Patents by Inventor Tawee Tanbun-Ek
Tawee Tanbun-Ek 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: 7433567Abstract: A multi-quantum well optical waveguide structure comprises a plurality of active regions including quantum wells with different gain peak wavelengths to provide an ultra broadband optical gain spectrum. Two adjacent sets of active regions having a large band gap difference are connected by a tunneling injection layer to provide smooth electron transport. Single transverse-mode operation is obtained by narrowly tapering the width of the multi-quantum well optical waveguide from the center to the two ends. Higher-order modes are suppressed at the output of the tapered waveguide, even though the center waveguide portion supports higher-order modes. In this way, the multi-quantum well optical waveguide can be utilized for ultra broadband optical amplification using a single mode fiber.Type: GrantFiled: April 13, 2005Date of Patent: October 7, 2008Inventors: Fow-Sen Choa, Tawee Tanbun-Ek
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Publication number: 20060233213Abstract: A multi-quantum well optical waveguide structure comprises a plurality of active regions including quantum wells with different gain peak wavelengths to provide an ultra broadband optical gain spectrum. Two adjacent sets of active regions having a large band gap difference are connected by a tunneling injection layer to provide smooth electron transport. Single transverse-mode operation is obtained by narrowly tapering the width of the multi-quantum well optical waveguide from the center to the two ends. Higher-order modes are suppressed at the output of the tapered waveguide, even though the center waveguide portion supports higher-order modes. In this way, the multi- quantum well optical waveguide can be utilized for ultra broadband optical amplification using a single mode fiber.Type: ApplicationFiled: April 13, 2005Publication date: October 19, 2006Inventors: Fow-Sen Choa, Tawee Tanbun-Ek
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Patent number: 7031612Abstract: An optical transponder/transceiver for intermediate range (e.g., 10-50 km) optical communication applications utilizes an electroabsorption modulated laser for the transmitting device. Preferably, the laser operations at a wavelength of approximately 1310 nm and comprises an electroabsorption modulated Fabry-Perot laser.Type: GrantFiled: July 17, 2001Date of Patent: April 18, 2006Assignee: Multiplex, Inc.Inventors: Kang-Yih Liou, Tawee Tanbun-Ek, Won-Tien Tsang, Liang David Tzeng
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Patent number: 6597718Abstract: An electroabsorption modulated laser (EML) is formed to include a Fabry-Perot lasing section, in place of the conventional DFB lasing section. When operated at a wavelength of 1310 nm, the wider spectral bandwidth of the FP device (containing several longitudinal modes) is of no concern, since 1310 nm is the zero dispersion wavelength of most conventional transmission fibers. A selective area growth process is used to simultaneously form the MQW active regions of both the FP and EA sections of the EML device, and an isolation trench may be formed between the sections to reduce the effects of electrical crosstalk.Type: GrantFiled: July 17, 2001Date of Patent: July 22, 2003Assignee: Multiplex, Inc.Inventors: Tawee Tanbun-Ek, Won-Tien Tsang, Liang David Tzeng
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Publication number: 20020060824Abstract: An optical transponder/transceiver for intermediate range (e.g., 10-50 km) optical communication applications utilizes an electroabsorption modulated laser for the transmitting device. Preferably, the laser operations at a wavelength of approximately 1310 nm and comprises an electroabsorption modulated Fabry-Perot laser.Type: ApplicationFiled: July 17, 2001Publication date: May 23, 2002Inventors: Kang-Yih Liou, Tawee Tanbun-Ek, Won-Tien Tsang, Liang David Tzeng
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Publication number: 20020009114Abstract: An electroabsorption modulated laser (EML) is formed to include a Fabry-Perot lasing section, in place of the conventional DFB lasing section. When operated at a wavelength of 1310 nm, the wider spectral bandwidth of the FP device (containing several longitudinal modes) is of no concern, since 1310 nm is the zero dispersion wavelength of most conventional transmission fibers. A selective area growth process is used to simultaneously form the MQW active regions of both the FP and EA sections of the EML device, and an isolation trench may be formed between the sections to reduce the effects of electrical crosstalk.Type: ApplicationFiled: July 17, 2001Publication date: January 24, 2002Inventors: Tawee Tanbun-Ek, Won-Tien Tsang, Liang David Tzeng
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Patent number: 6331908Abstract: A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A tuning voltage applied to the composite reflector induces refractive index changes, thereby allowing the center wavelength to be altered.Type: GrantFiled: November 22, 1999Date of Patent: December 18, 2001Assignee: Lucent Technologies Inc.Inventors: Laura Ellen Adams, Clyde George Bethea, Lars Erik Eskildsen, Gerald Nykolak, Rossevelt People, Tawee Tanbun-Ek
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Patent number: 6166837Abstract: A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A tuning voltage applied to the composite reflector induces refractive index changes, thereby allowing the center wavelength to be altered.Type: GrantFiled: November 22, 1999Date of Patent: December 26, 2000Assignee: Lucent Technologies Inc.Inventors: Laura Ellen Adams, Clyde George Bethea, Lars Erik Eskildsen, Gerald Nykolak, Roosevelt People, Tawee Tanbun-Ek
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Patent number: 6108362Abstract: A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A voltage applied to the composite reflector induces a quantum confined stark effect, thereby allowing the wavelength to be altered. In one embodiment, the current drive to the active region and the shape of the first waveguide (e.g., a raised-sine function) are mutually adapted so that N longitudinal modes have essentially the same threshold gain and so that the DFB region spanned by the first waveguide is segmented into N zones, each zone providing optical feedback at a different wavelength corresponding to a different longitudinal mode.Type: GrantFiled: October 17, 1997Date of Patent: August 22, 2000Assignee: Lucent Technologies Inc.Inventors: Laura Ellen Adams, Clyde George Bethea, Wei-Chiao Fang, Gerald Nykolak, Roosevelt People, Arthur Mike Sergent, Tawee Tanbun-Ek, Won-Tien Tsang
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Patent number: 6081361Abstract: In a WDM fiber-optic network, a unique laser transmitter enables signals to be routed at three hierarchical levels: at one level discrimination among signal paths is based on N WDM wavelength channels, at another level discrimination is based on m AM subcarrier frequency channels, and at a third level discrimination is based on n FM subcarrier frequency channels. Thus, a total of Nmn distinguishable optical channels can be accommodated and a like number of users served. The laser transmitter comprises a broadband, tunable semiconductor laser which includes an intracavity, integrated composite reflector to which a tuning voltage and a FM dither signal are applied, an intracavity gain section to which drive current is applied, and an extracavity, integrated electroabsorption modulator to which an information (e.g., data, voice, video) signal and an AM dither signal are applied.Type: GrantFiled: October 17, 1997Date of Patent: June 27, 2000Assignee: Lucent Technologies Inc.Inventors: Laura Ellen Adams, Clyde George Bethea, Gerald Nykolak, Roosevelt People, Tawee Tanbun-Ek
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Patent number: 5991061Abstract: A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A tuning voltage applied to the composite reflector induces refractive index changes, thereby allowing the center wavelength to be altered. A dither signal applied the composite reflector broadens the spectrum of the laser output, thereby reducing SBS in fiber optic systems.Type: GrantFiled: October 20, 1997Date of Patent: November 23, 1999Assignee: Lucent Technologies Inc.Inventors: Laura Ellen Adams, Clyde George Bethea, Lars Erik Eskildsen, Gerald Nykolak, Roosevelt People, Tawee Tanbun-Ek
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Patent number: 5991323Abstract: A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A tuning voltage applied to the composite reflector induces a quantum confined stark effect, thereby allowing the center wavelength to be altered. A pre-chirp signal applied the composite reflector reduces signal distortion in fiber optic systems.Type: GrantFiled: October 20, 1997Date of Patent: November 23, 1999Assignee: Lucent Technologies Inc.Inventors: Laura Ellen Adams, Clyde George Bethea, Gerald Nykolak, Roosevelt People, Tawee Tanbun-Ek
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Patent number: 5721796Abstract: In accordance with the invention a multiwavelength optical fiber cross connect is provided with an active all-fiber optical router for multiplexing/demultiplexing. The router is comprised of one electronic component--a phase controller--and four fiber components: 1) a fiber directional coupler, 2) a fiber reflective grating filter, 3) a fiber tap, and 4) a fiber phase modulator. The application describes how to make optical routers from these components ranging in complexity from a single wavelength drop router to an N-port, N-wavelength router for add/drop multiplexing. The application also describes how optical wavelength routers can be combined to create optical fiber Cross connect (OXCs), ranging in complexity from 2.times.2 single wavelength OXCs to NXN, M-wavelength OXCs.Type: GrantFiled: June 21, 1996Date of Patent: February 24, 1998Assignee: Lucent Technologies Inc.Inventors: Miriam R. de Barros, Lars Erik Eskildsen, Gerald Nykolak, Ashish Madhukar Vengsarkar, Torben N. Nielsen, Tawee Tanbun-Ek
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Patent number: 5040186Abstract: Disclosed is a graded index separate confinement heterostructure quantum well (GRIN-SCH QW) laser with continuously graded, substantially index matched InGaAsP confinement layer. The inventive device is well adapted for high power output in the wavelength region 1.2-1.68 .mu.m. In particular, it can readily be designed to have an output wavelength that makes it suitable as pump source for Er-doped optical fiber amplifiers. A method of manufacturing a laser according to the invention is also disclosed.Type: GrantFiled: August 7, 1990Date of Patent: August 13, 1991Assignee: AT&T Bell LaboratoriesInventors: Ralph A. Logan, Tawee Tanbun-Ek, Henryk Temkin
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Patent number: 4953170Abstract: Described is a method for forming epitaxial films comprising successive layers of at least ternary and at least quaternary III-V material grown by metalorganic vapor-phase epitaxy. Between the steps of growing successive layers, the growth chamber is first flushed, advantageously in successive steps using a pair of gaseous Group V hybrides, a few monolayers of binary III-V material are then deposited, and then the growth chamber is again flushed. As a result, interfaces are sharper and interfacial defects are reduced. Also described are quantum well lasers made according to the inventive method.Type: GrantFiled: June 15, 1989Date of Patent: August 28, 1990Assignee: AT&T Bell LaboratoriesInventors: Ralph A. Logan, Tawee Tanbun-ek, Henryk Temkin