Patents by Inventor Himadri Sekhar Maiti

Himadri Sekhar Maiti 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: 8649650
    Abstract: The present invention provides a method of making rare earth (RE) doped optical fiber using BaO as co-dopant instead of Al or P commonly used for incorporation of the RE in silica glass by MCVD and solution doping technique. The method comprises deposition of particulate layer of GeO2 doped SiO2 with or without small P2O5 for formation of the core and solution doping by soaking the porous soot layer into an aqueous solution of RE and Ba containing salt. This is followed by dehydration and sintering of the soaked deposit, collapsing at a high temperature to produce the preform and drawing of fibers of appropriate dimension. The use of Ba-oxide enables to eliminate unwanted core-clad interface defect which is common in case of Al doped fibers. The fibers also show good RE uniformity, relatively low optical loss in the 0.6-1.6 ?m wavelength region and good optical properties suitable for their application in amplifiers, fiber lasers and sensor devices.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: February 11, 2014
    Assignees: Council of Scientific & Industrial Research, Department of Information Technology
    Inventors: Ranjan Sen, Anirban Dhar, Mukul Chandra Paul, Himadri Sekhar Maiti
  • Publication number: 20120201504
    Abstract: The present invention provides a method of making rare earth (RE) doped optical fiber using BaO as co-dopant instead of Al or P commonly used for incorporation of the RE in silica glass by MCVD and solution doping technique. The method comprises deposition of particulate layer of GeO2 doped SiO2 with or without small P2O5 for formation of the core and solution doping by soaking the porous soot layer into an aqueous solution of RE and Ba containing salt. This is followed by dehydration and sintering of the soaked deposit, collapsing at a high temperature to produce the preform and drawing of fibers of appropriate dimension. The use of Ba-oxide enables to eliminate unwanted core-clad interface defect which is common in case of Al doped fibers. The fibers also show good RE uniformity, relatively low optical loss in the 0.6-1.6 ?m wavelength region and good optical properties suitable for their application in amplifiers, fiber lasers and sensor devices.
    Type: Application
    Filed: March 29, 2010
    Publication date: August 9, 2012
    Inventors: Ranjan Sen, Anirban Dhar, Mukul Chandra Paul, Himadri Sekhar Maiti
  • Patent number: 7368405
    Abstract: The present invention relates to a process of making silicon-silicon carbide ceramic using biopreform derived from monocotyledonous caudex plant stem. The present invention also provides a silicon-silicon carbide ceramic made using a biopreform derived from monocotyledonous caudex plant stem.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: May 6, 2008
    Assignee: Council of Scientific and Industrial Research
    Inventors: Omprakash Chakrabarti, Himadri Sekhar Maiti, Rabindranath Mazumdar
  • Patent number: 7309425
    Abstract: The present invention relates to a process for the preparation of arsenic free water and an apparatus therefor. The present invention also relates to a porous ceramic useful for pressure filtration in order to produce arsenic free water. The present invention particularly relates to a process for preparing arsenic free (<10 ppb) water from arsenic contaminated ground water and apparatus therefor.
    Type: Grant
    Filed: August 15, 2005
    Date of Patent: December 18, 2007
    Assignee: Council of Scientific and Industrial Research
    Inventors: Sibdas Bandyopadhya, Dipali Kundu, Somendra Nath Roy, Bishnupada Ghosh, Himadri Sekhar Maiti
  • Patent number: 7014771
    Abstract: The present invention relates to a process for the preparation of arsenic free water and an apparatus therefor. The present invention also relates to a porous ceramic useful for pressure filtration in order to produce arsenic free water. The present invention particularly relates to a process for preparing arsenic free (<10 ppb) water from arsenic contaminated ground water and apparatus therefor.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: March 21, 2006
    Assignee: Council of Scientific and Industrial Research
    Inventors: Sibdas Bandyopadhyay, Dipali Kundu, Somendra Nath Roy, Bishnupada Ghosh, Himadri Sekhar Maiti
  • Publication number: 20040135275
    Abstract: The present invention relates to a process of making silicon-silicon carbide ceramic using biopreform derived from monocotyledonous caudex plant stem. The present invention also provides a silicon—silicon carbide ceramic made using a biopreform derived from monocotyledonous caudex plant stem.
    Type: Application
    Filed: December 30, 2002
    Publication date: July 15, 2004
    Applicant: Council of Scientific and Industrial Research
    Inventors: Omprakash Chakrabarti, Himadri Sekhar Maiti, Rabindranath Mazumdar
  • Publication number: 20040126561
    Abstract: A method of making biopreform from the stem of monocotyledonous caudex plant, that is suitable for liquid infiltration and gaseous transportation of materials, is disclosed. Wood from caudex stem of trees such as coconut (Cocos nucifera), palmyra palm (Borassus flabellifer), date palm (Phoenics dactylifera), is used as a precursor material which is transformed under simple pyrolitic conditions under self-generated ambient atmosphere to biopreform having microstructural features typical of a monocotyledonous caudex tree. The biopreform is capable of liquid infiltration and gaseous transportation processing of materials in an appreciably shorter processing periods, because of its preservation of the structural and anatomical features of the parent plants with high precision.
    Type: Application
    Filed: December 30, 2002
    Publication date: July 1, 2004
    Applicant: Council of Scientific and Industrial Research
    Inventors: Omprakash Chakrabarti, Himadri Sekhar Maiti, Rabindranath Mazumdar
  • Publication number: 20030183579
    Abstract: The present invention relates to a process for the preparation of arsenic free water and an apparatus therefor. The present invention also relates to a porous ceramic useful for pressure filtration in order to produce arsenic free water. The present invention particularly relates to a process for preparing arsenic free (<10 ppb) water from arsenic contaminated ground water and apparatus therefor.
    Type: Application
    Filed: March 29, 2002
    Publication date: October 2, 2003
    Inventors: Sibdas Bandyopadhya, Dipali Kundu, Somendra Nath Roy, Bishnupada Ghosh, Himadri Sekhar Maiti