Patents by Inventor Vishnu Vardhan Krishnamachari

Vishnu Vardhan Krishnamachari 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: 10739193
    Abstract: An electric circuit for a microscope includes a lock-in amplifier. The lock-in amplifier has an input for an input signal, an input for a reference signal, an output for an output signal and a bandwidth filter configured such that a low bandwidth frequency value and/or a high bandwidth frequency value is variably settable. A dynamic bandwidth controller is configured to receive at least one parameter of a current setting of the microscope as an input, and to control the low bandwidth frequency value and/or the high bandwidth frequency value of the lock-in amplifier as a function of the at least one parameter of the current setting of the microscope.
    Type: Grant
    Filed: October 10, 2016
    Date of Patent: August 11, 2020
    Assignee: LEICA MICROSYSTEMS CMS GMBH
    Inventor: Vishnu Vardhan Krishnamachari
  • Patent number: 10705356
    Abstract: A method for adjusting an intensity of a light beam in an optical arrangement includes passing the light beam through an acousto-optical tunable filter (AOTF). The intensity of the light beam is adjusted as a function of frequency and/or amplitude of a sound wave with which the AOTF is operated. The amplitude of the sound wave at a specified sound wave frequency is selected such that the amplitude is larger than would be required to achieve a first maximum diffraction efficiency for a specified wavelength or for a specified wavelength spectrum of the light beam. The amplitude of the sound wave is also selected such that a value of an integral of a product of the transmission function of the AOTF and the wavelength spectrum of the light beam is larger than at a value of the amplitude to be selected to achieve the first maximum.
    Type: Grant
    Filed: June 2, 2017
    Date of Patent: July 7, 2020
    Assignee: LEICA MICROSYSTEMS CMS GMBH
    Inventors: Manuel Kremer, Vishnu Vardhan Krishnamachari, Arnold Giske
  • Patent number: 10627285
    Abstract: A light/voltage converter circuit for converting intensity fluctuations of light into an alternating voltage measurement signal includes a photodiode configured to detect the light and a transformer comprising a primary coil and a secondary coil. The primary coil is connected in a series circuit to the photodiode, and the alternating voltage measurement signal is applied to the secondary coil. An electrical network is configured to block direct current and conduct alternating current. The electrical network is connected in parallel with the series circuit consisting of the primary coil of the transformer and the photodiode.
    Type: Grant
    Filed: March 1, 2017
    Date of Patent: April 21, 2020
    Assignee: LEICA MICROSYSTEMS CMS GMBH
    Inventors: Vishnu Vardhan Krishnamachari, Patric Mrawek, Bernd Widzgowski
  • Patent number: 10591356
    Abstract: The invention relates to a beam combiner for a microscope, in particular a scanning microscope, which receives at least a first illuminating light bundle and a second illuminating light bundle and combines them into a collinear output light bundle, the first illuminating light bundle and the second illuminating light bundle having the same illuminating light wavelength but a different polarization, in particular linear polarization. The beam combiner is embodied as an acousto-optic beam combiner and is constructed and operated in such a way that by interaction with at least one mechanical wave, both the first illuminating light bundle and the second illuminating light bundle are diffracted and are thereby directed into a common optical axis.
    Type: Grant
    Filed: September 3, 2014
    Date of Patent: March 17, 2020
    Assignee: Leica Microsystems CMS GmbH
    Inventors: Volker Seyfried, Vishnu Vardhan Krishnamachari
  • Publication number: 20190339500
    Abstract: An optical arrangement has an optical beam path for illuminating a sample space with a sequence of laser light pulses generated in a laser cycle, the optical arrangement. At least one laser light source is configured to generate the sequence of laser light pulses along the optical beam path. A wavelength-selective pulse picker is situated in the optical beam path and has, in a predefined illumination clock timing synchronizable with the laser light pulses, an open state in which the pulse picker is light-transparent to at least one laser light pulse towards the sample space. The open state has at least two different transmission states which differ with regard to their respective transmission spectrums, and wherein the two transmission states are switchable on and/or off independently of one another.
    Type: Application
    Filed: May 31, 2017
    Publication date: November 7, 2019
    Inventors: Bernd WIDZGOWSKI, Vishnu Vardhan KRISHNAMACHARI, Lars FRIEDRICH, Manuel KREMER, Arnold GISKE
  • Patent number: 10386303
    Abstract: A Raman microscopy imaging device (100) is described, having: a first laser light source (12) for emitting a first laser beam (16) having a first wavelength along a first light path (20); a second laser light source (44) for emitting a second laser beam (18) having a second wavelength, different from the first wavelength, along a second light path (22) physically separated from the first light path (20); a beam combining element (32) for collinearly combining the two laser beams (16, 18) in one shared light path (34) directed onto a sample; a detector (38) for sensing a measured signal on the basis of the two laser beams (16, 18) interacting with the sample; and an evaluation unit (40) for evaluating the measured signal sensed by the detector (38). According to the present invention the first laser light source (12) is embodied as a pulsed source, and the second laser light source (44) as a continuous source.
    Type: Grant
    Filed: November 19, 2014
    Date of Patent: August 20, 2019
    Assignee: Leica Microsystems CMS GmbH
    Inventors: Vishnu Vardhan Krishnamachari, Volker Seyfried, William C. Hay
  • Publication number: 20190086257
    Abstract: A light/voltage converter circuit for converting intensity fluctuations of light into an alternating voltage measurement signal includes a photodiode configured to detect the light and a transformer comprising a primary coil and a secondary coil. The primary coil is connected in a series circuit to the photodiode, and the alternating voltage measurement signal is applied to the secondary coil. An electrical network is configured to block direct current and conduct alternating current. The electrical network is connected in parallel with the series circuit consisting of the primary coil of the transformer and the photodiode.
    Type: Application
    Filed: March 1, 2017
    Publication date: March 21, 2019
    Inventors: Vishnu Vardhan KRISHNAMACHARI, Patric MRAWEK, Bernd WIDZGOWSKI
  • Patent number: 10132682
    Abstract: The invention relates to a microscope having an acousto-optic apparatus (13) that, with a mechanical wave that is characterized by a preferably adjustable frequency, removes from a polychromatic and collinear detected light bundle (18) portions of illuminated light, scattered and/or reflected at a sample, having an illuminating light wavelength associated with the frequency.
    Type: Grant
    Filed: September 3, 2014
    Date of Patent: November 20, 2018
    Assignee: Leica Microsystems CMS GmbH
    Inventors: Volker Seyfried, Vishnu Vardhan Krishnamachari
  • Patent number: 10132754
    Abstract: A device (10) for illuminating a sample (40) is described, having: at least one pulsed laser light source (12) for repeated emission of a first laser pulse along a first light path (14) and of a second laser pulse along a second light path (16) physically separated from the first light path; a superimposition element (32) for collinear superimposition of the two laser pulses in a shared light path (34); a delay stage (26) arranged in the first or the second light path (14, 16), for delaying one of the two laser pulses relative to the other laser pulse in such a way that the two laser pulses sent along the shared light path (34) onto the sample (40) exhibit a temporal superimposition; a shared chirp unit (36) arranged in the shared light path (34), for frequency-modifying influencing both of the first laser pulse and of the second laser pulse; and at least one separate chirp unit (18) arranged in the first light path (14), for frequency-modifying influencing only of the first laser pulse.
    Type: Grant
    Filed: November 19, 2014
    Date of Patent: November 20, 2018
    Assignee: Leica Microsystems CMS GmbH
    Inventors: Vishnu Vardhan Krishnamachari, Volker Seyfried, William C. Hay, Manuel Kremer
  • Publication number: 20180283939
    Abstract: An electric circuit for a microscope includes a lock-in amplifier. The lock-in amplifier has an input for an input signal, an input for a reference signal, an output for an output signal and a bandwidth filter configured such that a low bandwidth frequency value and/or a high bandwidth frequency value is variably settable. A dynamic bandwidth controller is configured to receive at least one parameter of a current setting of the microscope as an input, and to control the low bandwidth frequency value and/or the high bandwidth frequency value of the lock-in amplifier as a function of the at least one parameter of the current setting of the microscope.
    Type: Application
    Filed: October 10, 2016
    Publication date: October 4, 2018
    Inventor: Vishnu Vardhan Krishnamachari
  • Patent number: 9933686
    Abstract: The invention relates to an acousto-optic main beam splitter for a scanning microscope, which is embodied and intended to direct illuminating light having a preselected or preselectable illuminating light wavelength into an illumination beam path for illumination of a sample, and to direct detected light coming from a sample into a detection beam path.
    Type: Grant
    Filed: September 3, 2014
    Date of Patent: April 3, 2018
    Assignee: Leica Microsystems CMS GmbH
    Inventor: Vishnu Vardhan Krishnamachari
  • Patent number: 9909976
    Abstract: The invention relates to a method for investigating a sample, the sample being impinged upon by illuminating light, and detected light emerging from the sample being directed to a detector, and the illuminating light being directed through an acousto-optic component with which the impingement upon the sample by illuminating light can be temporarily interrupted.
    Type: Grant
    Filed: September 3, 2014
    Date of Patent: March 6, 2018
    Assignee: Leica Microsystems CMS GmbH
    Inventor: Vishnu Vardhan Krishnamachari
  • Publication number: 20170351073
    Abstract: A method for adjusting an intensity of a light beam in an optical arrangement includes passing the light beam through an acousto-optical tunable filter (AOTF). The intensity of the light beam is adjusted as a function of frequency and/or amplitude of a sound wave with which the AOTF is operated. The amplitude of the sound wave at a specified sound wave frequency is selected such that the amplitude is larger than would be required to achieve a first maximum diffraction efficiency for a specified wavelength or for a specified wavelength spectrum of the light beam. The amplitude of the sound wave is also selected such that a value of an integral of a product of the transmission function of the AOTF and the wavelength spectrum of the light beam is larger than at a value of the amplitude to be selected to achieve the first maximum.
    Type: Application
    Filed: June 2, 2017
    Publication date: December 7, 2017
    Inventors: Manuel Kremer, Vishnu Vardhan Krishnamachari, Arnold Giske
  • Publication number: 20160363537
    Abstract: A Raman microscopy imaging device (100) is described, having: a first laser light source (12) for emitting a first laser beam (16) having a first wavelength along a first light path (20); a second laser light source (44) for emitting a second laser beam (18) having a second wavelength, different from the first wavelength, along a second light path (22) physically separated from the first light path (20); a beam combining element (32) for collinearly combining the two laser beams (16, 18) in one shared light path (34) directed onto a sample; a detector (38) for sensing a measured signal on the basis of the two laser beams (16, 18) interacting with the sample; and an evaluation unit (40) for evaluating the measured signal sensed by the detector (38). According to the present invention the first laser light source (12) is embodied as a pulsed source, and the second laser light source (44) as a continuous source.
    Type: Application
    Filed: November 19, 2014
    Publication date: December 15, 2016
    Inventors: Vishnu Vardhan KRISHNAMACHARI, Volker SEYFRIED, William C. HAY
  • Publication number: 20160290928
    Abstract: A device (10) for illuminating a sample (40) is described, having: at least one pulsed laser light source (12) for repeated emission of a first laser pulse along a first light path (14) and of a second laser pulse along a second light path (16) physically separated from the first light path; a superimposition element (32) for collinear superimposition of the two laser pulses in a shared light path (34); a delay stage (26) arranged in the first or the second light path (14, 16), for delaying one of the two laser pulses relative to the other laser pulse in such a way that the two laser pulses sent along the shared light path (34) onto the sample (40) exhibit a temporal superimposition; a shared chirp unit (36) arranged in the shared light path (34), for frequency-modifying influencing both of the first laser pulse and of the second laser pulse; and at least one separate chirp unit (18) arranged in the first light path (14), for frequency-modifying influencing only of the first laser pulse.
    Type: Application
    Filed: November 19, 2014
    Publication date: October 6, 2016
    Inventors: Vishnu Vardhan KRISHNAMACHARI, Volker SEYFRIED, William C. HAY, Manuel KREMER
  • Publication number: 20160223882
    Abstract: The invention relates to an acousto-optic main beam splitter for a scanning microscope, which is embodied and intended to direct illuminating light having a preselected or preselectable illuminating light wavelength into an illumination beam path for illumination of a sample, and to direct detected light coming from a sample into a detection beam path.
    Type: Application
    Filed: September 3, 2014
    Publication date: August 4, 2016
    Inventor: Vishnu Vardhan KRISHNAMACHARI
  • Publication number: 20160223457
    Abstract: The invention relates to a method for investigating a sample, the sample being impinged upon by illuminating light, and detected light emerging from the sample being directed to a detector, and the illuminating light being directed through an acousto-optic component with which the impingement upon the sample by illuminating light can be temporarily interrupted.
    Type: Application
    Filed: September 3, 2014
    Publication date: August 4, 2016
    Inventor: Vishnu Vardhan KRISHNAMACHARI
  • Publication number: 20160216498
    Abstract: The invention relates to a microscope having an objective that focuses illuminating light to an illuminating light focus, and having a light-guiding fiber which transports the illuminating light and at whose end is arranged a fiber coupler that couples the illuminating light out of the light-guiding fiber and generates a preferably collimated illuminating light bundle. An element for modifying the shape of the illuminating light focus, which is prealigned relative to the illuminating light bundle to be coupled out, is arranged in or on the fiber coupler.
    Type: Application
    Filed: September 3, 2014
    Publication date: July 28, 2016
    Inventors: Volker SEYFRIED, Vishnu Vardhan KRISHNAMACHARI, Arnold GISKE
  • Publication number: 20160209270
    Abstract: The invention relates to a beam combiner for a microscope, in particular a scanning microscope, which receives at least a first illuminating light bundle and a second illuminating light bundle and combines them into a collinear output light bundle, the first illuminating light bundle and the second illuminating light bundle having the same illuminating light wavelength but a different polarization, in particular linear polarization. The beam combiner is embodied as an acousto-optic beam combiner and is constructed and operated in such a way that by interaction with at least one mechanical wave, both the first illuminating light bundle and the second illuminating light bundle are diffracted and are thereby directed into a common optical axis.
    Type: Application
    Filed: September 3, 2014
    Publication date: July 21, 2016
    Inventors: Volker SEYFRIED, Vishnu Vardhan KRISHNAMACHARI
  • Publication number: 20160202121
    Abstract: The invention relates to a microscope having an acousto-optic apparatus (13) that, with a mechanical wave that is characterized by a preferably adjustable frequency, removes from a polychromatic and collinear detected light bundle (18) portions of illuminated light, scattered and/or reflected at a sample, having an illuminating light wavelength associated with the frequency.
    Type: Application
    Filed: September 3, 2014
    Publication date: July 14, 2016
    Inventors: Volker SEYFRIED, Vishnu Vardhan KRISHNAMACHARI