Schlumberger Technology Corporation

University of Rochester

Wea Manufacturing, Inc.

Time Warner Inc.

Emil Wolf

Yajun Li

Anthony J Devaney

Michael L Oristaglio

An improved light-readable information recording medium is provided that comprises an optical data storage structure having lands and pits, in which the depth of the pits is about: wherein &#x3bb; is the wavelength of light used to read the information recording medium, m is the order of interference selected from a group consisting of odd integers, Mis the transverse magnification, and n is the refractive index encountered by the reading light inside the pits. The invention also provides an improved optical reading system with the parameters satisfying the relationship: wherein &#x3bb; is the wavelength of light used to read the information recording medium, m is the order of interference selected from a group consisting of odd integers, Mis the transverse magnification, n is the refractive index encountered by the reading light inside the pits, and d is the depth of the pits.

Optical information recording medium based on interference of converging spherical waves

Interference of converging spherical waves with application to the design of light-readable information-recording media and systems for reading such media

Optical filters and filter systems operate in accordance with correlation-induced spectral changes and are applied for spectral line resolution in spectrometry, for optical data processing and for cryptography, as by having prescribed filtering properties in different directions of observation.

Coherence filters and systems utilizing same

Disclosed is separation of the compressional and shear components of the wavefield measured in 3-component vertical seismic profiling. The separation involves working in the zx plane defined by the borehole axis (z) and the surface seismic source, and in successive and overlapping windows each defined by (i) a depth interval centered at the depth level currently being processed and including several depth levels above and below and (ii) a time interval sufficiently long to include the receipt of the relevant seismic energy by the geophones. The total wavefield measurements in a window are rotated to give the energy along the borehole axis (z) and that perpendicular to it in the zx plane of interest, the result is forward Fourier transformed in two dimensions, then filtered in wavenumber-frequency space by means of a matrix filter which depends on previously estimated compressional and shear speeds of the region that produced the VSP measurements being filtered, and the result is inverse Fourier transformed to derive the compressional component. Subtracting the compressional component from the total measured wavefield gives the shear component. The corresponding operations performed entirely in the spatial domain give corresponding results.

Compressional/shear wave separation in vertical seismic profiling

Growing community of inventors

Rochester, NY, United States of America

Emil Wolf