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It is shown that the dispersion of a prism beam expander used at very high angles of incidence has a large effect on the laser linewidth.

CW laser oscillation from singly ionized mercury at 6150 and 7945 A has been observed in a transverse-discharge slotted hollow-cathode laser. Population inversion is attributed to charge transfer and Penning-type ionization reactions.

A high-current electron-beam-semiconductor pulse amplifier was used to modulate an injection laser. Results show the capability of infrared output having faster rise time and shorter duration than can be obtained with commonly used types of pulse drivers.

We show theoretically and confirm experimentally that, by propagating a frequency-swept ultrashort pulse through an ensemble of two-level systems, it is possible to measure the time-dependent relative phase of the pulse with respect to that of the impact-excited oscillating resonant polarization. The phase is obtained from the intensity modulation of the pulse as measured by a cross-correlation technique.

The introduction of a glass prism in a ring dye laser is shown to provide simultaneous wavelength selection and pulse compression.

We present an experimental study of the pulse shape, delay, and spread of an optical pulse transmitted through a medium containing uniform latex microspheres using a mode-locked Nd:glass laser with a 20-psec pulse width. The delay of the arrival time of the peak intensity and the half-power pulse width for three different particle sizes are shown for an optical distance of up to 45.

Compression of intense Nd:YAG laser pulses by a fiber-grating compressor is investigated experimentally and theoretically. An increased stability of compressor operation in the Raman regime and a considerable further shortening of pulses with a compression factor of 130× is reported. A complete theoretical model of pulse compression is presented, including the combined action of self-phase modulation, stimulated Raman scattering, and group-velocity dispersion in the fiber. Detailed numerical calculations show the influence of laser input power on the shape, width, and peak intensity of compressed pulses for different fiber lengths and are directly compared with measurements.

Numerical simulation of a fiber-grating pulse compressor is performed assuming incident frequency chirped pulses. Characteristic fiber lengths are defined to explain qualitatively the behavior of the compression ratio curves. High compression ratios are not particularly sensitive to the input pulse chirp even for pulses of up to twice the bandwidth limit. The results are presented in normalized form with the help of optical soliton theory and can be used for a wide range of initial pulse widths.

Propagation of ultrashort pulses in single-mode fibers, which involves a third-order dispersion and a self steepening effect (optical shock), have been studied to obtain femtosecond pulses with a grating pair pulse compressor. These effects cause asymmetrically broadened and nonlinearly chirped optical pulses, which degrade the characteristics of the pulse compression. These effects can be partially compensated for and the compressed pulse width can be reduced by using a third-order term of the phase function of the grating pair.

It is shown that the dispersion of the prism material in a grating tuned dye laser containing an intracavity prism beam expander cannot be neglected in practical situations.