Patents by Inventor Mukul Chandra Paul
Mukul Chandra Paul 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).
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Patent number: 8649650Abstract: 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: GrantFiled: March 29, 2010Date of Patent: February 11, 2014Assignees: Council of Scientific & Industrial Research, Department of Information TechnologyInventors: Ranjan Sen, Anirban Dhar, Mukul Chandra Paul, Himadri Sekhar Maiti
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Publication number: 20120201504Abstract: 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: ApplicationFiled: March 29, 2010Publication date: August 9, 2012Inventors: Ranjan Sen, Anirban Dhar, Mukul Chandra Paul, Himadri Sekhar Maiti
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Patent number: 6889528Abstract: The present invention discloses a process for making rare earth (RE) doped optical fiber by using RE oxide coated silica nanoparticles as the precursor material, more particularly the method of the present invention involves preparation of stable dispersions (sol) of RE oxide coated silica nanoparticles at ambient temperature and applying a thin coating on the inner surface of silica glass tube following dip coating technique or any other conventional methods, of the said silica sol containing suitable dopants selected from Ge, Al, P, etc.Type: GrantFiled: October 22, 2001Date of Patent: May 10, 2005Assignees: Council of Scientific & Industrial Research, Bar-Ilan UniversityInventors: Ranjan Sen, Minati Chatterjee, Milan Kanti Naskar, Mrinmay Pal, Mukul Chandra Paul, Shyamal Kumar Bhadra, Kamal Dasgupta, Dibyendu Ganguli, Tarun Bandyopadhyay, Aharon Gedanken
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Patent number: 6851281Abstract: The present invention provides a method of fabricating rare earth doped preforms and optical fibers by a combination of modified chemical vapor deposition (MCVD) process and solution doping technique said MCVD process is used to develop matched or depressed clad structure inside a silica glass substrate tube followed by deposition of porous silica soot layer containing GeO2, P2O5 or such refractive index modifiers by the backward deposition method for formation of the core and presintering the deposited particulate layer by backward pass with flow of GeCl4 and/or corresponding dopant halides, soaking the porous soot layer into an alcoholic/aqueous solution of RE-salts containing codopants such as AlCl3 in definite proportion, drying, oxidation, dehydration and sintering of the RE containing porous deposit and by collapsing at a high temperature to produce the preform followed by drawing the fibers by known technique to produce fibers with suitable core-clad dimensions and geometry.Type: GrantFiled: March 27, 2002Date of Patent: February 8, 2005Assignee: Council of Scientific and Industrial ResearchInventors: Ranjan Sen, Mrinmay Pal, Mukul Chandra Paul, Shyamal Kumar Bhadra, Somesh Chatterjee, Kamal Dasgupta
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Publication number: 20040187524Abstract: The present invention discloses a process for making rare earth (RE) doped optical fibre by using RE oxide coated silica nanoparticles as the precursor materia, more particularly the method of the present invention involves preparation of stable dispersions (sol) of RE oxide coated silica nanoparticles at ambient temperature and applying a thin coating on the inner surface of silica glass tube following dip coating technique or any other conventional methods, of the said silica sol containing suitable dopants selected from Ge, Al, P, etc.Type: ApplicationFiled: October 22, 2001Publication date: September 30, 2004Applicant: COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCHInventors: Ranjan Sen, Minati Chatterjee, Milan Kanti Naskar, Mrinmay Pal, Mukul Chandra Paul, Shyamal Kumar Bhadra, Kamal Dasgupta, Dibyendu Ganguli, Tarun Bandyopadhyay, Aharon Gedanken
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Patent number: 6751990Abstract: The present invention provides an improved process for making rare earth doped preforms and fibers by a combination of MCVD technique and solution doping method, said method comprising developing matched or depressed clad structure inside a silica glass substrate tube followed by deposition of unsintered particulate layer containing GeO2 and P2O5 for formation of the core and solution doping by soaking the porous soot layer into an alcoholic/aqueous solution of RE-salts containing co-dopants like AlCl3/Al(NO3)3 in definite proportion, controlling the porosity of the soot, dipping period, strength of the solution and the proportion of the codopants to achieve the desired RE ion concentration in the core and minimize the core clad boundary defects and followed by drying, oxidation, dehydration and sintering of the RE containing porous deposit and collapsing at a high temperature to produce the preform and overcladding with silica tubes of suitable dimensions and fiber drawing to produce fibers.Type: GrantFiled: March 6, 2001Date of Patent: June 22, 2004Assignee: Council of Scientific and Industrial ResearchInventors: Tarun Bandyopadhyay, Ranjan Sen, Shyamal Kumar Bhadra, Kamal Dasgupta, Mukul Chandra Paul
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Publication number: 20030182970Abstract: The present invention provides a method of fabricating rare earth doped preforms and optical fibres by a combination of modified chemical vapour deposition (MCVD) process and solution doping technique said MCVD process is used to develop matched or depressed clad structure inside a silica glass substrate tube followed by deposition of porous silica soot layer containing GeO2, P2O5 or such refractive index modifiers by the backward deposition method for formation of the core and presintering the deposited particulate layer by backward pass with flow of GeCl4 and/or corresponding dopant halides, soaking the porous soot layer into an alcoholic/aqueous solution of RE-salts containing codopants such as AlCl3 in definite proportion, drying, oxidation, dehydration and sintering of the RE containing porous deposit and by collapsing at a high temperature to produce the preform followed by drawing the fibres by known technique to produce fibres with suitable core-clad dimensions and geometry.Type: ApplicationFiled: March 27, 2002Publication date: October 2, 2003Applicant: COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCHInventors: Ranjan Sen, Mrinmay Pal, Mukul Chandra Paul, Shyamal Kumar Bhadra, Somesh Chatterjee, Kamal Dasgupta
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Publication number: 20020124601Abstract: The present invention provides an improved process for making rare earth doped preforms and fibers by a combination of MCVD technique and solution doping method, said method comprising developing matched or depressed clad structure inside a silica glass substrate tube followed by deposition of unsintered particulate layer containing GeO2 and P2O5 for formation of the core and solution doping by soaking the porous soot layer into an alcoholic/aqueous solution of RE-salts containing co-dopants like AlCl3/Al(NO3)3 in definite proportion, controlling the porosity of the soot, dipping period, strength of the solution and the proportion of the codopants to achieve the desired RE ion concentration in the core and minimize the core clad boundary defects and followed by drying, oxidation, dehydration and sintering of the RE containing porous deposit and collapsing at a high temperature to produce the preform and overdladding with silica tubes of suitable dimensions and fiber drawing to produce fibers.Type: ApplicationFiled: March 6, 2001Publication date: September 12, 2002Inventors: Tarun Bandyopadhyay, Ranjan Sen, Shyamal Kumar Bhadra, Kamal Dasgupta, Mukul Chandra Paul