Patents by Inventor Tiejun Chang

Tiejun Chang 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).

  • Patent number: 11944729
    Abstract: A liftable aroma diffuser includes a shell assembly having a storage space and a first opening communicated with the storage space; a lifting mechanism slidably connected to the shell assembly and including a lifting main body and a fragrance storage element arranged on the lifting main body and configured to bear a fragrance element; and a drive assembly arranged on the shell assembly and connected to the lifting main body and configured to drive the lifting mechanism to slide relative to the shell assembly. The lifting mechanism is able to change between a first received state of being received in the storage space and a first extended state of at least partially extending out of the storage space from the first opening.
    Type: Grant
    Filed: May 15, 2023
    Date of Patent: April 2, 2024
    Inventor: Tiejun Chang
  • Patent number: 7379652
    Abstract: Techniques for detecting optical spectral properties of a target are described. The technique includes providing an optical carrier which has an optical frequency bandwidth which is narrow compared to the width of the narrowest spectral feature of the target to be determined. This optical carrier is then electro-optically modulated with an RF frequency chirp, creating an optical chirp probe beam with a frequency chirped optical spectrum having upper and lower frequency chirped sidebands that have amplitudes sufficient to be detected at a detector. The sidebands are frequency bands arranged symmetrically around the optical carrier frequency. The attributes of a sideband include a start frequency, bandwidth and chirp rate. A probe beam is generated with the sidebands and directed onto a target having a physical property with optical frequency dependence. An optical response signal resulting from an interaction between the probe beam and the target is detected.
    Type: Grant
    Filed: April 14, 2006
    Date of Patent: May 27, 2008
    Assignee: Montana State University
    Inventors: Zachary Cole, Randy R. Reibel, Krishna Mohan Rupavatharam, William R. Babbitt, Kristian D. Merkel, Tiejun Chang
  • Publication number: 20070285762
    Abstract: Techniques for reconfiguring spectral features stored in a medium based on a two-state atomic system with transition dipole moment ? includes causing a chirp to pass into the medium. The chirp includes a monochromatic frequency that varies in time by a chirp rate ? over a frequency band BR during a time interval TR. The amplitude AR of the chirp is constant over BR and equal to AR=(hbar/??)?{square root over ((? ln [2/?]))}, The term hbar is reduced Plank's constant, ln is a natural logarithm function, and ? is a ratio of a circumference of a circle to a diameter of the circle. For ?<<1, the atomic-state populations in the two states are inverted. For ?=1, prior atomic-state populations are erased, with final populations equal in the two states, regardless of populations before erasure.
    Type: Application
    Filed: July 14, 2006
    Publication date: December 13, 2007
    Inventors: Tiejun Chang, Mingzhen Tian, William Babbitt, Kristian Merkel
  • Patent number: 7307781
    Abstract: Techniques for reconfiguring spectral features stored in a medium based on a two-state atomic system with transition dipole moment ? includes causing a chirp to pass into the medium. The chirp includes a monochromatic frequency that varies in time by a chirp rate ? over a frequency band BR during a time interval TR. The amplitude AR of the chirp is constant over BR and equal to AR=(hbar/??)?{square root over ((? ln [2/?]))}, The term hbar is reduced Plank's constant, ln is a natural logarithm function, and ? is a ratio of a circumference of a circle to a diameter of the circle. For ?<<1, the atomic-state populations in the two states are inverted. For ?=1, prior atomic-state populations are erased, with final populations equal in the two states, regardless of populations before erasure.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: December 11, 2007
    Assignee: Montana State University
    Inventors: Tiejun Chang, Mingzhen Tian, William R. Babbitt, Kristian D. Merkel
  • Patent number: 7265712
    Abstract: Techniques for analog processing of high time-bandwidth-product (TBP) signals use a material with an inhomogeneously broadened absorption spectrum including multiple homogeneously broadened absorption lines. A first set of signals on optical carriers interact in the material during a time on the order of a phase coherence time of the homogeneously broadened absorption lines to record an analog interaction absorption spectrum. Within a time on the order of a population recovery time for a population of optical absorbers it the material, the interaction absorption spectrum in the material is read to produce a digital readout signal. The readout signal represents a temporal map of the interaction absorption spectrum, and includes frequency components that relate to a processing result of processing the first set of signals. The techniques allow processing of RADAR signals for improved range resolution to a target, as well as speed of the target, among other uses.
    Type: Grant
    Filed: May 12, 2003
    Date of Patent: September 4, 2007
    Assignee: Montana State University
    Inventors: Kristian Merkel, Zachary Cole, Krishna Rupavatharam, William R. Babbitt, Kelvin Wagner, Tiejun Chang
  • Publication number: 20070171407
    Abstract: Techniques for detecting optical spectral properties of a target are described. The technique includes providing an optical carrier which has an optical frequency bandwidth which is narrow compared to the width of the narrowest spectral feature of the target to be determined. This optical carrier is then electro-optically modulated with an RF frequency chirp, creating an optical chirp probe beam with a frequency chirped optical spectrum having upper and lower frequency chirped sidebands that have amplitudes sufficient to be detected at a detector. The sidebands are frequency bands arranged symmetrically around the optical carrier frequency. The attributes of a sideband include a start frequency, bandwidth and chirp rate. A probe beam is generated with the sidebands and directed onto a target having a physical property with optical frequency dependence. An optical response signal resulting from an interaction between the probe beam and the target is detected.
    Type: Application
    Filed: April 14, 2006
    Publication date: July 26, 2007
    Inventors: Zachary Cole, Randy Reibel, Krishna Rupavatharam, William Babbitt, Kristian Merkel, Tiejun Chang
  • Patent number: 7145713
    Abstract: Techniques for recovering optical spectral features include receiving a detected time series that represents a temporally varying intensity of an optical signal. The optical signal is formed in response to an interaction between a target optical spectrum and a chirped optical field. The chirped optical field is an optical field that has a monochromatic frequency that varies in time. The target optical spectrum is an optical frequency dependent optical property of a material or device. A phase correction factor is determined based only on one or more properties of the chirped optical field. The detected time series is corrected based on the phase correction factor to produce an output time series that reproduces in time a shape of the target spectrum in frequency. These techniques allow for fast measurement of spectral features and eliminate the need for prior knowledge of the target optical spectrum to adjust the chirp rate.
    Type: Grant
    Filed: July 12, 2005
    Date of Patent: December 5, 2006
    Assignee: Montana State University
    Inventors: Tiejun Chang, Mingzhen Tian, William R. Babbitt, Kristian Merkel
  • Publication number: 20060049981
    Abstract: Techniques for analog processing of high time-bandwidth-product (TBP) signals use a material with an inhomogeneously broadened absorption spectrum including multiple homogeneously broadened absorption lines. A first set of signals on optical carriers interact in the material during a time on the order of a phase coherence time of the homogeneously broadened absorption lines to record an analog interaction absorption spectrum. Within a time on the order of a population recovery time for a population of optical absorbers it the material, the interaction absorption spectrum in the material is read to produce a digital readout signal. The readout signal represents a temporal map of the interaction absorption spectrum, and includes frequency components that relate to a processing result of processing the first set of signals. The techniques allow processing of RADAR signals for improved range resolution to a target, as well as speed of the target, among other uses.
    Type: Application
    Filed: May 12, 2003
    Publication date: March 9, 2006
    Inventors: Kristian Merkel, Zachary Cole, Krishna Rupavatharam, William Babbitt, Kelvin Wagner, Tiejun Chang
  • Publication number: 20060012797
    Abstract: Techniques for recovering optical spectral features include receiving a detected time series that represents a temporally varying intensity of an optical signal. The optical signal is formed in response to an interaction between a target optical spectrum and a chirped optical field. The chirped optical field is an optical field that has a monochromatic frequency that varies in time. The target optical spectrum is an optical frequency dependent optical property of a material or device. A phase correction factor is determined based only on one or more properties of the chirped optical field. The detected time series is corrected based on the phase correction factor to produce an output time series that reproduces in time a shape of the target spectrum in frequency. These techniques allow for fast measurement of spectral features and eliminate the need for prior knowledge of the target optical spectrum to adjust the chirp rate.
    Type: Application
    Filed: July 12, 2005
    Publication date: January 19, 2006
    Inventors: Tiejun Chang, Mingzhen Tian, William Babbitt, Kristian Merkel