Showing papers in "Applied Physics Letters in 1966"
942 citations
439 citations
435 citations
TL;DR: In this article, the authors investigated the temperature dependence of the carrier mean free path for optical phonon scattering and the mean energy loss per collision for any operating temperature once the appropriate parameters have been determined.
Abstract: Expressions for the temperature dependence of the carrier mean free path for optical phonon scattering and the mean energy loss per collision are presented which predict avalanche multiplication as a function of electric field for any operating temperature once the appropriate parameters have been determined at a single temperature. This has been verified for electrons in Si by the correlation of measurements at 300°K, 213°K, and 100°K. The temperature dependence of the breakdown voltages of a variety of abrupt and linear‐graded Si and Ge p‐n junctions has also been predicted. The fractional change in breakdown voltage with increasing temperature is predicted to decrease with increased doping concentration and, for the same breakdown voltage, to be less for linear‐graded junctions than for abrupt junctions.
419 citations
368 citations
TL;DR: In this article, the operation and characteristics of liquid lasers with a purely organic medium are described, and a giant-pulse ruby laser is used to pump solutions of organic dyes in various organic solvents in concentrations ranging from 10−3 to 10−6 moles/liter.
Abstract: The operation and characteristics of liquid lasers with a purely organic medium are described. A giant‐pulse ruby laser is used to pump solutions of organic dyes in various organic solvents in concentrations ranging from 10−3 to 10−6 moles/liter. The solutions are contained in plane‐parallel cuvettes acting as laser cavities. Wavelengths from 730 to 870 nm, megawatt peak powers and beam divergence angles of 5 mrad have been observed. The laser wavelength of each dye is tunable over a great part of its fluorescence band, e.g. by a change in concentration.
268 citations
TL;DR: In this paper, the spectral properties of Nd-doped YVO4, grown from the melt, have been determined, and the Nd ion appears to be in a cubic crystal field even though it substitutes for Y whose point symmetry is less than (42m).
Abstract: The spectral properties of Nd‐doped YVO4, grown from the melt, have been determined. In absorption the Stark split levels are reduced in comparison to other Nd‐doped materials. The Nd ion appears to be in a cubic crystal field even though it substitutes for Y whose point symmetry is less than (42m). The reduced Stark splitting, caused by an admixture of 4f and 5d wave functions, leads to efficient, low‐threshold laser action. Transfer of energy from the lattice to Nd ions is also observed.
252 citations
TL;DR: Birefringence of certain crystals sufficiently large to allow collinear backward wave interaction of three electromagnetic waves with signal frequency tunable over large portion of IR SPECTRUM as mentioned in this paper.
Abstract: Birefringence of certain crystals sufficiently large to allow collinear backward wave interaction of three electromagnetic waves with signal frequency tunable over large portion of IR SPECTRUM
238 citations
TL;DR: A theoretically calculated, automatically plotted, and photoreduced hologram has been successfully used to ''reconstruct'' the image of a nonexistent, three-dimensional, equilateral tetrahedron as discussed by the authors.
Abstract: A theoretically calculated, automatically plotted, and photoreduced hologram has been successfully used to ``reconstruct'' the image of a nonexistent, three‐dimensional, equilateral tetrahedron The theory, as presented therein, provides a synthetic hologram which consists only of completely opaque and transparent portions; allows reconstruction of the entire image with any fraction of the hologram as in conventional experimental types; can be made to reconstruct objects for either on‐ or off‐axis viewing; provides both a real and virtual image; and produces a positive image with both positive and negative prints
222 citations
208 citations
TL;DR: In this article, LiNbO3 and LiTaO3 were investigated from room temperature to temperatures above their ferroelectric phase transitions, showing that the phase change has the characteristics of a second-order Ferroelectric transition.
Abstract: Linear and nonlinear optical investigations of LiNbO3 and LiTaO3 from room temperature to temperatures above their ferroelectric phase transitions are described. The measurements include studies of second harmonic generation with an Nd laser (1.06 μ) and determinations of the refractive indices as well as the birefringence at 0.6328 μ. All the optical data exhibit distinct changes at the Curie temperatures, Tc = 1195°C ± 15°C for LiNbO3, and Tc = 610°C ± 10°C for LiTaO3. In each case the phase change has the characteristics of a second‐order ferroelectric transition. The uniaxial paraelectric phases are concluded to be centrosymmetric — probably space group R3c.
TL;DR: The light emitting diodes described in this article differ from standard type Diodes insofar as the amphoteric dopant Si is the dominant impurity on both sides of the junction.
Abstract: The light‐emitting diodes described in this Letter differ from standard type diodes insofar as the amphoteric dopant Si is the dominant impurity on both sides of the junction. The p‐n junction is completely solution regrown. The highly compensated p region gives rise to a wide active region up to 50 μ in width. The interesting feature of these diodes is their high external quantum efficiencies at 300°K. Values up to 6% have been measured on diodes, when an antireflecting coat has been applied.
TL;DR: In this paper, a novel way of imaging, in amplitude and phase, the cross section of a sound beam was reported, in which any arbitrary cross section can be brought into focus by optical manipulation without changing the relative position of light beam and sound beam.
Abstract: This Letter reports on a novel way of imaging, in amplitude and phase, the cross section of a sound beam. Because of the phase retention, any arbitrary cross section can be brought into focus by optical manipulation without changing the relative position of light beam and sound beam. The process is explained in terms of ray optics and various pertinent features are illustrated. Following a discussion about resolution, the experimental setup is described. Results show photographs of a 22‐MHz sound field behind various objects placed in the sound beam. In conclusion, the application to sound microscopy at higher sound frequencies is pointed out.
TL;DR: In this article, a Q-switched ruby laser was used to pump polymethine dyes with glycerol when pumped by a Q•switched Ruby laser.
Abstract: Stimulated emission is reported for two polymethine dyes dissolved in glycerol when pumped by a Q‐switched ruby laser. The materials are 1, 1'‐diethyl‐2,2'‐dicarbocyanine iodide, and 1, 1'‐diethyl‐4, 4'‐carbocyanine iodide. The emission wavelength is variable over the range 750 nm to 790 nm, depending on cell length. Oscillation has been observed on both the 0–0 and 0–1 vibrational transitions.
TL;DR: In this paper, a hologram has been made of an object illuminated by ultrasound, using the deformation of the water surface by radiation pressure, and an optical reconstruction of this sound hologram with laser light has been achieved.
Abstract: A hologram has been made of an object illuminated by ultrasound, using the deformation of the water surface by radiation pressure An optical reconstruction of this sound hologram with laser light has been achieved
TL;DR: Coupling between oppositely directed traveling waves in He-Ne ring laser in form of mutual backscattering of energy from each beam into direction of other is discussed in paper.
Abstract: Coupling between oppositely directed traveling waves in He-Ne ring laser in form of mutual backscattering of energy from each beam into direction of other