International Business Machines Corporation

Bell Telephone Laboratories

Anvik Corporation

Gary C Bjorklund

Donald M Burland

Glenn T Sincerbox

William E Moerner

Scott Meixner Silence

Robert Dennis Miller

David M Bloom

Kanti Jain

Robert J Twieg

Marc David Levenson

William P Risk, Iii

Paul F Liao

Wilfried Lenth

Franklin M Schellenberg

Alan Edward Bell

Richard R Freeman

Victor B Jipson

Ralph H Storz

Heinrich E Hunziker

Martin Y Chen

Donald Maxwell Burland

Marcus C Donckers

Christopher P Ausschnitt

David C Alvarez

Urs P Wild

Christoph R Brauchle

Barry H Schechtman

Jean-Claude J Baumert

Cecilia A Walsh

Maskless patterning of high-resolution microelectronics features onto large curved substrates. A computer controls individual pixel elements in a spatial light modulator array (SLM) which provides the pattern. Maintaining optical track length constant is by software control of SLM vertical positioning, surface configuration and tilt. SLMs are on/off devices, either reflective or transmissive, such as digital micromirror devices (DMD) and liquid crystal light modulator arrays (LCLM). High-resolution spatial light modulator arrays currently have no capacity for changing or control of their average surface configurations. It is proposed to segment the SLM into smaller array chips, each mounted on a vertical positioner, such as a piezo-actuator, to provide the desired configuration to the surface defined by the spatial light modulator arrays. As an additional means to accommodate the variable surface configuration of the curved surface, a flexmirror (adaptive mirror) may be inserted between projection lens subsystem and the SLM array, defining the wavefront of pixel sub-beams striking the surface of the substrate and enabling the optical conjugates to be kept constant for a greater range of substrate curvatures.

Maskless conformable lithography

The present invention relates to an improved process for photorefractive index grating formation utilizing polymeric photorefractive materials. The process involves the steps of: (i) exposing a polymeric optical article to electromagnetic radiation having an intensity of at least 0.05 W/cm,for a short period of time to achieve an absorbed energy/unit volume of at least 1&times;10,J/cm,to activate the article, and (ii) exposing the polymeric optical article to an electric field and electromagnetic radiation to form an index grating.

Process for photorefractive index grating formation

The present invention relates to an improved process for producing photorefractive net gain two beam coupling utilizing polymeric materials.

Apparatus for photorefractive two beam coupling

A thermally written magnetic data storage medium retains desired domains of magnetization having field orientations representative of the data. A first magnetic layer retains one or more domains of desired magnetic field orientations. A second magnetic layer provides a biasing field for obtaining a predetermined magnetic field orientation in the first magnetic layer as a function of the temperature of the second magnetic layer. Disposed between the first and second layers is a thermal isolation layer which provides a thermal barrier for controlling the temperature of the second magnetic layer means. When the medium is heated for a short time, the fringe field from the first layer causes one direction of magnetic orientation to occur in a domain in the first layer. Upon cooling of the domain, the domain magnetization becomes stable with an orientation conforming to the orientation of the fringe field. The thermal isolation layer prevents significant heating of the second layer. Further heating of the domain to erase, heats the second layer substantially to cause it to project a field of predetermined direction opposite from the fringe field direction such that as cooling occurs, the orientation of the domain magnetization stabilizes and conforms to the projected field orientation.

Eraseable self biasing thermal magneto-optic medium

A process and apparatus are disclosed for producing a beam of coherent radiation at essentially 459 nm by mixing, in a nonlinear crystal consisting essentially of KTP, two laser beams, one at essentially 1064 nm and the other at essentially 808 nm. The 1064 nm radiation is derived from a Nd:YAG laser that consists of an input mirror, an output mirror and a Nd:YAG crystal, and contains also the KTP crystal. The Nd:YAG laser is pumped by an essentially 808 nm semiconductor diode laser beam, which passes through the input mirror and through the KTP crystal into the Nd:YAG laser crystal where it is absorbed. The 1064 nm radiation oscillating inside the Nd:YAG laser resonator is mixed either with the said 808 nm pump beam or with 808 nm radiation provided by a second semiconductor diode laser whose light is coupled with the 1064 nm beam using a beamsplitter. The essentially 459 nm beam passes through the output mirror to a utilization device.

Wide tolerance, modulated blue laser source

A time modulated source of frequency doubled laser radiation is described in which a non-linear crystal part of a stripline electrical circuit is mounted within a laser cavity so that the laser beam at a fundamental frequency impinges on and propagates through the non-linear crystal. A high bandwidth electrical data signal is coupled into the stripline electrical circuit to produce an electric field across the non-linear crystal so that an output beam is produced at a wavelength corresponding to the second harmonic of the fundamental frequency which represents a frequency doubled output beam modulated in accordance with the high bandwidth data signal, an alternate embodiment for producing the time modulated source of frequency doubled laser radiation has the non-linear crystal placed in a resonant microwave cavity. A high bandwidth electrical signal modulates the intensity of the microwave electric field across the non-linear crystal so that an output beam is produced at a wavelength corresponding to the second harmonic of the fundamental frequency which represents a frequency doubled output beam modulated in accordance with the high bandwidth data signal.

Modulated laser source for optical storage

Reversible phase change storage material is thermally isolated in a storage medium by means of grooves in the substrate and at least one layer of a thermally conductive dielectric material.

Thermal design for reversible phase change optical storage media

A frequency multiplexed optical spatial filter is based upon a thin film of a photochemical hole burning material. The filter stores a plurality of images in the photochemical hole burning medium. The images are formed at different optical frequencies and coexist in the same volume of the storage medium. Individual images are accessed by changing the frequency of the illuminating radiation.

Frequency multiplexed optical spatial filter based upon photochemical

A method and device for detecting dichroic and/or birefringent narrow spectral features in a sample is described. The method includes the steps of providing a beam of light having an optical frequency bandwidth which is narrow compared to the width of the narrow spectral feature and having a center frequency .omega..sub.c which lies near the narrow spectral feature, polarization phase modulating a beam of light with a single RF frequency to provide a pure FM spectrum having upper and lower sidebands in which either the carrier and sidebands have been polarized with respect to one another, exposing the sample containing the narrow spectral feature to the polarized modulated light so that the FM sidebands probe the narrow spectral feature, polarization analyzing and then photodetecting the light emerging from the sample to detect a RF beat at the specific RF frequency used for the polarization phase modulation, and electronically monitoring the amplitude of the RF beat signal to indicate the strength of the narrow spectral feature. The device includes a polarization phase modulator and a polarization analyzer positioned on opposite sides of the sample. In a preferred embodiment the polarization phase modulator produces a frequency modulated optical spectrum with the sidebands polarized precisely orthogonal to the carrier.

Frequency modulation-polarization spectroscopy method and device for

Information is stored by a process involving the steps of

Process for optical information storage

An inexpensive, high quality transmissive holographic optical element and method for making same are described. The holographic optical element consists of a potentially aberrating substrate which supports a layer of holographic recording material. The material contains a recorded fringe pattern that cancels the aberrations induced in an image wavefront as it passes through the aberrating substrate. This optical element is formed by a method having the following steps. A first wavefront from a source, for example a point focus, is passed through the aberrating substrate, becomes distorted, and then passes through the holographic recording material to a wavefront conjugator. The conjugator launches a conjugate of the distorted wavefront back to the holographic recording material. A second wavefront is then passed through the holographic recording material to form a fringe pattern or hologram as a result of the interference of the conjugate waveform and the second waveform. Subsequently, the developed holographic optical element is illuminated with a reconstruction wave which is the duplicate of the reference wave. Passage of this reconstruction wave through the holographic layer results in an emerging wavefront identical to the conjugated distorted wavefront which is then converted to the original wavefront as it passes through the aberrating substrate.

Transmissive holographic optical element on aberrating substrate

A gated self-developing, non-bleachable holographic material is disclosed which is useful in the infrared region. The holographic material comprises a polymeric matrix with an .alpha.-diketone compound uniformly dispersed therein.

Holographic recording media for infrared light

An apparatus utilizing four-wave degenerate mixing detects birefringence in irregularly shaped objects (6). Laser radiation (120) having a specified polarization is brought to a focus and then sent through the irregularly shaped object. The emerging radiation impinges upon a nonlinear material (8) to form a conjugate beam by means of four-wave degenerate mixing. The conjugate beam, which passes back through the object, is picked off and detected at a replica of the focus point. The detector (10, 11 and 12) includes a polarization detector (10) which is arranged so that a signal is detected only when the object has birefringence.

Detection of birefringence in irregularly shaped objects

A process and recording medium for four-level, two-photon holography are provided. These media are particularly useful for recording holograms using continuous wave lasers. The recording medium is formed by a transport resin containing a tetrazine compound.

Process and recording media for continuous wave four-level, two-photon

An optical pulse shaping device and methhod of shaping an optical pulse involves the use of a phase coherent multi-frequency light beam with an optical element consisting of a sample containing an absorption band with multiple holes. The holes are burned into the sample to selected depths at selected frequency locations, thereby permitting the relative phases and amplitudes of the input frequency components of the beam to be independently varied to arbitrary values. This system enables a generalized Fourier synthesis of optical pulses such as a laser with designed temporal profiles to be effected.

Growing community of inventors

Los Altos, CA, United States of America

Gary C Bjorklund