Patents by Inventor Raja A Ahmad
Raja A Ahmad 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: 20240126009Abstract: Described herein are systems, methods, and articles of manufacture for high back-scattering waveguides (e.g., optical fibers) and sensors employing high back-scattering optical fibers. Briefly described, one embodiment comprises a high back-scattering fiber, or enhanced scattering fiber or “ESF,” that features resistance specifications that remain intact over lengths of fiber in excess of 1 m, or preferably >100 m, or preferably >1 km, wherein the reflectivity of the ESFs may be precisely tuned within a range from ?100 dB/mm to ?70 dB/mm, and wherein the enhanced scattering may be spatially continuous or, alternatively, may be at discrete locations spaced apart by 100 microns to >10 m.Type: ApplicationFiled: February 14, 2022Publication date: April 18, 2024Applicant: OFS FITEL, LLCInventors: Raja A Ahmad, Paul S Westbrook
-
Patent number: 11933600Abstract: An extended length of optical fiber having an offset core with an inscribed Bragg grating is used a distributed sensor in combination with an optical frequency domain reflectometer (OFDR) to enable measurement small-scale (e.g., sub-millimeter) contortions and forces as applied to the fiber. The offset core may be disposed in a spiral configuration around the central axis of the optical fiber to improve the spatial resolution of the measurement. A reference surface exhibit a predetermined texture (in the form of a series of corrugations, for example, that may be periodic or aperiodic, as long as known a priori) is disposed adjacent to a longitudinal portion of the sensor fiber. The application of a force to the combination of the plate and the fiber creates a local strain in the grating formed along the offset core of the fiber that results in a shift in the Bragg wavelength of the grating.Type: GrantFiled: November 18, 2019Date of Patent: March 19, 2024Assignee: OFS FITEL, LLCInventors: Raja A Ahmad, Kenneth S Feder, Wing Ko, Paul S Westbrook
-
Publication number: 20230137926Abstract: A system for sensing microbends and micro-deformations in three-dimensional space is based upon a distributed length optical fiber formed to include a group of offset cores disposed in a spiral configuration along the length of the fiber, each core including a fiber Bragg grating that exhibits the same Bragg wavelength. A micro-scale local deformation of the multicore fiber produces a local shift in the Bragg wavelength, where the use of multiple cores allows for a complete micro-scale modeling of the local deformation. Sequential probing of each core allows for optical frequency domain reflectometry (OFDR) allows for reconstruction of a given three-dimensional shape, delineating location and size of various microbends and micro-deformations.Type: ApplicationFiled: March 15, 2021Publication date: May 4, 2023Applicant: OFS Fitel, LLCInventors: Raja A Ahmad, Paul S Westbrook
-
Publication number: 20220057586Abstract: A photoinduced refractive index-changing material is coupled directly to both a first port and a second port. An optical interconnect structure (for optically coupling the first port to the second port) is formable in the photoinduced refractive index-changing material by selectively exposing a portion of the photoinduced refractive index-changing material. The selective exposure induces a refractive index change in the photoinduced refractive index-changing material. The change in refractive index provides the waveguiding properties of the optical interconnect structure.Type: ApplicationFiled: December 16, 2019Publication date: February 24, 2022Applicant: OFS Fitel, LLCInventors: Raja A Ahmad, David J DiGiovanni
-
Publication number: 20210389121Abstract: An extended length of optical fiber having an offset core with an inscribed Bragg grating is used a distributed sensor in combination with an optical frequency domain reflectometer (OFDR) to enable measurement small-scale (e.g., sub-millimeter) contortions and forces as applied to the fiber. The offset core may be disposed in a spiral configuration around the central axis of the optical fiber to improve the spatial resolution of the measurement. A reference surface exhibit a predetermined texture (in the form of a series of corrugations, for example, that may be periodic or aperiodic, as long as known a priori) is disposed adjacent to a longitudinal portion of the sensor fiber. The application of a force to the combination of the plate and the fiber creates a local strain in the grating formed along the offset core of the fiber that results in a shift in the Bragg wavelength of the grating.Type: ApplicationFiled: November 18, 2019Publication date: December 16, 2021Applicant: OFS FITEL, LLCInventors: Raja A Ahmad, Kenneth S Feder, Wing Ko, Paul S Westbrook
-
Patent number: 11156769Abstract: A higher-order mode (HOM) fiber is configured as a polarization-maintaining fiber by including a pair of stress rods at a location within the cladding layer that provides for a sufficient degree of birefringence without unduly comprising the spatial mode profile of the propagating higher-order modes. An optical imaging system utilizing polarization-maintaining HOM fiber allows for different wavelength probe signals to be directed into different modes, useful in applications such as STED microscopy, 2D sensing, and the like.Type: GrantFiled: April 15, 2019Date of Patent: October 26, 2021Assignee: OFS FITEL, LLCInventors: Raja A Ahmad, Man F Yan, David J DiGiovanni
-
Publication number: 20190243061Abstract: A higher-order mode (HOM) fiber is configured as a polarization-maintaining fiber by including a pair of stress rods at a location within the cladding layer that provides for a sufficient degree of birefringence without unduly comprising the spatial mode profile of the propagating higher-order modes. An optical imaging system utilizing polarization-maintaining HOM fiber allows for different wavelength probe signals to be directed into different modes, useful in applications such as STED microscopy, 2D sensing, and the like.Type: ApplicationFiled: April 15, 2019Publication date: August 8, 2019Applicant: OFS Fitel, LLCInventors: Raja A. Ahmad, Man F. Yan, David J. DiGiovanni
-
Patent number: 10261246Abstract: A higher-order mode (HOM) fiber is configured as a polarization-maintaining fiber by including a pair of stress rods at a location within the cladding layer that provides for a sufficient degree of birefringence without unduly comprising the spatial mode profile of the propagating higher-order modes. Long-period gratings are used as mode couplers at the input and output of the PM-HOM fiber, where the gratings are formed by exposing areas of the core region orthogonal to the position of the stress rods. The diameter of the stress rods (D) and displacement of the rods from the center of the core region (R1) are controlled to yield a configuration with an acceptable birefringence and polarization extinction ratio (PER) within the HOM fiber, even in situations where the fiber is bent (a bend radius less than 50 cm).Type: GrantFiled: March 30, 2017Date of Patent: April 16, 2019Assignee: OFS FITEL, LLCInventors: Raja A Ahmad, Man F Yan, David J DiGiovanni
-
Patent number: 9704470Abstract: A self tuned apparatus (100) for active noise control includes a first transducer (105) and a second transducer (110), a noise controlling module (115), a power amplifier (120) and a first loudspeaker (125) and a second loudspeaker (130) coupled to the power amplifier (120). The noise controlling module (115) is coupled to the first transducer (105) and the second transducer (110). The power amplifier (120) is coupled to the noise controlling module (115). Particularly, the noise controlling module (115) employs at least one control algorithm.Type: GrantFiled: October 1, 2014Date of Patent: July 11, 2017Assignee: UNIVERSITI PUTRA MALAYSIAInventors: Mohd Kamil Raja Ahmad Raja, Abdulredha Sahib Mouayad, Ghasemi Dehkordi Sepehr
-
Publication number: 20160240184Abstract: A self tuned apparatus (100) for active noise control includes a first transducer (105) and a second transducer (110), a noise controlling module (115), a power amplifier (120) and a first loudspeaker (125) and a second loudspeaker (130) coupled to the power amplifier (120). The noise controlling module (115) is coupled to the first transducer (105) and the second transducer (110). The power amplifier (120) is coupled to the noise controlling module (115). Particularly, the noise controlling module (115) employs at least one control algorithm.Type: ApplicationFiled: October 1, 2014Publication date: August 18, 2016Inventors: Mohd Kamil Raja Ahmad RAJA, Abdulredha Sahib MOUAYAD, Ghasemi Dehkordi SEPEHR
-
Patent number: 7638661Abstract: Use of a viscosity increasing component (ii) in provided in a composition (i) of a diesel fuel for the purpose of: improving the vehicle tractive effort (VTE) and/or acceleration performance of a compression ignition engine or a vehicle powered by such an engine, into which engine the composition (i) is introduced, or mitigating decrease in the vehicle tractive effort (VTE) and/or acceleration performance, in the case of a diesel fuel composition (i) to which an additional component (iii) is introduced for the purpose of improving the emissions performance, of a compression ignition engine or a vehicle powered by such an engine, into which engine the composition (i) is introduced.Type: GrantFiled: December 1, 2004Date of Patent: December 29, 2009Assignee: Shell Oil CompanyInventors: John Nicholas Davenport, Raja Ahmad Sani Raja Salim, Trevor Stephenson, Nigel Peter Tait
-
Publication number: 20060112614Abstract: Use of a viscosity increasing component (ii) in provided in a composition (i) of a diesel fuel for the purpose of: improving the vehicle tractive effort (VTE) and/or acceleration performance of a compression ignition engine or a vehicle powered by such an engine, into which engine the composition (i) is introduced, or mitigating decrease in the vehicle tractive effort (VTE) and/or acceleration performance, in the case of a diesel fuel composition (i) to which an additional component (iii) is introduced for the purpose of improving the emissions performance, of a compression ignition engine or a vehicle powered by such an engine, into which engine the composition (i) is introduced.Type: ApplicationFiled: December 1, 2004Publication date: June 1, 2006Inventors: John Davenport, Raja Ahmad Raja Salim, Trevor Stephenson, Nigel Tait