Leland Stanford Junior University

California Institute of Technology

Jgm Associates, Inc.

Jgm Associated, Inc.

Joseph W Goodman

Yaakov Amitai

Jeffrey Glenn Manni

Abraham Aharoni

Herbert J Shaw

Lambertus Hesselink

John E Bowers

Demetri Psaltis

Jeffrey P Wilde

Behzad M Moslehi

Christophe Moser

Constance J Chang-Hasnain

Anujan Varma

Karsten Buse

Yonina Eldar

Moshe Tur

Kam-Yin Lau

Greg Steckman

Ingo Nee

Joerg Hukriede

Ellen Ochoa

An apparatus comprising a visible light source(s), multimode optical fiber(s), light coupler(s), an optional spatial light modulator(s), and an optional projection lens(es). The light source has a 1/e half-width emission bandwidth. The light coupler couples the light source to the multimode optical fiber(s) such that objective speckle contrast is reduced. The multimode optical fiber(s) may pass light from the coupler to an optional spatial light modulator. The spatial light modulator may modulate the light to form an image. The projection lens may transfer light onto an image plane or to illuminate objects. The objective speckle contrast at the end of the multimode fiber in combination with the projection lens diameter (if employed) and wavelength diversity may result in viewed images at the viewer's eye, or other detector, exhibiting speckle contrast that may be 1% or less.

Displays employing multimode optical fiber and low-speckle light sources

An apparatus comprising a laser and/or LED light source(s), multimode optical fiber(s), light coupler(s), an optional spatial light modulator(s), and an optional projection lens(es). The light source has a 1/e half-width emission bandwidth. The light coupler couples the light source to the multimode optical fiber(s) such that objective speckle contrast is reduced. The multimode optical fiber(s) may pass light from the coupler to an optional spatial light modulator. The spatial light modulator may modulate the light to form an image. The projection lens may transfer light onto an image plane or to illuminate objects. The objective speckle contrast at the end of the multimode fiber in combination with the projection lens diameter (if employed) and wavelength diversity may result in viewed images at the viewer's eye, or other detector, exhibiting speckle contrast that may be 1% or less.

Low-speckle light sources and displays employing multimode optical fiber

Systems, methods and devices are implemented for optical imaging. In one embodiment of the present disclosure, an optical imaging apparatus utilizes a laser-based coherent light source, and an optical device to pass grated light along an illumination direction from the laser-based coherent light source toward an object. Additionally, an illumination modulator is provided for changing angles at which the light, moving toward the object plane, reaches the object plane, and the light reaches the object plane at different angles. Further, the apparatus can include circuitry to process image-based data in response to and based on the light reaching the object plane at different angles for a user-viewable image of an object in proximity of the object plane.

Grating-enhanced optical imaging

The present invention is a method and apparatus for a rotating, tunable, holographic drop filter connected to a fiber optic source. The filter uses a quasi phase-conjugate optical system for a drop-channel fiber coupling and WDM channels which are introduced to the system. The light from these channels is collimated and passed through a volume phase holographic material so that only one WDM channel is diffracted and the rest pass through the holographic material unaffected. A quasi phase-conjugate diffracted beam is generated by the optical system to reflect the diffracted channel back towards the holographic material. The reflected light is Bragg matched to the holographic material so that it is re-diffracted along a path identical to the original incident light beam. A free-space circulator may be used to direct the diffracted beam to a fiber optic collimator, which is different from the fiber optic collimator of the incident light beam.

Tunable holographic drop filter with quasi phase-conjugate fiber coupling

An optical system is disclosed which focuses a polychromatic source to an extended focal pencil. The implementation makes use of two holographic optical elements (HOEs) fabricated and aligned to form a deliberate longitudinal color dispersion, but to alleviate lateral chromatic effects. Consequently, the HOE doublet focuses different wavelengths of the source to different locations along the optical axis. The strong intensity of the focused wavelengths dominate at each location, so that the overall beam has a near-diffraction-limited 1/e.sup.2 spot size and suffers only relatively weak background illumination. An alternative optical system using bulk lenses and several possible applications for the device are also described.

Chromatic focal pencil beam-generating apparatus

A network and method for routing optical signals through wavelength-coding of routing tags belonging to the optical signals. The routing tag preferably consists of one or more header pulses S.sub.i which are chosen from among header wavelengths .lambda..sub.hi. Preferably, the header wavelengths .lambda..sub.hi are different from wavelengths used by the data. The optical signal also has reset tag containing preferably one reset pulse R preferably having a unique reset wavelength .lambda..sub.r. The optical data is contained between the routing tag and the reset tag. The network has a splitter for dividing the optical signal into two or more split optical signals, which are copies of the original optical signal. A wavelength differentiating element is positioned in the path of one of the split optical signals to differentiate and preferably spatially resolve the header wavelengths of the header pulses. An opto-electronic control system, consisting of opto-electronic sensors and an electronic control circuit, generates electronic control signals based on the wavelength-coded information in the header tag. These electronic control signals are used to route one or more of the split optical signals through an optical switch. The network can be made up of one simple switch or a large number of complex switches.

Apparatus and method for routing optical signals through

The holographic element of the present invention includes a holographic grating pattern that is impressed in the media of the element utilizing beams of electromagnetic energy of wavelength .lambda..sub.o. The holographic grating pattern is capable of manipulating a beam of electromagnetic energy having a wavelength .lambda..sub.c at which the media is not necessarily suitable for recording. The method for manufacturing the holographic element utilizes an object beam and a reference beam having aspherical wavefronts of wavelength .lambda..sub.o to create the grating pattern in the media. In the preferred embodiment, the aspherical object beam and reference beam are created utilizing parent holographic devices recorded with spherical beams. An alternative embodiment of the present invention is a doublet holographic device which incorporates two holographic elements that are formed in accordance with the present invention to manipulate a beam of electromagnetic energy of wavelength .lambda..sub.c in a desired manner. The invention is particularly useful in obtaining high-quality volume phase holograms for use outside of the blue-green spectral range. A particular application is manipulating beams of electromagnetic energy from infrared laser diodes.

Single and multiple element holographic devices for high-efficiency beam

An optical system for selectively enhancing and/or suppressing the spectral intensity of components in an object beam, is disclosed. In one exemplary application, the optical system includes means for performing a forward transform operation on an input beam, a non-linear optical medium such as, for example, Bi.sub.12 SiO.sub.20 or Bi.sub.12 GeO.sub.20 and means for performing an inverse transform operation. In operation, the forward transform is performed on an input beam that contains a complex function characteristic of an object or subject, the resulting transform of the object beam is applied to the non-linear optical medium to form a hologram, then the hologram is read-out and the inverse transform operation is performed to provide an output optical beam that contains, for example, selectively enhanced intensity components and/or selectively suppressed intensity components. In one specific application, the object beam is obtained by transmitting a laser beam through a photomask such as, for example, the type used for fabricating semiconductor integrated circuits, the non-linear properties of the photorefractive crystal provide filtering or inversion of the intensity of the periodic aspects of the mask in the hologram and phase conjugate read-out and inverse transformation provide an image in which the intensity of the non-periodic defects is enhanced. In a second application, image inversion is employed to provide real-time inversion of intensity in the output image.

System for enhancement of optical features

An array (48, 49, 50, 51) of fiber optic couplers coupling an input (45) and an output (46) waveguide. The output waveguide (46) is routed among the couplers of the array such that either backward or forward coupling exists. With backward coupling, energy coupled into the output waveguide (46) in a coupler of the array is guided back to the preceding coupler for coupling back into the input waveguide (45). The backward coupling allows recirculations to occur between couplers to create poles and zeroes in the transfer function of the array which transfer function can be programmed or tailored somewhat to have specific characteristics. Further, the backward coupling allows the array to be used for matrix-vector multiplication.

Growing community of inventors

Los Altos, CA, United States of America

Joseph W Goodman