Patents Assigned to E-Tek Dynamics, Inc.
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Patent number: 6556765Abstract: A planar optical attenuator designed as a MEMS structure has a mirror opposite an input and an output waveguide, and a TAB actuator for lateral displacement of the mirror relative to the input port and/or output port. The effective reflectivity of the mirror is variable as a function of the lateral location on the mirror. The optical attenuation is varied by varying the location on the mirror at which the optical beam is reflected.Type: GrantFiled: April 17, 2001Date of Patent: April 29, 2003Assignee: E-Tek Dynamics, Inc.Inventors: Brian Lee Heffner, Gokul Krishnan
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Publication number: 20020150378Abstract: A planar optical attenuator designed as a MEMS structure has a mirror opposite an input and an output waveguide, and a TAB actuator for lateral displacement of the mirror relative to the input port and/or output port. The effective reflectivity of the mirror is variable as a function of the lateral location on the mirror. The optical attenuation is varied by varying the location on the mirror at which the optical beam is reflected.Type: ApplicationFiled: April 17, 2001Publication date: October 17, 2002Applicant: E-Tek Dynamics, Inc.Inventors: Brian Lee Heffner, Gokul Krishnan
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Publication number: 20020149850Abstract: A tunable optical notch filter employing a Fabry-Perot etalon has a first partially reflective mirror and a second mirror with variable effective reflectivity. Both the gap of the etalon and the effective reflectivity of the second mirror can be controlled, e.g. by TAB actuators, enabling a control of the central wavelength and the depth (loss) of the notch of the spectral response of the filter.Type: ApplicationFiled: April 17, 2001Publication date: October 17, 2002Applicant: E-Tek Dynamics, Inc.Inventors: Brian Lee Heffner, Gokul Krishnan
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Publication number: 20020146210Abstract: Optical devices, such as couplers, isolators and filters, are important building blocks in most WDM systems, within which light from a fiber is collimated, processed, and then focused onto another fiber. Unfortunately, during the processing of the light the beam gets walked-off from its initial path. In order for the light to fully couple between the fibers it is imperative that this walk-off be accounted for. Conventional systems simply mount the focusing lens and output ferrule offset from the collimating lens and input ferrule to ensure good coupling. However, there are several advantages to positioning the collimating lens coaxial with the focusing lens. Accordingly, the present invention relates to a method for optically coupling fibers with coaxial lenses by rotating an angle polished end face of at least one (preferably two) of the ferrules and lenses relative to the other ferrules and lenses. A greater range of positions is obtained when two of the ferrule and/or the lens are rotated.Type: ApplicationFiled: April 9, 2001Publication date: October 10, 2002Applicant: E-Tek Dynamics, Inc.Inventor: Warren Hale Lewis
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Patent number: 6317250Abstract: A method and apparatus for optically isolating multiple core optical fibers while at the same time substantially reducing polarization mode dispersion, is disclosed. A multiple core fiber is optically coupled to optical birefringent elements, reciprocal and non-reciprocal rotators, and through a lens assembly to a multiple core optical fiber output.Type: GrantFiled: September 12, 2000Date of Patent: November 13, 2001Assignee: E-Tek Dynamics, Inc.Inventors: Kejian Guan, Kok Wai Chang
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Patent number: 6249625Abstract: The present invention provides for a joined optical fiber subassembly having first, second and third sections. The first section has a plurality of separate optical fibers with each optical fiber having a core and cladding. The second section, which adjoins the first section, has the optical fibers joined so that a single cladding encloses the cores of the optical fibers. The third section, which adjoins the second section, has the single cladding enclosing the cores of the optical fibers. With the joined optical fiber subassembly as a constituent element, a subunit which can be used in many fiberoptic devices can be created.Type: GrantFiled: June 28, 1999Date of Patent: June 19, 2001Assignee: E-Tek Dynamics, Inc.Inventor: Jing-Jong Pan
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Patent number: 6246518Abstract: The isolator core having a walk-off crystal, a non-reciprocal rotator coupled to the walk-off crystal, and a reciprocal rotator coupled to the walk-off crystal.Type: GrantFiled: March 25, 1999Date of Patent: June 12, 2001Assignee: E-Tek Dynamics, Inc.Inventors: Kok Wai Chang, Kejian Guan
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Patent number: 6240220Abstract: A fiber optic package and methods for varying the tension within a fiber Bragg grating or other fiber-based optical device subjects a fiber (having the fiber Bragg grating written therein) to a controlled strain. The resulting strain in the fiber produces a desired and predetermined change in the grating wavelength.Type: GrantFiled: July 29, 1998Date of Patent: May 29, 2001Assignee: E-Tek Dynamics, Inc.Inventors: Jing-Jong Pan, Feng-Qing Zhou
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Patent number: 6212305Abstract: An optical isolator has a sleeve with a longitudinal channel, a pair of optical fibers in the longitudinal channel, a first, second and third birefringent crystals, a GRIN lens, a Faraday rotator and a mirror element. The first birefringent crystal covers the end facet of one of the pair of optical fibers, and the second and third birefringent crystals cover the end facet of the other of the pair of optical fibers. The GRIN lens has first and second end faces with the first end face proximate the first, second and third birefringent crystals. The Faraday rotator is located between the mirror element and the second end face of the GRIN lens. Light in one direction from a first optical fiber of the pair passes through, and back from, the first, second and third birefringent crystals, the GRIN lens, the Faraday rotator and the mirror element into a second optical fiber of the pair.Type: GrantFiled: June 28, 1999Date of Patent: April 3, 2001Assignee: E-Tek Dynamics, Inc.Inventor: Jing-Jong Pan
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Patent number: 6198858Abstract: A fiberoptic coupler capable of many functions is presented. The basic fiberoptic coupler has a first sleeve, a second sleeve, a first collimating GRIN or conventional lens, and a second collimating GRIN or conventional lens. The first sleeve holds end sections of two or more input optical fibers along the longitudinal axis of the sleeve. The second sleeve holds an end section of at least one output optical fiber. The end face of the second sleeve faces the first sleeve end face. The first collimating GRIN or conventional lens in front of the first sleeve end face collimates light signals from the input optical fibers and the second collimating GRIN or conventional lens in front of the second sleeve end face focusses light signals from at least one of the input optical fibers into the single output fiber, or at least one of the output optical fibers. With only one output fiber the coupler operates as a combiner.Type: GrantFiled: December 21, 1999Date of Patent: March 6, 2001Assignee: E-Tek Dynamics, Inc.Inventors: Jing-Jong Pan, Ming Shih, Jingyu Xu
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Patent number: 6195479Abstract: A polarization-insensitive fiberoptic reflective variable aftenuator and on-off switch is provided. The device has a sleeve holding a pair of optical fibers, a first, second and third birefringent crystals, a collimating GRIN lens, a liquid crystal cell and a mirror element. The first birefringent crystal is fixed over an end facet of one of the optical fiber pair, and the second and third birefringent crystals are fixed over an end facet of the other of the optical fiber pair. The GRIN lens has a first end face proximate the first, second and third birefringent crystals and the liquid crystal cell is located between the mirror element and a second end face of the GRIN lens. Responsive to preselected voltages applied to its electrical terminals, the liquid crystal cell is in a first state or a second state.Type: GrantFiled: June 28, 1999Date of Patent: February 27, 2001Assignee: E-Tek Dynamics, Inc.Inventor: Jing-Jong Pan
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Patent number: 6181846Abstract: A fiberoptic liquid crystal on-off switch and variable attenuator is provided. The end facets of two optical fiber cores in a sleeve, a birefringent crystal, a quarter-pitch GRIN lens, a liquid crystal cell and a mirror element are arranged and oriented with respect to each other so that light from the first optical fiber core passes through, and back from, the first birefringent crystal, the GRIN lens, the liquid crystal cell and the mirror element into the second optical fiber core when the liquid crystal cell is in a first state. When the liquid crystal cell is in an opposite second state, light from the first optical fiber core passes through, and back from, the first birefringent crystal, the GRIN lens, the liquid crystal cell and the mirror element, but not into the second optical fiber core.Type: GrantFiled: June 28, 1999Date of Patent: January 30, 2001Assignee: E-Tek Dynamics, Inc.Inventor: Jing-Jong Pan
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Patent number: 6181851Abstract: The invention provides a package which varies the tension within a fiber Bragg grating (or other fiber-based optical device) by resilient deflection of a fiber support member through differential thermal expansion, thereby allowing the temperature/tension characteristics of the package to be tailored so as to provide the desired optical characteristics throughout a wide temperature range. The fiber tension/temperature correlation may be tailored using the linear coefficient of expansion of two different materials, by varying the resilient flexibility of a beam supporting the fiber, by varying a length of an arm extending from the beam to the fiber, by varying the resilient strength of the arm, and the like. By relying on the resilient deformation of a flexible fiber support structure, the present invention provides a large number of degrees of freedom within the package design parameters.Type: GrantFiled: May 1, 1998Date of Patent: January 30, 2001Assignee: E-Tek Dynamics, Inc.Inventors: Jing-Jong Pan, Jian Chen, Pan Ma
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Patent number: 6148129Abstract: The present invention provides for a fiber optic coupler of first and second optic fibers formed by a length of the two fibers. The first optic fiber along the length has a different core diameter than that of the second optic fiber. At the both ends of the length the first and second optic fibers are twisted about each other with a central portion in which said first and second optic fibers are fused substantially parallel to each other. The resulting coupler is such that an input light signal is split into output light signals in a predetermined power ratio on the two optic fibers with the coupled power ratio relatively insensitive for a predetermined range of signal wavelengths.Type: GrantFiled: October 30, 1997Date of Patent: November 14, 2000Assignee: E-Tek Dynamics, Inc.Inventors: Jing-Jong Pan, Donna Yu
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Patent number: 6130984Abstract: A variable optical attenuator controllably filters an optical signal after the signal has been expanded and collimated. The optical signals are optionally expanded and refocused by a single GRIN lens, the signal passing through a variable filter between the GRIN lens and a reflector, and again between the reflector and the GRIN lens. Both the input and output fibers can be held within a single sleeve in alignment with the GRIN lens. Alternatively, separate input and output GRIN lenses may be used. The amount of attenuation can be indicated by a potentiometer.Type: GrantFiled: March 4, 1998Date of Patent: October 10, 2000Assignee: E-Tek Dynamics, Inc.Inventors: Ronggui Shen, Jingyu Xu, Jing-Jong Pan
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Patent number: 6097869Abstract: A multiple port reflection based circulator using a thermally expanded multiple core fiber. The circulator includes optical components to separate, rotate, and combine orthogonally polarized components of light in order to propagate light in one direction among consecutive cores of the fiber. The first and last cores of the fiber also being consecutive cores. The thermally expanded multiple core fiber enabling coupling to the circulator without the use of lenses.Type: GrantFiled: June 30, 1999Date of Patent: August 1, 2000Assignee: E-Tek Dynamics, Inc.Inventors: Kok Wai Chang, Yong Huang
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Patent number: 6078716Abstract: An optical fiber having a thermally expanded multiple core section. One such multiple core section may be fabricated by fusing together non-etched multiple fiber claddings resulting in the multiple cores having expanded mode fields that are positioned in close proximity to each other in a common cladding, without signal coupling between the cores. The close proximity of the cores having expanded mode fields may allow for tighter alignment of light waves propagated from one core to other cores.Type: GrantFiled: March 23, 1999Date of Patent: June 20, 2000Assignee: E-TEK Dynamics, Inc.Inventors: Yong Huang, Kok Wai Chang
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Patent number: 6075596Abstract: Improved optical devices, systems, and methods for selectively directing optical signals generally based on a Mach-Zehnder interferometer. Through accurate control of the phase relationship, the Mach-Zehnder interferometer allows optical signals to either be cumulatively combined so as to enhance the transmitted signal strength, or destructively combined so as to effectively prevent transmission from an optical signal port. This phase relationship can be controlled using a nonreciprocal device having a pair of retarder plates disposed along one of the two legs of the Mach-Zehnder interferometer so as to provide an optical isolator or circulator.Type: GrantFiled: May 19, 1998Date of Patent: June 13, 2000Assignee: E-Tek Dynamics, Inc.Inventors: Jing-Jong Pan, Feng Que Zhou
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Patent number: 6058131Abstract: A laser source with an extremely stable output is provided. A laser diode has an output intensity centered at a peak wavelength which is responsive to a control signal. First and second fiber Bragg gratings are coupled to the laser diode. The first fiber Bragg grating having a reflectivity centered about a first wavelength and the second fiber Bragg grating having a reflectivity centered about a second wavelength different from the first wavelength. Each of the first and second fiber Bragg gratings generates a feedback signal responsive to the reflectivity of the fiber Bragg grating and the output intensity of the laser diode. A controller connected to the laser diode generates the control signal responsive to the feedback signals from the first and second fiber Bragg gratings so that the peak wavelength of the laser diode is maintained at a fixed wavelength between the first and second wavelengths.Type: GrantFiled: November 17, 1997Date of Patent: May 2, 2000Assignee: E-Tek Dynamics, Inc.Inventor: Jing-Jong Pan
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Patent number: 6049645Abstract: The present invention provides fiber optic couplers for use with at least three optic fibers. The optic fibers arranged in a linear array, that is, the optic fibers are coupled side by side. The fibers along either end of the linear-array are coupled only to a single fiber, while the remaining fibers are generally coupled between only two adjacent fibers. Generally, at least one of the fibers has a propagation constant different that the other fibers. Such variations in the propagation constant are used to vary the coupling coefficients among the fibers of the linear-array, thereby providing a repeatable mechanism, to vary coupled power ratios among the fibers of the coupler. Theoretical calculations and empirical experience have shown that varying the propagation constant of fibers among a linear-array, generally by pre-pulling the fibers by varying amounts, allows repeatable manufacturing of 1.times.3, 1.times.4, 4.thrfore.3, 1.times.N and even N.times.N fiber couplers having even coupled power ratios.Type: GrantFiled: December 8, 1997Date of Patent: April 11, 2000Assignee: E-Tek Dynamics, Inc.Inventors: Jing-Jong Pan, Ming Shih, Weiti Wu, Yu-Li Ko, Donna S. Yu