International Business Machines Corporation

The United States of America As Represented by the United States

Nabil M Amer

Robert J Von Gutfeld

Neil Adam Gershenfeld

Chai Wah Wu

Charles Philippe Tresser

Pradeep Kumar Dubey

Marco Martens

Gaurav Aggarwal

Sean William Smith

Bruce A Scott

Steve Harris Weingart

Ashutosh Kulshreshtha

David Peter DiVincenzo

Vernon Ralph Austel

Gerhard Meyer

Elia Zeldov

A method (and system) for guaranteeing authenticity of an object, includes providing a sample of material obtainable only by at least one of chemical and physical processes such that the sample is random and not reproducible, associating a number reproducibly to the sample by using a specific reader, and forming at least one coded version of the number, the at least one coded version being obtained by a key signature, and the version being recorded into an area of the object.

Method and apparatus for producing duplication- and imitation-resistant identifying marks on objects, and duplication- and duplication- and imitation-resistant objects

An atomic force microscope includes a tip mounted on a micromachined cantilever. As the tip scans a surface to be investigated, interatomic forces between the tip and the surface induce displacement of the tip. A laser beam is transmitted to and reflected from the cantilever for measuring the cantilever orientation. In a preferred embodiment the laser beam has an elliptical shape. The reflected laser beam is detected with a position-sensitive detector, preferably a bicell. The output of the bicell is provided to a computer for processing of the data for providing a topographical image of the surface with atomic resolution.

Atomic force microscopy

The multiple scattering of coherent radiation in an inhomogeneous medium is used to detect attempted intrusions into a protected area or into a tamper-proof package for such purposes as preventing the unauthorized detection and copying of electronic information used for authentication and coding in electronic commerce, communications, command, and control systems. A key advantage is that any intrusion into the sensed volume will produce a detected change in the measured intensity which will be equal to the full amplitude range if the intrusion is into a cylinder with radius comparable to the wavelength of the sensing radiation. The response of the medium can also be used to provide a unique identity key.

Tamper detection using bulk multiple scattering

The optical response of high-quality epitaxial copper-oxide perovskite films on substrates such as LaGaO.sub.3 and SrTiO.sub.3 exhibits a nonbolometric component to a photoresponse at certain temperatures below the onset of the superconducting transition and when carrying bias currents of a certain magnitude. A nonbolometric superconductive photoresponsive cell and method employ such films. The photoresponsive cell and method of the invention can be used to detect electromagnetic radiation incident on the film and to switch or modulate electrical signals passing through the film.

Nonbolometric superconductive photoresponsive

An apparatus and method for direct measurement for head/disc interface dynamics in a head/disc assembly is described incorporating two light beams positioned to reflect off two surfaces, two position sensitive detectors for receiving reflected light beams, and a processor for determining the displacement of the surfaces. The processor may further include circuitry for determining the change of displacement as a function of time of the two surfaces and for correlating displacement signals and change of displacement signals with themselves or with other predetermined stored signals to provide an indication of the operating status of the head/disc assembly. The invention overcomes the problem of experiencing unexpected head crashes and of predicting timely preventive maintenance of the head/disc assembly.

Direct access storage device with head-disc dynamics monitor

Successive minute regions (13) along a scan path on a coal sample (11) are individually analyzed, at a series of different depths if desired, to determine chemical composition including the locations, sizes and distributions of different maceral inclusions (12). A sequence of infrared light pulses (17) of progressively changing wavelengths is directed into each minute region (13) and a probe light beam (22) is directed along the sample surface (21) adjacent the region (13). Infrared wavelengths at which strong absorption occurs in the region (13) are identified by detecting the resulting deflections (.phi.) of the probe beam (22) caused by thermally induced index of refraction changes in the air or other medium (19) adjacent the region (13). The detected peak absorption wavelengths are correlated with known characteristic peak absorption wavelengths of specific coal constituents to identify the composition of each such minute region (13) of the sample (11). The method enables rapid, convenient and non-destructive analyses of coal specimens to facilitate mining, processing and utilization of coals.

Photothermal method for in situ microanalysis of the chemical

Predetermined amounts of heat are generated within a coal sample (11) by directing pump light pulses (14) of predetermined energy content into a small surface region (16) of the sample (11). A beam (18) of probe light is directed along the sample surface (19) and deflection of the probe beam (18) from thermally induced changes of index of refraction in the fluid medium adjacent the heated region (16) are detected. Deflection amplitude and the phase lag of the deflection, relative to the initiating pump light pulse (14), are indicative of the calorific value and the porosity of the sample (11). The method provides rapid, accurate and non-destructive analysis of the heat producing capabilities of coal samples (11). In the preferred form, sequences of pump light pulses (14) of increasing durations are directed into the sample (11) at each of a series of minute regions (16) situated along a raster scan path (21) enabling detailed analysis of variations of thermal properties at different areas of the sample (11) and at different depths.

Photothermal method of determining calorific properties of coal

A method and apparatus that significantly increases the sensitivity and flexibility of laser optoacoustic spectroscopy, with reduced size. With the method, it no longer is necessary to limit the use of laser optoacoustic spectroscopy to species whose absorption must match available laser radiation. Instead, 'doping' with a relatively small amount of an optically absorbing gas yields optoacoustic signatures of nonabsorbing materials (gases, liquids, solids, and aerosols), thus significantly increasing the sensitivity and flexibility of optoacoustic spectroscopy. Several applications of this method are demonstated and/or suggested.

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Berkeley, CA, United States of America

Nabil M Amer