4,003 research outputs found
Optical diodes
Research on metal-barrier-metal structures is reviewed. Topics discussed include: demonstration of antenna coupling and rectification characteristics with high resistance evaporated structures at a wavelength of 10 microns; application of these devices to coherent conversion of laser radiation and infrared and optical circuit elements; and comparison of the point-contact type of diode structure and the newly developed photolithographic structures
Collaborative research in tunneling and field emission pumped surface wave local oscillators and amplifiers for infrared and submillimeter wavelengths under director's discretionary fund
Progress is reported in work towards the development of surface wave sources for the infrared and sub-millimeter portion of the spectrum to be based upon electron pumping by tunneling electrons in metal-barrier-metal or metal-barrier-semiconductor devices. Tunneling phenomena and the coupling of radiation to tunnel junctions were studied. The propagation characteristics of surface electro-magnetic modes in metal-insulator-p(++) semiconductor structures as a function of frequency were calculated. A model for the gain process based upon Tucker's formalism was developed and used to estimate what low frequency gain might be expected from such structures. The question of gain was addressed from a more fundamental viewpoint using the method of Lasher and Stern
Global dispersive solutions for the Gross-Pitaevskii equation in two and three dimensions
We study asymptotic behaviour at time infinity of solutions close to the
non-zero constant equilibrium for the Gross-Pitaevskii equation in two and
three spatial dimensions. We construct a class of global solutions with
prescribed dispersive asymptotic behavior, which is given in terms of the
linearized evolution
Coherent conversion of the sunlight spectrum
Efforts related to the utilization of tunneling junctions for the conversion of radiative power to electrical power are reported. The theoretical foundations for these particular devices is presented along with a discussion of many of the practical problems associated with the implementation of such devices
Electrodynamics of Media
Contains reports on two research projects.Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E
Self-steepening of light pulses
Self-steepening of light pulses due to propagation in medium with intensity-dependent index of refractio
Electrodynamics of Media
Contains research objectives and reports on one research project.Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 36-039-AMC-03200(E
The mean magnetic field of the sun: Observations at Stanford
A solar telescope was built at Stanford University to study the organization and evolution of large-scale solar magnetic fields and velocities. The observations are made using a Babcock-type magnetograph which is connected to a 22.9 m vertical Littrow spectrograph. Sun-as-a-star integrated light measurements of the mean solar magnetic field were made daily since May 1975. The typical mean field magnitude is about 0.15 gauss with typical measurement error less than 0.05 gauss. The mean field polarity pattern is essentially identical to the interplanetary magnetic field sector structure (seen near the earth with a 4 day lag). The differences in the observed structures can be understood in terms of a warped current sheet model
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