Inversionless Amplification in a Three-Level System Driven by a Single Field

1995 ◽  
Vol 42 (2) ◽  
pp. 189-194
Author(s):  
Benjamin Fain ◽  
Vadim Khidekel
1984 ◽  
Vol 62 (8) ◽  
pp. 741-750 ◽  
Author(s):  
J. Grindlay ◽  
J. Mizia

Fourier transform techniques are used to obtain an approximate expression for the response of a quantum mechanical two-level system to a small monochromatic applied electric field. A comparison with the results of a numerical integration of the differential equations shows that the approximation is equally satisfactory close to and far from resonance. The method is easily extended to two or more applied fields.


Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.


Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy

In this chapter we study with the tools developed in Chapter 3 the basic models that are the foundations of light–matter interaction. We start with Rabi dynamics, then consider the optical Bloch equations that add phenomenologically the lifetime of the populations. As decay and pumping are often important, we cover the Lindblad form, a correct, simple and powerful way to describe various dissipation mechanisms. Then we go to a full quantum picture, quantizing also the optical field. We first investigate the simpler coupling of bosons and then culminate with the Jaynes–Cummings model and its solution to the quantum interaction of a two-level system with a cavity mode. Finally, we investigate a broader family of models where the material excitation operators differ from the ideal limits of a Bose and a Fermi field.


By the late second century, early Christian gospels had been divided into two groups by a canonical boundary that assigned normative status to four of them while consigning their competitors to the margins. The project of this volume is to find ways to reconnect these divided texts. The primary aim is not to address the question whether the canonical/non-canonical distinction reflects substantive and objectively verifiable differences between the two bodies of texts—although that issue may arise at various points. Starting from the assumption that, in spite of their differences, all early gospels express a common belief in the absolute significance of Jesus and his earthly career, the intention is to make their interconnectedness fruitful for interpretation. The approach taken is thematic and comparative: a selected theme or topic is traced across two or more gospels on either side of the canonical boundary, and the resulting convergences and divergences shed light not least on the canonical texts themselves as they are read from new and unfamiliar vantage points. The outcome is to demonstrate that early gospel literature can be regarded as a single field of study, in contrast to the overwhelming predominance of the canonical four characteristic of traditional gospels scholarship.


Author(s):  
S J Bhusal ◽  
R L Koch ◽  
A J Lorenz

Abstract Soybean aphid (Aphis glycines Matsumura (Hemiptera: Aphididae)) has been a major pest of soybean in North America since its detection in this continent in 2000 and subsequent spread. Although several aphid resistance genes have been identified, at least four soybean aphid biotypes have been discovered, with three of them being virulent on soybean cultivars with certain soybean aphid resistance genes. These biotypes are known to vary across years and locations, but information on their variation within single fields is limited. An investigation was conducted to study the variation of soybean aphid biotypes within single townships and fields in Minnesota. Screening of 28 soybean aphid isolates collected from seven soybean fields (six soybean fields in Cairo and Wellington Townships of Renville County, MN and one field in Wilmar Township of Kandiyohi County, MN) revealed the existence of multiple known biotypes of soybean aphid within single fields of soybean. We found up to three biotypes of soybean aphid in a single field. Two biotypes were found in five fields while only one field had only a single biotype. Three isolates presented reactions on a panel of resistant and susceptible indicator lines that were different from known biotypes. These results highlight the importance of characterizing soybean aphid biotypes in small geographical areas and utilizing generated knowledge to develop soybean cultivars pyramided with multiple resistance genes. The outcome will be decreased use of insecticides, thereby improving economic and environmental sustainability of soybean production.


2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Naftali Kirsh ◽  
Elisha Svetitsky ◽  
Alexander L. Burin ◽  
Moshe Schechter ◽  
Nadav Katz

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