T. K. Gustafson

SUBPICOSECOND PULSE GENERATION USING THE OPTICAL KERR EFFECT

A frequency modulation which is monotonic in time over a portion of an optical pulse can be utilized together with a dispersive delay line to obtain temporal compression of the pulse envelope. Short pulses (picosecond range) passed through an optical Kerr liquid receive a self‐phase‐modulation which exhibits a frequency sweep in the region of maximum intensity, the slope in time being proportional to the propagation distance. Frequency spreads of the order of 103 cm−1 are obtainable and hence significant compression ratios should be possible, giving rise to very short pulses in the range of 10−14 to 10−13 sec.

THERMALLY SELF‐INDUCED PHASE MODULATION OF LASER BEAMS

Self‐phase modulation of laser beams by media which possess a temperature‐dependent refractive index gives rise to far‐field aberrational rings. Steady‐state aberration profiles were measured and quantitative agreement with theory was obtained. A simple qualitative explanation of the ring structure is given. A self‐induced frequency modulation of 1.5‐W argon laser pulses was also observed and chirping detected.

Detection of optical and infrared radiation with DC-biased electron-tunneling metal-barrier-metal diodes

The voltage obtained from metal-barrier-metal (MBM) diodes by phase-sensitive detection when illuminated with optical and near-infrared radiation, modulated at 880 Hz, has been studied as a function of an applied dc bias. The detected voltage is a nonlinear function of the bias voltage for high junction impedances, and linear for low junction impedances. The nonlinearity in the junction has been shown to be consistent with electron tunneling theory.

Self‐phase modulation of picosecond pulses in optical fibers

Low‐intensity picosecond optical pulses from a mode‐locked cw dye laser have been observed to be self‐phase modulated upon propagation through a CS2‐filled glass fiber. This self‐phase modulation occurs in the absence of self‐focusing and has several interesting consequences with respect to pulse shaping and ultrashort‐pulse propagation.

Research on nonlinear optical materials: an assessment

The seven papers making up this assessment are based on the Workshop on Nonlinear Optical Materials held in April 1986.

Coupling characteristics of thin‐film metal‐oxide‐metal diodes at 10.6 μ

Coherent coupling of 10.6‐μm radiation into high‐resistance photolithographically fabricated metal‐oxide‐metal tunnel junctions has been demonstrated in direct detection experiments.

Diagrammatic evaluation of the density operator for nonlinear optical calculations

Time-ordered diagrammatic representations are shown to precisely define and to simplify calculations of radiative perturbations to the density matrix. Nonlinear optical susceptibilities, here exemplified by that of CARS, can be obtained by simple propagator rules. An interpretation of transient Raman scattering in terms of time-ordered contributions is also discussed.

Optical detection in thin‐film metal‐oxide‐metal diodes

Planar metal‐oxide‐metal diodes having cross‐sectional areas as small as 10−8 cm2 have detected optical radiation. Several possible detection mechanisms, including optical rectification, are discussed.

SELF‐TRAPPING IN MEDIA WITH SATURATION OF THE NONLINEAR INDEX

Numerical solutions of the nonlinear wave equation show that the steady‐state self‐trapping of optical beams in molecular fluids exhibits new characteristics when the intensity‐dependent index (orientational Kerr effect) begins to saturate. The power dependence of the beam diameter and the radial electric field distribution are examined. Beam diameters less than the wavelength of light are predicted for CS2 in the saturation regime.

Self - modulation of picosecond pulses in electro - optic crystals

Abstract The interaction of intense picosecond pulses with electro-optic crystals is investigated, with particular emphasis upon the resultant self-induced optical phase distortion. Observable spectral broadening of the optical field is predicted for propagation in GaAs.