2–TiO2–Nb2O5 thin film glasses have been produced by pulsed laser deposition. The dispersion of the real and imaginary parts of the linear refractive index has been measured in the range from 300 to 1700 nm. Films present high refractive index n=2.01 and reduced absorption k 10−4 at =1500 nm. The nonlinear third order optical susceptibility 3 has been determined at four different w...