Volume 91, Issue 10, 15 May 2002
Index of content:
91(2002); http://dx.doi.org/10.1063/1.1473669View Description Hide Description
Detailed numerical analysis and computer simulation of a two-dimensional defective photonic crystalstructurefabricated with nonlinear optical materials are carried out. The localized states in the band gap and electric field distributions of such a structure were calculated by the finite-difference time-domain method, and demonstrated a greatly enhanced second harmonic generation with an efficiency of about 4 orders of magnitude higher than that in an ordinary nonlinear crystal.
91(2002); http://dx.doi.org/10.1063/1.1469200View Description Hide Description
We have investigated self-assembled islands grown on Si (001). We show that the average composition and both the and average strain components can be derived from Raman scatteringspectra. Both nm-sized and μm-sized islands are investigated. The experimental results are compared successfully with finite-element strain simulations. Raman scattering is shown to be a versatile and reliable tool for investigating capped and uncapped islands. It is shown that strain profiles in μm-sized islands can be obtained by means of micro-Raman.
91(2002); http://dx.doi.org/10.1063/1.1468276View Description Hide Description
The dielectric relaxation of thick (∼50 μm) films of was investigated from 10 Hz to 1.8 GHz at a temperature of 200 °C. Three separate measurement techniques were employed: time-domain discharge voltage measurement, frequency-domain impedance measurement, and frequency-domain reflection coefficientmeasurement, with overlapping frequency ranges. Four distinct regions of dispersion were observed: below 100 Hz, the permittivity and loss tangent rise, implying a relaxation process; between 25 kHz and 1 MHz a second region of dispersion is observed with a loss peak at 80 kHz; from 1 to 300 MHz the dielectric response obeys the power law of the Jonscher universal response with and above 500 MHz, another region of Debye-like loss is observed.