H. Jerominek

CdS microcrystallites‐doped thin‐film glass waveguides

Thin films of Corning 7059, glass doped with CdS (2%–4% by weight) microcrystallites, with diameters presumably larger than 6 nm, were fabricated using rf sputtering technique. Sharp optical cutoff near 500 nm is visible on the absorption spectra of the films. Both Raman and absorption spectra presumably reveal the presence of size effects. At λ=632.8 nm the refractive index of the films varies from 1.55 to 1.69 depending on rf power. Propagation losses for TE0 guided mode are about 10 dB/cm.

Nonlinear optical properties of thin‐film waveguides deposited onto semiconductor‐doped glasses

We report the fabrication procedure and properties of optical nonlinear guided wave structures consisting of a thin film of Corning 7059 glass deposited on the surface of CdSxSe1−x doped glass. The limiting action in power‐dependent prism coupling in the structures produced is described. The nonlinear prism coupling is used to evaluate both the sign and the steady‐state value of the intensity‐dependent refractive index of the substrate. For the glass used the nonlinearity is negative and its value is in the range of 10−10 m2/W.

Nonlinear optical waveguides made of thin films of glass doped with semiconductor microcrystallites

The rf sputtering technique was used to deposit thin films of CdS microcrystallite-doped glass onto standard glass substrates. The presence of the microcrystallites in the films was verified by using Raman spectroscopy. A sharp cutoff below 500 nm was visible on the transmission spectra of the semiconductor microcrystallite-doped films. The evidence of size effects was visible on both Raman and transmission spectra of the films. Power-dependent prism coupling of light into the waveguides was investigated under cw-illumination conditions. The angular variation in decoupled power becomes more asymmetric with increasing input power until switching occurs on one side of the characteristic. The nonlinearity involved is presumably of thermal origin.

Optical branching effect in Ti:LiNbO3 waveguides: near-field pattern studies

The paper presents a detailed study of a single optical beam splitting into several beams (the branching effect) in photorefractive sensitive Ti:LiNbO3 optical slab waveguides. The near-field patterns of the multibeam structures are presented for different values of optical power coupled into TE guided modes of different orders. The process of partial recovery of the optically damaged waveguide (the partial shrinking of the multibeam bundle created) is also described.

Optical branching effect in photorefractive sensitive Ti:LiNbO 3 slab waveguides

This paper describes splitting of a single optical beam into several beams (the branching effect) in photorefractive sensitive Ti:LiNbO 3 slab waveguides. The branching effect is studied as a function of time and optical input power.

An integrated acousto-optic bistable device

Abstract Optical bistability experiments have been performed using an integrated acousto-optic modulator. Different experimental results are reported in this paper including optical hysteresis and differential gain behaviors. Possible modifications of the acousto-optic integrated bistable device are proposed.

Some properties of r.f. planar magnetron-sputtered corning 7059 glass films

Abstract Low loss Corning 7059 waveguides have been produced by r.f. magnetron sputtering in an oxygen-argon mixture. The influence of the sputtering process parameters on the deposition rate, refractive index, optical losses and stoichiometry of the films is described. It is shown that, contrary to the results obtained with standard r.f. sputtering, the increase in oxygen partial pressure in the sputtering atmosphere causes a significant increase in the refractive index. The dependence of the birefringence of the films on the deposition conditions is also presented.

Power-transfer effects in monomode optical nonlinear waveguiding structures

We describe power-transfer effects, over a certain threshold, among constituents of planar waveguiding structures consisting of an optical linear layer deposited onto a nonlinear substrate (CdS(x)Se(1-x)-doped glass). Proper selection of the thickness of the linear waveguiding film and the refractive index of the linear cladding allows one to obtain optical transistor action and to construct all-optical AND, OR, NOT, and XOR logic gates. The effects appear for the TE(0) guided mode.

Bistability and blocking oscillations in a total internal reflection integrated-optics device

Abstract A truly bistable device using an integrated total internal reflection modulator is reported. Bistable behaviour and blocking oscillations caused by the photorefractive effect are described.

Integrated optical oscillator consisting of an acoustooptic modulator and a surface acoustic wave delay line

Abstract We demonstrate the operation principle of an integrated acoustooptic bistable device using a surface acoustic wave delay line in the feedback loop. The transmitted light from the device exhibits a variety of bifurcation phenomena passing from a stationary state through successive periodic and chaotic states to a final developed chaotic state. The transitions between the harmonic waveforms accompanied by a hysteresis are also observable.