Propagation of a light pulse in a resonantly amplifying (absorbing) medium
About: This article is published in Physics-Uspekhi.The article was published on 1970-05-01. It has received 137 citations till now. The article focuses on the topics: Pulse (physics).
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TL;DR: In this paper, the effect of the shape and the initial frequency chirp of input pulses on shape and spectrum of amplified pulses is discussed in detail and the case in which the input pulsewidth is comparable to the carrier lifetime so that the saturated gain has time to recover partially before the trailing edge of the pulse arrives.
Abstract: Amplification of ultrashort optical pulses in semiconductor laser amplifiers is shown to result in considerable spectral broadening and distortion as a result of the nonlinear phenomenon of self-phase modulation (SPM). The physical mechanism behind SPM is gain saturation, which leads to intensity-dependent changes in the refractive index in response to variations in the carrier density. The effect of the shape and the initial frequency chirp of input pulses on the shape and the spectrum of amplified pulses is discussed in detail. Particular attention is paid to the case in which the input pulsewidth is comparable to the carrier lifetime so that the saturated gain has time to recover partially before the trailing edge of the pulse arrives. The experimental results, performed by using picosecond input pulses from a 1.52- mu m mode-locked semiconductor laser, are in agreement with the theory. When the amplified pulse is passed through a fiber, it is initially compressed because of the frequency chirp imposed on it by the amplifier. This feature can be used to compensate for fiber dispersion in optical communication systems. >
1,175 citations
TL;DR: This paper deals with the dynamics of open systems moving irreversibly under the influence of their surroundings (B), and uses a complete microscopic description of the composite system S⊕B as a basis for the discussion of an open system S.
Abstract: This paper deals with the dynamics of open systems (S) moving irreversibly under the influence of their surroundings (B). As a basis for the discussion of an open system S we use a complete microscopic description of the composite system S⊕B. By eliminating the coordinates of B we infer the behavior of S. The motivation for this investigation is that nature frequently confronts us with coupled systems S and B only one of which, say S, is of experimental relevance. It is then a dictate of economy to look for a “closed” description of the dynamics of S alone. Let us mention just three out of the countless examples.
346 citations
TL;DR: In this article, a model of a passively mode-locked quasi-continuous laser is discussed and the evolution of pulses in various cavity configurations is traced and the combined action of amplifier and absorber saturation is shown to lead to rapid pulse compression even when the pulse duration is far shorter than the relaxation time.
Abstract: Various models of a passively mode-locked quasi-continuous laser are discussed and the evolution of pulses in various cavity configurations is traced. In certain circumstances, the combined action of amplifier and absorber saturation is shown to lead to rapid pulse compression even when the pulse duration is far shorter than the relaxation time of either nonlinear component. The results are in good agreement with recent streak- camera measurements involving the pulsed Rhodamine 6G dye laser and satisfactorily explain the efficient generation of picosecond pulses in CW dye-laser systems. The same pulse-compression mechanism can probably be used to generate ultrashort pulses in other quasi-continuous lasers.
266 citations
TL;DR: In this article, the gain medium and saturable absorber are placed in a single free-flowing dye stream located near the center of the resonator, and peak pulse powers of several kilowatts are obtained by acousto-optically dumping the mode-locked pulses from the optical cavity at repetition rates up to 105 pps.
Abstract: Subpicosecond pulses (0.5–1.0 psec) have been generated by passive mode locking of a composite medium dye laser. Both the gain medium and saturable absorber are placed in a single free‐flowing dye stream located near the center of the resonator. Peak pulse powers of several kilowatts have been obtained by acousto‐optically dumping the mode‐locked pulses from the optical cavity at repetition rates up to 105 pps.
235 citations
TL;DR: In this article, the authors present a review of high-power picosecond electronics, a branch of experimental engineering physics, whose dynamic development critically depends on national priority research projects.
Abstract: This paper reviews current research in high-power picosecond electronics, a branch of experimental engineering physics, whose dynamic development critically depends on national priority research projects. The aim of the review is basically to show progress in the study of picosecond processes involved in the accumulation, commutation, and transformation of high-density electric power. Examples are presented demonstrating what the latest built high-voltage picosecond facilities will potentially fundamentally contribute to developments in generating unique-property high-power electron beams and electromagnetic radiation pulses.
128 citations
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235 citations
01 Jan 1968
4 citations