Signature of a three-dimensional photonic band gap observed on silicon inverse woodpile photonic crystals

We have studied the reflectivity of CMOS-compatible three-dimensional silicon inverse woodpile photonic crystals at near-infrared frequencies. Polarization-resolved reflectivity spectra were obtained from two orthogonal crystal surfaces corresponding to 1.88 pi sr solid angle. The spectra reveal broad peaks with high reflectivity up to 67 % that are independent of the spatial position on the crystals. The spectrally overlapping reflectivity peaks for all directions and polarizations form the signature of a broad photonic band gap with a relative bandwidth up to 16 %. This signature is supported with stopgaps in plane wave bandstructure calculations and with the frequency region of the expected band gap.Comment: 9 pages, 5 figure

Excitation of Coherent Phonons in Crystalline B: theory for driving atomic vibrations by femtosecond pulses

In this paper we present experimental and theoretical studies of reflectivity oscillations of an optical probe beam reflected from a single-crystal of bismuth excited by 35 fs laser pulses at deposited energy density above the melting temperature. Coherent and incoherent lattice dynamics as well as electrons dynamics were investigated starting from the reflectivity changes, measured with high accuracy ΔR/R < 10. The complex behaviour of the reflectivity could not be explained in the light of the existing theories. Therefore, we developed a new theory, starting from the very basic principles of lasermatter interaction, which shows good agreement with experimental results. We establish a direct dependence of the transient reflectivity on atomic motions driven by electron temperature gradient through electron-phonon coupling

Results of the Basin and Range Geoscientific Experiment (BARGE): A marine-style seismic reflection survey across the eastern boundary of the central Basin and Range Province

Approximately 120 km of marine-style deep seismic reflection data were shot during a survey on the waters of Lake Mead in southeastern Nevada. The survey extends from near the abrupt eastern edge of the Basin and Range Province (BRP) to a point ~80 km into the extended domain. Data quality throughout the survey ranged from fair to poor; the recorded data include significant towing noise and occasionally problematic diffractions and sideswipe from canyon walls. The upper 2–4 s of the data shows well-defined reflections from sedimentary fill, but below that point, reflectivity is weak. Lower crustal reflectivity is generally absent under the eastern part of the survey, with a slight increase in reflectivity to the west. The reflection Moho appears as a series of weakly defined, discontinuous reflections, most of which occur at 10–11 s. A particularly interesting feature of the data set is the relative lack of reflectivity from the lower crust, which is a region of strong reflectivity on other seismic reflection data sets from the BRP

Transverse magneto-optical Kerr effect in subwavelength dielectric gratings

We demonstrate theoretically a large transverse magneto-optical Kerr effect (TMOKE) in subwavelength gratings consisting of alternating magneto-insulating and nonmagnetic dielectric nanostripes. The reflectivity of the grating reaches $96\%$ at the frequencies corresponding to the maximum of the TMOKE response. The combination of a large TMOKE response and high reflectivity is important for applications in $3$D imaging, magneto-optical data storage, and magnonics