Igory V. Mochalov

Laser and nonlinear properties of the potassium gadolinium tungstate laser crystal KGd(WO4)2:Nd3+-(KGW:Nd)

S. I. Vavilov State Optical InstituteState Research CenterScientific Research and TechnologicalInstitute of Optical Materials ScienceSt. Petersburg 193171, RussiaAbstract. The mechanical, thermophysical, spectroscopic, nonlinear,and laser properties are presented for one of the most efficient lasercrystals: neodymium-doped potassium gadolinium tungstate,KGd(WO

Optical information storage in glasses with nonbridging oxygen center

The possibility of optical information storage in sodium-tellurite glasses is demonstrated. The optical recording is based on the phenomena of the photoinduced second harmonic generation in glasses (PSHG). A microscopic model of this optical recording is suggested. The model is based on the analysis of optical transitions in nonbridging oxygen centers (NBO) (0.26 and 0.62 micrometers absorption bands and 0.65 micrometers photoluminescence band) in the frames of two-well adiabatic potential of NBO ground state. During simultaneous glass irradiation by YAG:Nd laser (1.06 micrometers ) and its second harmonic (0.53 micrometers ) the multiphoton 0.26 micrometers absorption in NBO band (under interference four- three- and two-photon processes) with subsequent photoluminescence leads to NBO moves from one stable position to another and to the recording macroscopic (Chi) (2)-grating.

Photoinduced chi recording in two- and multicomponent lead-silicate glasses for optical waveguides

The possibility of recording second-order nonlinear susceptibility in commercial and specially synthesized lead-silicate glasses was investigated. Effective photoinduced SHG in glasses with lead content from 10 to 40 mol% was found. Optical waveguides by ion-exchange were made in these glasses. Optimal content of Na2O in lead-silicate glasses for optical waveguides was found.

1.32 μm YAG:Nd Q-switch laser with YAG:V 3+ passive shutter

Q-switch performance of YAG:Nd at the wavelength of 1.32 μm under 2 W laser diode pumping has been studied using plane-plane and confocal resonator configurations. YAG:V3+ passive shutter has been applied. The pulse train with frequency 17 kHz and pulse duration of 8 ns have been obtained. An overage power of 430 mW and 160 mW were achieved in CW and Q-switch modes respectively, peak power in Q-switch mode being of 700 W.

Effect of resonance on rare-earth ions in second-order nonlinear susceptibility recording in glasses

The chi(2)-grating recording in barium-borosilicate glasses doped with Tb or La ions was investigated. Correlation between BaO content and PSHG efficiency was established. The comparison of the absorption spectra with the data of PSHG efficiency measurements allows us to assume the role of resonance transition in Tb3+ in the rising of PSHG effectiveness due to resonance increase of chi(3).

Second-harmonic generation in the bulk oxide glasses and planar optical waveguides

The second harmonic generation in the set of model lead-silicate glasses and also in lead-germanate glasses was investigated. The glass composition for effective second harmonic generation and optical waveguides has been optimized. Some features of optical waveguides formation in lead-silicate glasses were studied.

Photo-induced second-order nonlinear susceptibility in lead-silicate glasses and in planar waveguides on their basis

Possibility of recording second-order nonlinear susceptibility in commercial specially synthesized lead-silicate glasses was investigated. Photoinduced SHG in glasses with lead content from 10 to 40 mol% was found effective. Optical waveguides by ion-exchange were made in these glasses.

Influence of Nd3+ concentration on operation dynamics of picosecond laser with intracavity Raman conversion of radiation in KGd(WO4)2:Nd3+ crystals

The results of experimental investigation of cubic nonlinearity and Raman conversion efficiency dependencies on Nd-concentration in potassium gadolinium tungstate:Nd crystals are presented. These results are explained based on two-photon resonance and parametric processes theory.

Optical materials for information optics

We explore current technology and research in the field of optic materials properties for information optics, conducted at the S. I. Vavilov State Optical Institute, which is the largest such institute in the continent.

Resonant two-photon processes in impure Raman-active crystals

It was established that backward-scattered wave reflectivity from a signal wave intensity in neodimium-doped and undoped KGd(WO4)2-KGW crystals has different dependencies. The interference of electronic and Raman two-photon resonances in neodimium doped KGW crystals are described.