Patents Assigned to T-Networks, Inc.
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Patent number: 7106774Abstract: An amplified laser comprising a semiconductor laser and semiconductor optical amplifier (SOA) mounted on a substrate such that an optical signal generated by the laser is optically coupled to the SOA. The SOA and laser are electrically coupled in a series configuration or a parallel configuration such that a single DC lead is needed to provide operational power and a single lead is needed to provide ground to both optical components. Additionally, a monolithic distributed feedback semiconductor laser (DFB) and SOA device comprising a substrate, a diffraction grating formed on the substrate, an active layer waveguide extending over the substrate and grating, a semiconductor layer formed over the active layer, and an electrical contact layer including varying resistive elements formed on the semiconductor layer. Either device may be contained in an industry standard 7-PIN electro-absorption modulated laser (EML) package.Type: GrantFiled: August 20, 2003Date of Patent: September 12, 2006Assignee: T-Networks, Inc.Inventor: Aaron Fisher
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Patent number: 7016556Abstract: An optical device includes an optical waveguide through which light propagates and a micro-resonator structure including an optical sensor. The micro-resonator is configured to resonate at a wavelength of light that may be transmitted through the optical waveguide. When light at that wavelength is transmitted through the optical waveguide, it resonates in the resonator and is detected by the optical sensor to produce an electrical signal. The optical resonator may be a micro-cylinder, disc or ring resonator and may be coupled to the waveguide via evanescent coupling or leaky-mode coupling. Multiple resonators may be implemented proximate to the waveguide to allow multiple wavelengths to be detected. When the waveguide is coupled to a tunable laser, signals provided by the optical sensor may be used to tune the wavelength of the laser.Type: GrantFiled: June 15, 2004Date of Patent: March 21, 2006Assignee: T-Networks, Inc.Inventors: John Kai Andersen, Newton C. Frateschi
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Patent number: 6987908Abstract: A grating dispersion compensator (GDC), including: a substrate; a dielectric grating layer; a planar waveguide; and a passivation layer. The dielectric grating layer may be formed on the substrate and includes a variation in refractive index. This variation in refractive index defines a grating period. The grating period may vary along the longitudinal axis of the GDC according to a predetermined function. A selected center wavelength and dispersion curve may be created. The chirp of the grating period may be controlled by current, voltage, temperature, or pressure. The planar waveguide is formed on the dielectric grating layer and includes an input/output (I/O) surface normal to the longitudinal axis of the planar waveguide. The passivation layer is formed on the planar waveguide. Alternatively, a GDC may be formed with the dielectric grating layer on top of the planar waveguide rather then beneath it.Type: GrantFiled: June 11, 2002Date of Patent: January 17, 2006Assignee: T-Networks, Inc.Inventors: Aaron Bond, Ram Jambunathan, Newton C. Frateschi
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Patent number: 6985644Abstract: An optical device includes an optical waveguide through which light propagates and a micro-resonator structure including an optical sensor. The micro-resonator is configured to resonate at a wavelength of light that may be transmitted through the optical waveguide. When light at that wavelength is transmitted through the optical waveguide, it resonates in the resonator and is detected by the optical sensor to produce an electrical signal. The optical resonator may be a micro-cylinder, disc or ring resonator and may be coupled to the waveguide via evanescent coupling or leaky-mode coupling. Multiple resonators may be implemented proximate to the waveguide to allow multiple wavelengths to be detected. When the waveguide is coupled to a tunable laser, signals provided by the optical sensor may be used to tune the wavelength of the laser.Type: GrantFiled: September 16, 2002Date of Patent: January 10, 2006Assignee: T-Networks, Inc.Inventors: John Kai Andersen, Newton C. Frateschi
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Patent number: 6967770Abstract: An active optical device with reduced axial carrier depletion is disclosed. This active optical device includes a substrate layer; a p-doped active layer coupled to the substrate, a semiconductor layer coupled to the active layer, an electrical contact coupled to the substrate layer, and an electrical contact coupled to the semiconductor layer. The p-doped active layer has a central interaction region and a transverse diffusion region. The transverse diffusion region supplies additional carriers to the central interaction region in response to carrier depletion in the central interaction region caused by the interaction of the carriers with a light beam. Also a method of operation and a method of manufacture for the active optical device is disclosed.Type: GrantFiled: July 20, 2004Date of Patent: November 22, 2005Assignee: T-Networks, Inc.Inventor: Newton C. Frateschi
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Patent number: 6891665Abstract: An active optical device with reduced axial carrier depletion is disclosed. This active optical device includes a substrate layer; a p-doped active layer coupled to the substrate, a semiconductor layer coupled to the active layer, an electrical contact coupled to the substrate layer, and an electrical contact coupled to the semiconductor layer. The p-doped active layer has a central interaction region and a transverse diffusion region. The transverse diffusion region supplies additional carriers to the central interaction region in response to carrier depletion in the central interaction region caused by the interaction of the carriers with a light beam. Also a method of operation and a method of manufacture for the active optical device is disclosed.Type: GrantFiled: July 17, 2002Date of Patent: May 10, 2005Assignee: T-Networks, Inc.Inventor: Newton C. Frateschi
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Patent number: 6862376Abstract: A method of manufacturing a monolithic expanded beam mode electroabsorption modulator including a waveguide layer with a two expansion/contraction sections and an electroabsorption section arranged along a longitudinal axis. At least one patterned growth retarding layer is formed on the top surface of a substrate. The waveguide layer is formed on a portion of the top surface of the substrate by selective area growth and has an index of refraction different from the substrate. An electroabsorption portion of the waveguide layer has a thickness which is greater than thicknesses in its other portions. The semiconductor layer is formed on the waveguide layer and includes an index of refraction different from the waveguide. The waveguide and semiconductor layers are defined and etched to form the expansion/contraction and electroabsorption sections of the waveguide layer. Electrical contacts are formed, one electrically coupled to the substrate and another electrically coupled to the semiconductor layer.Type: GrantFiled: July 21, 2004Date of Patent: March 1, 2005Assignee: T-Networks, Inc.Inventors: Aaron Bond, Ram Jambunathan, Won Jin Choi
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Patent number: 6856441Abstract: A method of tuning an electroabsorption modulator (EAM). A reference average power loss factor for light having a reference peak wavelength that is modulated by the EAM is provided. This loss factor is based on operation of the EAM using a reference bias voltage, a reference temperature, and a reference modulation signal which has a predetermined duty cycle. Input light is coupled into the EAM and modulated using a modulation signal which has the same duty cycle as the reference modulation signal. The input power of the input light and the average output power of light emitted from the EAM are measured. These input and average output powers are used to generate an average power loss factor. The average power loss factor is compared to the reference average power loss factor and the bias voltage and/or the temperature of the EAM are adjusted to reduce differences between these loss factors.Type: GrantFiled: August 25, 2003Date of Patent: February 15, 2005Assignee: T-Networks, Inc.Inventors: Liyan Zhang, Newton C. Frateschi, Jiaming Zhang, Aaron Bond
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Patent number: 6844954Abstract: An exemplary monolithic stabilized monolithic transmissive active optical device, such as an electroabsorption modulator (EAM), a variable optical attenuator (VOA), or a semiconductor optical amplifier (SOA), with an output optical tap, is formed from: a substrate; a waveguide layer; a semiconductor layer. The waveguide layer is coupled to the substrate and includes an active medium, which interacts with a predetermined wavelength of light, and is responsive to an electric signal. The electric signal is applied between the substrate and the semiconductor layer. The waveguide layer includes an output optical tap section and an active section adjacent to the output optical tap section. These sections include portions of the active medium. Further embodiments of the present invention incorporate temperature as well as bias control to improve performance of exemplary monolithic transmissive active optical devices.Type: GrantFiled: August 6, 2003Date of Patent: January 18, 2005Assignee: T-Networks, Inc.Inventors: Aaron Bond, John Kai Anderson, Ram Jambunathan
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Patent number: 6844212Abstract: A grating dispersion compensator (GDC), including: a substrate; a dielectric grating layer; a planar waveguide; and a passivation layer; is disclosed. The dielectric grating layer may be formed on the substrate and includes a variation in refractive index. This variation in refractive index defines a grating period. The grating period may vary along the longitudinal axis of the GDC according to a predetermined function. A selected center wavelength and dispersion curve may be created. The chirp of the grating period may be controlled by current, voltage, temperature, or pressure. The planar waveguide is formed on the dielectric grating layer and includes an input/output (I/O) surface normal to the longitudinal axis of the planar waveguide. The passivation layer is formed on the planar waveguide. Alternatively, a GDC may be formed with the dielectric grating layer on top of the planar waveguide rather than beneath it.Type: GrantFiled: May 12, 2004Date of Patent: January 18, 2005Assignee: T-Networks, Inc.Inventors: Aaron Bond, Ram Jambunathan, Newton C. Frateschi
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Patent number: 6835004Abstract: An opto-electronic package is provided for mounting on a module base. The package comprises a generally rectangular package. An optical connector extends from a first side of the package body along an optical axis, generally parallel to the module base. A radio frequency connector extends from a second side of the package body along a RF axis, generally parallel to the module base. A plurality of electronic leads and mounting tabs each extend from at least one of the second side and a third side of the package body. A fourth side of the package body is adjacent the first side and free of connectors, leads, and mounting tabs for mounting the package in a corner of the module formed by first and second module walls. The fourth wall of the package body is positioned adjacent the first module wall and the optical connector extends through the second module wall.Type: GrantFiled: August 26, 2002Date of Patent: December 28, 2004Assignee: T-Networks, Inc.Inventors: Jason T. Iceman, Walter Jeffery Shakespeare, John Kai Andersen
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Patent number: 6836350Abstract: Drive circuitry to provide a DC bias voltage and a high frequency modulation current to an electroabsorption modulator (EAM), including a high frequency modulation current source, a coupling capacitor, and a first DC lead. The drive circuitry may include termination circuitry. One lead of the high frequency modulation current source is electrically coupled to the first semiconductor type contact of the EAM and the other lead of the high frequency modulation current source is electrically coupled to an AC ground. The coupling capacitor includes a first electrode electrically coupled to the second semiconductor type contact of the EAM, a second electrode electrically coupled to the AC ground, and a dielectric layer between the electrodes. The first DC lead is electrically coupled to the EAM-side capacitor electrode and configured to be coupled to a first DC potential.Type: GrantFiled: March 5, 2004Date of Patent: December 28, 2004Assignees: T-Networks, Inc., AMCCInventors: Prashant Singh, Helga Foulk, Scott Redinger, Todd Tanji, Keith Maile, John Stronczer
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Patent number: 6825964Abstract: Drive circuitry to provide a DC bias voltage and a high frequency modulation current to an electroabsorption modulator (EAM), including a high frequency modulation current source, a coupling capacitor, and a first DC lead. The drive circuitry may include termination circuitry. One lead of the high frequency modulation current source is electrically coupled to the first semiconductor type contact of the EAM and the other lead of the high frequency modulation current source is electrically coupled to an AC ground. The coupling capacitor includes a first electrode electrically coupled to the second semiconductor type contact of the EAM, a second electrode electrically coupled to the AC ground, and a dielectric layer between the electrodes. The first DC lead is electrically coupled to the EAM-side capacitor electrode and configured to be coupled to a first DC potential.Type: GrantFiled: October 22, 2002Date of Patent: November 30, 2004Assignees: T-Networks, Inc., AMCCInventors: Prashant Singh, Helga Foulk, Scott Redinger, Todd Tanji, Keith Maile, John Stronczer
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Patent number: 6804421Abstract: A monolithic single pass expanded beam mode active optical device includes: a substrate; a waveguide layer coupled to the top surface of the substrate; a semiconductor layer coupled to the waveguide layer; first and second electrodes for receiving an electric signal coupled to the substrate and the semiconductor layer, respectively. The waveguide layer includes a plurality of sublayers, forming a quantum well structure, which is responsive to the electric signal. The waveguide layer has three sections, two expansion/contraction sections and an active section, which extends between and adjacent to the two expansion/contraction sections. The thickness of at least one of the plurality of sublayers varies within the expansion/contraction portions of the quantum well structure. Possible interactions of the active region with the light include: absorption in the case of an electro-absorptive modulator and optical gain.Type: GrantFiled: January 25, 2002Date of Patent: October 12, 2004Assignee: T-Networks, Inc.Inventors: Aaron Bond, Ram Jambunathan, Won Jin Choi
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Patent number: 6661556Abstract: An exemplary monolithic stabilized monolithic transmissive active optical device, such as an electroabsorption modulator (EAM), a variable optical attenuator (VOA), or a semiconductor optical amplifier (SOA), with an output optical tap, includes: a substrate; a waveguide layer; a semiconductor layer. The waveguide layer is coupled to the substrate and includes an active medium, which interacts with a predetermined wavelength of light, and is responsive to an electric signal. The electric signal is applied between the substrate and the semiconductor layer. The waveguide layer includes an output optical tap section and an active section adjacent to the output optical tap section. These sections include portions of the active medium. Further embodiments of the present invention incorporate temperature as well as bias control to improve performance of exemplary monolithic transmissive active optical devices. Additional embodiments include exemplary methods of manufacture and methods of operation.Type: GrantFiled: August 14, 2002Date of Patent: December 9, 2003Assignee: T-Networks, Inc.Inventors: Aaron Bond, John Kai Andersen, Ram Jambunathan