Showing papers on "Semiconductor optical gain published in 1966"

Semiconductor lasers

Abstract: This paper is a review of semiconductor laser work. The principles of operation are discussed. The stress is on work since early 1964. The present state-of-the-art in GaAs junction lasers is described.

Semiconductor laser amplifier.

Abstract: IR GaAs laser amplifier with gains as high as 2000, output powers of 150 mw and saturation occurring with current increase at low light levels

Crystalline solid lasers

Abstract: A survey of crystalline solid lasers is presented. Crystalline host materials are described, pointing out their characteristics pertinent for laser systems. Rare earth and transition metal impurities operated as lasers are tabulated and the role of sensitization in increasing the overall efficiency of laser systems is described. Characteristics of operating CW lasers are given, and some applications and research directions are suggested.

9B4 - Semiconductor lasers with radiating mirrors

Abstract: High semiconductor gain coefficients (several hundreds of reverse centimeters) allow obtaining light generation by means of thin films imposed on the Fabri-Perot resonator mirror surface. In this case, semiconductor excitation can be produced by either light or an electron beam. With the help of such generators it becomes possible to significantly increase radiation energy and to improve its coherence. Coherent summing up of the radiation energy of several separate semiconductor or other types of lasers can be made through such a kind of system. At present, semiconductor lasers with radiating mirrors are developed by excitation using both an electron beam and a radiation of neodymium laser glass.

Electroluminescence and semiconductor lasers

Abstract: The various types of electroluminescence are discussed, with particular reference to the luminescence efficiency, and the materials in which electroluminescence has been observed are listed, Semiconductor lasers operating with electroluminescent, cathodoluminescent, or photoluminescent excitation, and some of the pertinent materials and operating parameters, are reviewed. All known semiconductor lasers are listed. Such devices are useful for a variety of applications, particularly if emission in the infrared region and operation at low temperatures is feasible. On the other hand, highly efficient visible electroluminescence or coherent emission has not been observed from any semiconductor at room temperature to date.

Chapter 14 Stimulated Emission in Semiconductor

Abstract: Publisher Summary This chapter discusses the aspects of stimulated emission in the case of semiconductor lasers Because most work has been done on gallium arsenide injection lasers, GaAs are used as the example and model Keyes has pointed out that an understanding of injection laser operation requires a chemical model, an electrical model, a thermal model, and an optical model These consider, in turn, the impurity profile and its production; the flow of electrons and holes; the heat flow; and the electronic transitions involved in the recombination, the quantum efficiency, and the electromagnetic modes of the laser The chapter discusses all these models but focuses on the optical model It discusses the relation between stimulated and spontaneous emission in semiconductors and describes the structure, both chemical and geometrical, of some of the many types of injection lasers that have been made and proposed and some of the characteristics of their emission The chapter also considers the mode structure, directionality, and coherence of the radiation emitted by injection lasers Quantum efficiency, both above and below threshold, is discussed in the chapter The effect of the optical properties of the semiconductor on the threshold current and other experimentally observed properties of GaAs lasers is considered in the chapter In the chapter, laser materials other than GaAs are discussed and some recent work on the excitation of stimulated emission by electron beams is referred The effects of temperature, pressure, strain, and magnetic field on semiconductor lasers are discussed in the chapter

7B11 - Theory of pulsating conditions for lasers

Abstract: A general equation is derived for the dynamical behavior of the laser The analytic form of the family of solutions to this equation is found for the practically most important case of deep modulation of the laser output The obtained results are used for studying a series of the following actual problems: external regulation of laser pulsation, establishment of continuous pulsating conditions for the maser and semiconductor lasers, and a study of periodic pulsations in a laser with a saturating filter

Quenching effects in coupled lasers

Abstract: The quenching of one pulsed ruby laser oscillation by another is investigated. Coupled rate equations, which yield both the steady-state and transient behavior of two coupled lasers, are the basis of a theoretical analysis of the interaction. An experimental investigation of the effect has been performed, and comparisons between theory and experiment are favorable.

9B9 - The theory of semiconductor lasers with consideration of saturation effects

Abstract: Semiconductor behavior in strong fields having a frequency close to the absorption band is considered. It is proved that only the slowing down and recombination times of four different relaxation times are of importance for weaker fields. In this case, equality of Fermi-level electron and hole quasi-levels to light quantum energy corresponds to a saturation condition. A semiconductor absorption coefficient regarding saturation is calculated.

9B4-Semiconductor Lasers with Ra

Abstract: Absfract-High semiconductor gain coefficients (several hundreds of reverse centimeters) allow obtaining light generation by means of thin films imposed on the Fabri-Perot resonator mirror surface. In this case, semiconductor excitation can be produced by either light or an electron beam. With the help of such generators it becomes possible to significantly increase radiation energy and to improve its coherence. Coherent summing up of the radiation energy of several separate semiconductor or other types of lasers can be made through such a kind of system. At present, semiconductor lasers with radiating mirrors are developed by excitation using both an electron beam and a radiation of neodymium laser glass. T THE PRESENT time there are a large number of publications on generation of coherent radiation in various semiconducting materials excited by a beam of accelerated electrons [1]-[14] and also by optical excitation [15]-[21]. In all these experiments generation was observed in the direction perpendicular to the axis of the exciting beam of electrons (or a beam of light). A pulsed oscillation power of approximately 100 kW was reported in [19] in which gallium arsenide mas excited by the St,oltes component of stimulated Ranzan scattering emitted by liquid nitrogen irradiated by the light from a ruby laser. This is several orders of magnitude greater than the maximum power of pin injection lasers. Attainment of such a power was possible as a result of the deep penet,ration of the pumping light in-to the semiconductor, as a result of which the generating volume of the semiconductor reached several cubic millimeters. Further increase in power of semiconductor lasers demands an increase in the volume of the active medium. However, in existing semiconductor lasers with a standard excitation scheme an increase in the volume of the active medium at the expense of an increase in the size of the cavit,y is 1imit.ed by losses due to defects of the crystal lattice and free-carrier absorption. Indeed, the total generat,ion power at the end of the laser with a FabryPerot cavity (see Fig. 1) may be written in the following manner :