The optical waveguide lens is an important and basic component in many integrated optical devices, performing such functions as focussing and collimating, Fourier transformation and optical signal processing. For many...
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The optical waveguide lens is an important and basic component in many integrated optical devices, performing such functions as focussing and collimating, Fourier transformation and optical signal processing. For many applications of the optical waveguide lens, diffraction-limited performance is required. Such a stringent focussing criterion necessitates careful control of the design parameters and fabrication procedure, as well as the in situ variables which may affect the lens performance. The design and performance of geodesic lenses and grating lenses have been treated in the past. However, for the mode-index lens, among which the Luneburg lens' shown in Fig. 1, is perhaps the most common, no complete examination of the fabrication tolerances has been made.
作者：
J. J. SimpsonDepartment of Physics
Guelph-Waterloo Program for Graduate Work in Physics University of Guelph Guelph Ontario Canada N1G 2W1
The half-life of tritium implanted into a Si(Li) x-ray detector has been determined to be 12.32±0.03 yr by following the decay for about 5.5 years. Using a recently determined β-decay end-point energy for the sa...
The half-life of tritium implanted into a Si(Li) x-ray detector has been determined to be 12.32±0.03 yr by following the decay for about 5.5 years. Using a recently determined β-decay end-point energy for the same system, the product (GA/GV)〈στ〉 for tritium has been determined to be 2.094±0.004.
Emission in the visible has been observed from dense, cold helium gas in contact with solid hydrogen when irradiated by a 15-MeV proton beam. All four stable isotopic combinations have been studied, and the spectrum o...
Emission in the visible has been observed from dense, cold helium gas in contact with solid hydrogen when irradiated by a 15-MeV proton beam. All four stable isotopic combinations have been studied, and the spectrum of one of them, HeD4, appears highly perturbed. Spectral identification of rotational features and a plausible explanation of the perturbation have been provided by rovibrational energy-level calculations.
A scaling hypothesis is set up for the correlation function G(R,T;L) of a finite-sized system, with O(n) symmetry (n≥2), confined to geometry Ld−d’×∞d’ (2<d<4, d’≤2) and subjected to periodic boundary...
A scaling hypothesis is set up for the correlation function G(R,T;L) of a finite-sized system, with O(n) symmetry (n≥2), confined to geometry Ld−d’×∞d’ (2
The scaling hypothesis on the 'singular' part of the free-energy density of a finite system is examined in the context of a relativistic Bose gas confined to an Einstein universe of radius R. Finite-size effec...
The scaling hypothesis on the 'singular' part of the free-energy density of a finite system is examined in the context of a relativistic Bose gas confined to an Einstein universe of radius R. Finite-size effects in the various thermodynamic properties of the system, such as the free energy, the specific heat, the isothermal compressibility and the condensate density, are predicted in the regions of both first-order (T
Anodic oxidation of III–V semiconductors provides excellent control of oxide thickness and high chemical etch selectivity. Rutherford backscattering spectrometry (RBS) and Auger electron spectroscopy (AES) were used ...
Anodic oxidation of III–V semiconductors provides excellent control of oxide thickness and high chemical etch selectivity. Rutherford backscattering spectrometry (RBS) and Auger electron spectroscopy (AES) were used to characterize the oxides grown on GaInAs. Epilayer compositions with the Ga mole fraction ranging from 0.43 to 0.56 were used. The oxides were found to have uniform composition throughout their thickness, except when anodic growth was done using an electrolyte with tartaric acid buffered by NH4OH to a pH of 7.0. Under high pH (∼7) conditions, anodization was associated with nonuniform In or O concentrations. Compositional analysis of the AES sputter depth data was accomplished by using appropriate sensitivity factors, obtained from standards and by RBS measurement of the In/(Ga+As) ratios. RBS ratios were invaluable since there was strong correlation between the In concentration and its sensitivity factor, ranging (exponentially) from ∼0.75 at 6% In to ∼0.6 at 8% In. All the oxides had near stoichiometric O content but were In deficient, irrespective of the epilayer composition or the anodization conditions.
Laser measurements at 23.13 cm? 1 of collision‐induced absorption are described using absorption cells over 1500 cm in length and a liquid‐helium‐cooled bolometer. Also reported are a number of improvements over a ...
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Laser measurements at 23.13 cm?1 of collision‐induced absorption are described using absorption cells over 1500 cm in length and a liquid‐helium‐cooled bolometer. Also reported are a number of improvements over a previously described system operating at different laser frequencies. The improvements are related to the method of data collection and operation of the system which result in an increased accuracy of determination of the absorption coefficients of nonpolar condensed gases. Typical results are given for the cells used in the temperature range from 126 to 410 K at pressures up to 1500 psi.
Scaling hypothesis on the ‘‘singular’’ part of the free-energy density of a finite system is examined in the context of a Bose gas confined to an enclosure of size Ld−d’×∞d’, with 2<d<4 and d’≤2, u...
Scaling hypothesis on the ‘‘singular’’ part of the free-energy density of a finite system is examined in the context of a Bose gas confined to an enclosure of size Ld−d’×∞d’, with 2
A simple force constant model is used to calculate the normal mode frequencies and eigenvectors of the carbon disulphide crystal. By adjustment of three intramolecular and four intermolecular parameters, good agreemen...
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A simple force constant model is used to calculate the normal mode frequencies and eigenvectors of the carbon disulphide crystal. By adjustment of three intramolecular and four intermolecular parameters, good agreement with spectroscopic data is obtained for the lattice mode frequencies and for the crystal field splittings of the molecular modes. Es wird ein einfaches Kraftkonstantenmodell benutzt, um die Normalmodenfrequenzen und Eigenvektoren des Kohlenstoffdisulfidkristalls zu berechnen. Durch Anpassung von drei intramolekularen und vier intermolekularen Parametern wird gute Übereinstimmung mit spektroskopischen Werten für die Gittermodenfrequenzen und für die Kristallfeldaufspaltungen der Molekülmoden erhalten.
The problem of localized single-particle excitations and the density of states (DOS) for an inhomogeneous system consisting of a spherical superconductor (with radius a and order parameter Δ1) embedded in another sup...
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The problem of localized single-particle excitations and the density of states (DOS) for an inhomogeneous system consisting of a spherical superconductor (with radius a and order parameter Δ1) embedded in another superconductor (order parameter Δ2) of infinite size is considered. With the assumption of constant values of Δ1and Δ2, the Bogoliubov equations are solved for general values of l (the orbital angular momentum quantum number). For a fixed value of Δ1/Δ2and different values of Δ2/EF, the dependence of the excitation energy ε(l=0)/Δ2on the particle sizekFa is shown(kFis the Fermi wave vector andEFis the Fermi energy). ForkFa=300, 450, and 800 and a fixed value of Δ2/EF, the variations in the DOS by changing Δ1/Δ2are
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