Patents by Inventor Demetri Psaltis

Demetri Psaltis has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20150265157
    Abstract: This invention is a method and apparatus to pick up a photoacoustic signal purely via optical means and via an endoscope. The photoacoustic endoscope invention relies only on optical excitation and detection methods. A light focus spot generates a photoacoustic signal at the distal end of a multimode fiber endoscope. A membrane is positioned at the distal end whose vibration is excited by the acoustic signal. A light beam brought at the distal end of the multimode endoscope via the single mode core of a dual clad multimode fiber is reflected by the said vibrating membrane. The light reflected is capture by the multimode core of the dual clad fiber and propagates to the proximal end. The speckle pattern thus generated at the proximal end depends on the membrane acoustic vibration.
    Type: Application
    Filed: March 23, 2015
    Publication date: September 24, 2015
    Applicant: ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
    Inventors: Demetri PSALTIS, Christophe MOSER
  • Publication number: 20150015879
    Abstract: A multimode waveguide illuminator and imager relies on a wave front shaping system that acts to compensate for modal scrambling and light dispersion by the multimode waveguide. A first step consists of calibrating the multimode waveguide and a second step consists in projecting a specific pattern on the waveguide proximal end in order to produce the desire light pattern at its distal end. The illumination pattern can be scanned or changed dynamically only by changing the phase pattern projected at the proximal end of the waveguide. The third and last step consists in collecting the optical information, generated by the sample, through the same waveguide in order to form an image. Known free space microscopy technique can be adapted to endoscopy with multimode waveguide, such as, but not limited to, fluorescence imaging or Raman spectroscopy or imaging, 3D linear scattering imaging or two-photon imaging. Super-resolution, i.e.
    Type: Application
    Filed: March 28, 2013
    Publication date: January 15, 2015
    Inventors: Ioannis Papadopoulos, Salma Farahi, Christophe Moser, Demetri Psaltis
  • Publication number: 20140303504
    Abstract: Systems and methods for imaging ear tissue include: directing illumination radiation to pass through an intact biological structure and be incident on ear tissue that does not include an exogenous fluorophore, at a plurality of locations, the illumination radiation including a plurality of light pulses each having a temporal duration of 500 femtoseconds or less; for each one of the plurality of locations, using a detector to detect radiation emitted from the location that passes through the intact biological structure; and forming an image of the tissue based on the detected radiation at each of the plurality of locations, where the emitted radiation corresponds to endogenous two-photon fluorescence of the tissue.
    Type: Application
    Filed: October 29, 2012
    Publication date: October 9, 2014
    Inventors: Konstantina Stankovic, Demetri Psaltis, Xin Yang, Ye Pu, Chia-Lung Hsieh
  • Patent number: 8675201
    Abstract: Apparatus and methods of four wave mixing (FWM) holography are described, including illuminating a sample with a first beam, a second beam, and a third beam, and combining the generated FWM signal with a reference beam at a imaging device to obtain holographic image data. In some examples, the first and second beams may be provided by a single pump-probe beam. The third beam may be a Stokes beam or an anti-Stokes beam. A representative example is coherent anti-Stokes Raman holography (CARS holography), which includes illuminating a sample with a pump/probe beam and a Stokes beam to obtain a CARS signal from the sample; and combining the CARS signal with a reference beam to obtain a CARS hologram.
    Type: Grant
    Filed: June 4, 2010
    Date of Patent: March 18, 2014
    Assignee: The Penn State Research Foundation
    Inventors: Zhiwen Liu, Kebin Shi, Demetri Psaltis, Qian Xu
  • Patent number: 8411282
    Abstract: A differential interference contrast (DIC) determination device and method utilizes an illumination source, a layer having a pair of two apertures that receive illumination from the illumination source, and a photodetector to receive Young's interference from the illumination passing through the pair of two apertures. In addition, a surface wave assisted optofluidic microscope and method utilize an illumination source, a fluid channel having a layer with at least one aperture as a surface, and a photodetector that receives a signal based on the illumination passing through the aperture. The layer is corrugated (e.g., via fabrication) and parameters of the corrugation optimize the signal received on the photodetector.
    Type: Grant
    Filed: June 9, 2011
    Date of Patent: April 2, 2013
    Assignee: California Institute of Technology
    Inventors: Xiquan Cui, Changhuei Yang, Axel Scherer, Demetri Psaltis, Xin Heng
  • Publication number: 20120277593
    Abstract: An imaging based interferometric pressure sensor apparatus compromise a fluid pressure sensor unit (1) and an optical monitor (2). The disposable pressure sensor part comprises a rigid transparent cover plate 3 and a flexible diaphragm (4), in between forming an air-gap cavity (8). By illuminating the air-gap cavity (8) with a light source (6), the air-gap cavity generates an interference pattern which is captured by the optical imaging device (7). The pressure of the fluid (5) to be sensing is applied to flexible diaphragm, causing the deformation of the diaphragm and the variation of the air-gap thickness. Hence the interference pattern varies with pressure of fluid. The optical monitor (2) includes light source 6 and optical image device (7) which records the interference pattern from the fluid pressure sensor unit (1). The pressure of the fluid is measured by processing the captured image.
    Type: Application
    Filed: October 28, 2010
    Publication date: November 1, 2012
    Inventors: Wuzhou Song, Demetri Psaltis
  • Publication number: 20120141981
    Abstract: Second harmonic nanoprobes for imaging biological samples and a method of using such probes to monitor the dynamics of biological process using a field resonance enhanced second harmonic (FRESH) technique are provided. The second harmonic generating (SHG) nanoprobes are comprised of various kinds of nanocrystals that do not possess an inversion symmetry and therefore are capable of generating second harmonic signals that can then be detected by conventional two-photon microscopy for in vivo imaging of biological processes and structures such as cell signaling, neuroimaging, protein conformation probing, DNA conformation probing, gene transcription, virus infection and replication in cells, protein dynamics, tumor imaging and cancer therapy evaluation and diagnosis as well as quantification in optical imaging.
    Type: Application
    Filed: November 21, 2007
    Publication date: June 7, 2012
    Inventors: Periklis Pantazis, Ye Pu, Demetri Psaltis, John H. Hong, Scott E. Fraser
  • Patent number: 8189204
    Abstract: Embodiments of the present invention relate to a surface wave enabled darkfield aperture structure comprising an aperture layer, a aperture in the aperture layer and a plurality of grooves around the aperture. The aperture layer has a first and second surface. The plurality of grooves is in the first surface. A surface wave propagates along at least the first surface. The plurality of grooves is configured to generate a darkfield at the aperture by modifying the surface wave to cancel out direct transmission of a uniform incident light field received by the aperture.
    Type: Grant
    Filed: June 2, 2010
    Date of Patent: May 29, 2012
    Assignee: California Institute of Technology
    Inventors: Xiquan Cui, Xin Heng, Changhuei Yang, Axel Scherer, Demetri Psaltis, Guoan Zheng
  • Publication number: 20120026509
    Abstract: A differential interference contrast (DIC) determination device and method utilizes an illumination source, a layer having a pair of two apertures that receive illumination from the illumination source, and a photodetector to receive Young's interference from the illumination passing through the pair of two apertures. In addition, a surface wave assisted optofluidic microscope and method utilize an illumination source, a fluid channel having a layer with at least one aperture as a surface, and a photodetector that receives a signal based on the illumination passing through the aperture. The layer is corrugated (e.g., via fabrication) and parameters of the corrugation optimize the signal received on the photodetector.
    Type: Application
    Filed: June 9, 2011
    Publication date: February 2, 2012
    Applicant: CALIFORNIA INSTITUTE OF TECHNOLOGY
    Inventors: Xiquan Cui, Xin Heng, Changhuei Yang, Axel Scherer, Demetri Psaltis
  • Patent number: 7982883
    Abstract: A differential interference contrast (DIC) determination device and method utilizes an illumination source, a layer having a pair of two apertures that receive illumination from the illumination source, and a photodetector to receive Young's interference from the illumination passing through the pair of two apertures. In addition, a surface wave assisted optofluidic microscope and method utilize an illumination source, a fluid channel having a layer with at least one aperture as a surface, and a photodetector that receives a signal based on the illumination passing through the aperture. The layer is corrugated (e.g., via fabrication) and parameters of the corrugation optimize the signal received on the photodetector.
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: July 19, 2011
    Assignee: California Institute of Technology
    Inventors: Xiquan Cui, Xin Heng, Changhuei Yang, Axel Scherer, Demetri Psaltis
  • Publication number: 20110075254
    Abstract: Embodiments of the present invention relate to a surface wave enabled darkfield aperture structure comprising an aperture layer, a aperture in the aperture layer and a plurality of grooves around the aperture. The aperture layer has a first and second surface. The plurality of grooves is in the first surface. A surface wave propagates along at least the first surface. The plurality of grooves is configured to generate a darkfield at the aperture by modifying the surface wave to cancel out direct transmission of a uniform incident light field received by the aperture.
    Type: Application
    Filed: June 2, 2010
    Publication date: March 31, 2011
    Inventors: Xiquan Cui, Xin Heng, Changhuei Yang, Axel Scherer, Demetri Psaltis, Guoan Zheng
  • Publication number: 20110063623
    Abstract: A differential interference contrast (DIC) determination device and method utilizes an illumination source, a layer having a pair of two apertures that receive illumination from the illumination source, and a photodetector to receive Young's interference from the illumination passing through the pair of two apertures. In addition, a surface wave assisted optofluidic microscope and method utilize an illumination source, a fluid channel having a layer with at least one aperture as a surface, and a photodetector that receives a signal based on the illumination passing through the aperture. The layer is corrugated (e.g., via fabrication) and parameters of the corrugation optimize the signal received on the photodetector.
    Type: Application
    Filed: June 25, 2010
    Publication date: March 17, 2011
    Applicant: CALIFORNIA INSTITUTE OF TECHNOLOGY
    Inventors: Xiquan Cui, Xin Heng, Changhuei Yang, Axel Scherer, Demetri Psaltis
  • Publication number: 20100309465
    Abstract: Apparatus and methods of four wave mixing (FWM) holography are described, including illuminating a sample with a first beam, a second beam, and a third beam, and combining the generated FWM signal with a reference beam at a imaging device to obtain holographic image data. In some examples, the first and second beams may be provided by a single pump-probe beam. The third beam may be a Stokes beam or an anti-Stokes beam. A representative example is coherent anti-Stokes Raman holography (CARS holography), which includes illuminating a sample with a pump/probe beam and a Stokes beam to obtain a CARS signal from the sample; and combining the CARS signal with a reference beam to obtain a CARS hologram.
    Type: Application
    Filed: June 4, 2010
    Publication date: December 9, 2010
    Applicant: The Penn State Research Foundation
    Inventors: Zhiwen Liu, Kebin Shi, Demetri Psaltis, Qian Xu
  • Publication number: 20100296094
    Abstract: An optofluidic microscope device is disclosed. The device includes a fluid channel having a surface and an object such as a bacterium or virus may flow through the fluid channel. Light transmissive regions of different sizes may be used to image the object.
    Type: Application
    Filed: May 24, 2010
    Publication date: November 25, 2010
    Inventors: Changhuei Yang, Demetri Psaltis
  • Publication number: 20100290049
    Abstract: An optofluidic microscope device is disclosed. The device includes a fluid channel having a surface and an object such as a bacterium or virus may flow through the fluid channel. Light imaging elements in the bottom of the fluid channel may be used to image the object.
    Type: Application
    Filed: June 9, 2010
    Publication date: November 18, 2010
    Applicant: CALIFORNIA INSTITUTE OF TECHNOLOGY
    Inventors: Changhuei Yang, Demetri Psaltis
  • Patent number: 7826125
    Abstract: A light conductive controlled shape droplet display device of the invention includes a light source. A light conductive substrate receives and conducts light from the light source. A cover disposed relative to the substrate, conducts light received from the substrate out and away from the display device. Pixels in the display are defined by fluid droplets in optical communication with the substrate and the cover. Hydrophobic layers associated with the substrate and the cover control the shape of the fluid droplet in conjunction with properties of the fluid droplet. Persistent displays are possible, as are displays that require periodic refresh to maintain the display. Electrodes modulate the amount of light conducted by the fluid droplets from the substrate into the cover. In preferred embodiments, each pixel includes sub-pixels formed by different primary colored fluid droplets.
    Type: Grant
    Filed: June 12, 2006
    Date of Patent: November 2, 2010
    Assignee: California Institute of Technology
    Inventors: Demetri Psaltis, Allen Pu
  • Patent number: 7817698
    Abstract: The invention relates to a microfluidic dye laser including a pump light source configured to provide light having a pump light wavelength. The microfluidic dye laser also includes an elastomer substantially optically transparent at the pump light wavelength and at a microfluidic dye laser wavelength. A microfluidic channel configured to accept a fluidic dye is defined in the elastomer. An optical grating is formed in a single mode 3D waveguide in the microfluidic channel in order to provide a single mode microfluidic dye laser light as output in response to illumination with light from the pump light source. In another aspect, the invention features a method of tuning a wavelength of a microfluidic dye laser light by mechanically deforming the elastomeric laser chip to change the grating period in the optical cavity.
    Type: Grant
    Filed: August 9, 2007
    Date of Patent: October 19, 2010
    Assignee: California Institute of Technology
    Inventors: Zhenyu Li, Demetri Psaltis, Axel Scherer, Zhaoyu Zhang
  • Patent number: 7813016
    Abstract: A harmonic holography (H2) technique and system that combines holography and nonlinear optics that enables holographic recording of 3D images with femtosecond framing time are provided. The H2 technique records holograms with second harmonic (SH) signals scattered off specialized nanocrystals that are functionalized to label specific protein or other biomolecules in a living organism. The capability of generating second harmonic radiations is specific to materials with noncentrosymmetric crystalline structures only, and ?(2) vanishes for all other types of materials. Therefore, a sharp contrast is formed when particles of noncentrosymmetric structures are dispersed in a medium of other species, pumped at a fundamental frequency, and imaged at the second harmonic frequency. The new scheme described herein provides a sound basis for a new type of contrast microscopy with enormous potential in molecular biomedical imaging.
    Type: Grant
    Filed: November 21, 2007
    Date of Patent: October 12, 2010
    Assignee: California Institute of Technology
    Inventors: Ye Pu, Demetri Psaltis
  • Patent number: 7798164
    Abstract: A method of microfluidic control via localized heating includes providing a microchannel structure with a base region that is partially filled with a volume of liquid being separated from a gas by a liquid-gas interface region. The base region includes one or more physical structures. The method further includes supplying energy input to a portion of the one or more physical structures within the volume of liquid in a vicinity of the liquid-gas interface region to cause localized heating of the portion of the one or more physical structures. The method also includes transferring heat from the portion of the one or more physical structures to surrounding liquid in the vicinity of the liquid-gas interface region and generating an interphase mass transport at the liquid-gas interface region or across a gas bubble while the volume of liquid and the gas remain to be substantially at ambient temperature.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: September 21, 2010
    Assignee: California Institute of Technology
    Inventors: James Adleman, David A. Boyd, David G. Goodwin, Demetri Psaltis
  • Patent number: 7773227
    Abstract: An optofluidic microscope device is disclosed. The device includes a fluid channel having a surface and an object such as a bacterium or virus may flow through the fluid channel. Light imaging elements in the bottom of the fluid channel may be used to image the object.
    Type: Grant
    Filed: May 9, 2005
    Date of Patent: August 10, 2010
    Assignee: California Institute of Technology
    Inventors: Changhuei Yang, Demetri Psaltis