Picosecond pump-probe interferometric measurement of optical nonlinearities in channel waveguides.

An interferometric technique for measuring with picosecond resolution the time evolution of the real and imaginary components of optical nonlinearities in channel waveguides is described. Characteristics of the technique are illustrated with measurements of band-filling optical nonlinearities in CdS(x)Se(1-x)-doped glass channel waveguides.

Optical fibers with negative group-velocity dispersion in the visible.

Dispersion measurements have been performed in optical fibers having a photoinduced refractive-index grating in the core. The results show that negative group-velocity dispersion can be obtained in these fibers over a frequency region of 500 MHz for wavelengths shorter than 550 nm.

Exact dispersion relations for transverse magnetic polarized guided waves at a nonlinear interface.

We derive exact dispersion relations for transverse magnetic polarized guided waves at an interface between either a linear dielectric or a metal and a nonlinear dielectric. The nonlinearity is taken to be a Kerr-type nonlinearity. Numerical results are presented for the dielectric-metal case.

Prism coupling into ZnS waveguides: a classic example of a nonlinear coupler.

Prism coupling of an argon laser into a nonlinear ZnS waveguide was investigated for power slew rates much less than the nonlinearity relaxation time. The angular variation in coupling efficiency becomes progressively more asymmetric with increasing power until switching occurs on one side of the curve. For large detunings on the switching side, increasing absorption bistability was observed.

Beam-propagation method analysis of a nonlinear directional coupler.

The beam-propagation method is employed to analyze nonlinear directional-coupler operation for various combinations nonlinear materials and initially mismatched guides. A mixed focusing-defocusing configuration is found optimal results.

Comparison of solutions for TM-polarized nonlinear guided waves.

We show that physically realistic solutions for nonlinear TM waves guided by thin dielectric films are obtained in the uniaxial approximation for a dielectric constant proportional to the square of the normal-field component and not of the parallel-field component as assumed previously.

Observation of intensity-dependent guided waves.

We have observed an intensity-dependent hysteresis in the transmission of guided waves through a thin-film waveguide with a cladding characterized by an intensity-dependent refractive index. Good agreement with theory was obtained.

Nonlinear surface plasmons guided by thin metal films.

We have derived and solved numerically the dispersion relations for waves guided by a thin metal film bounded on one or both sides by media with intensity-dependent refractive indices. Depending on the conditions, the usual two modes can be cut off and can undergo radical changes in their field distributions, and new modes can exist above certain power threshholds.