Patents by Inventor Mihail M. Sigalas
Mihail M. Sigalas 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).
-
Patent number: 7697584Abstract: A light emitting device includes a structure with a light emitting region disposed between an n-type region and a p-type region. A plurality of holes in the structure, which form a photonic crystal, are formed in a first region of the structure corresponding to a first portion of the light emitting region. A second region of the structure corresponding to a second portion of the light emitting region is free of holes. The device is configured such that when forward biased, current is injected in the second region and the first region is substantially free of current.Type: GrantFiled: October 2, 2006Date of Patent: April 13, 2010Assignee: Philips Lumileds Lighting Company, LLCInventors: Jonathan J. Wierer, Jr., Mihail M. Sigalas
-
Patent number: 7642108Abstract: A photonic crystal light emitting diode (“PXLED”) is provided. The PXLED includes a periodic structure, such as a lattice of holes, formed in the semiconductor layers of an LED. The parameters of the periodic structure are such that the energy of the photons, emitted by the PXLED, lies close to a band edge of the band structure of the periodic structure. Metal electrode layers have a strong influence on the efficiency of the PXLEDs. Also, PXLEDs formed from GaN have a low surface recombination velocity and hence a high efficiency. The PXLEDs are formed with novel fabrication techniques, such as the epitaxial lateral overgrowth technique over a patterned masking layer, yielding semiconductor layers with low defect density. Inverting the PXLED to expose the pattern of the masking layer or using the Talbot effect to create an aligned second patterned masking layer allows the formation of PXLEDs with low defect density.Type: GrantFiled: October 8, 2007Date of Patent: January 5, 2010Assignee: Philips Lumileds Lighting Company, LLCInventors: Michael R. Krames, Mihail M. Sigalas, Jonathan J. Wierer, Jr.
-
Patent number: 7489846Abstract: Photonic crystal sensors may be created from two and three dimensional photonic crystals by introducing defects. The localization of the optical field in the defect region affords the ability to sense small volumes of analyte.Type: GrantFiled: March 11, 2004Date of Patent: February 10, 2009Assignee: Agilent Technologies, Inc.Inventors: Annette Grot, Kai-Cheung Chow, Laura Wills Mirkarimi, Mihail M. Sigalas
-
Patent number: 7442964Abstract: A semiconductor light emitting device includes a photonic crystal structure that is a lattice of holes in the semiconductor layers. The photonic crystal structure includes multiple lattices. In some embodiments, the device includes a first lattice formed on a first region of the semiconductor layers and a second lattice formed on a second region of the semiconductor layers. The parameters of the first lattice may be selected to maximize the total radiated power from the device. The parameters of the second lattice may be selected to maximize the light extraction into a 30° cone on a surface of the stack.Type: GrantFiled: August 4, 2004Date of Patent: October 28, 2008Assignees: Philips Lumileds Lighting Company, LLC, Agilent Technologies, Inc.Inventors: Jonathan J. Wierer, Jr., Mihail M. Sigalas
-
Publication number: 20080080581Abstract: A light emitting device includes a structure with a light emitting region disposed between an n-type region and a p-type region. A plurality of holes in the structure, which form a photonic crystal, are formed in a first region of the structure corresponding to a first portion of the light emitting region. A second region of the structure corresponding to a second portion of the light emitting region is free of holes. The device is configured such that when forward biased, current is injected in the second region and the first region is substantially free of current.Type: ApplicationFiled: October 2, 2006Publication date: April 3, 2008Applicant: PHILIPS LUMILEDS LIGHTING COMPANY, LLCInventors: Jonathan J. Wierer, Mihail M. Sigalas
-
Patent number: 7294862Abstract: A photonic crystal structure is formed in an n-type layer of a III-nitride light emitting device. In some embodiments, the photonic crystal n-type layer is formed on a tunnel junction. The device includes a first layer of first conductivity type, a first layer of second conductivity type, and an active region separating the first layer of first conductivity type from the first layer of second conductivity type. The tunnel junction includes a second layer of first conductivity type and a second layer of second conductivity type and separates the first layer of first conductivity type from a third layer of first conductivity type. A photonic crystal structure is formed in the third layer of first conductivity type.Type: GrantFiled: March 9, 2006Date of Patent: November 13, 2007Assignees: Philips Lumileds Lighting Company, LLC, Avago Technologies General IP Pte. Ltd.Inventors: Jonathan J. Wierer, Jr., Michael R. Krames, Mihail M. Sigalas
-
Patent number: 7279718Abstract: A photonic crystal light emitting diode (“PXLED”) is provided. The PXLED includes a periodic structure, such as a lattice of holes, formed in the semiconductor layers of an LED. The parameters of the periodic structure are such that the energy of the photons, emitted by the PXLED, lies close to a band edge of the band structure of the periodic structure. Metal electrode layers have a strong influence on the efficiency of the PXLEDs. Also, PXLEDs formed from GaN have a low surface recombination velocity and hence a high efficiency. The PXLEDs are formed with novel fabrication techniques, such as the epitaxial lateral overgrowth technique over a patterned masking layer, yielding semiconductor layers with low defect density. Inverting the PXLED to expose the pattern of the masking layer or using the Talbot effect to create an aligned second patterned masking layer allows the formation of PXLEDs with low defect density.Type: GrantFiled: January 28, 2002Date of Patent: October 9, 2007Assignees: Philips Lumileds Lighting Company, LLC, Avago Technologies General IP Pte. Ltd.Inventors: Michael R. Krames, Mihail M. Sigalas, Jonathan J. Wierer, Jr.
-
Patent number: 7012279Abstract: A photonic crystal structure is formed in an n-type layer of a III-nitride light emitting device. In some embodiments, the photonic crystal n-type layer is formed on a tunnel junction. The device includes a first layer of first conductivity type, a first layer of second conductivity type, and an active region separating the first layer of first conductivity type from the first layer of second conductivity type. The tunnel junction includes a second layer of first conductivity type and a second layer of second conductivity type and separates the first layer of first conductivity type from a third layer of first conductivity type. A photonic crystal structure is formed in the third layer of first conductivity type.Type: GrantFiled: October 21, 2003Date of Patent: March 14, 2006Assignees: Lumileds Lighting U.S., LLC, Agilent Technologies, Inc.Inventors: Jonathan J. Wierer Jr., Michael R. Krames, Mihail M. Sigalas
-
Patent number: 6853791Abstract: A two-dimensional photonic crystal slab apparatus having a waveguiding capability is provided. Noncircular holes are introduced to replace the circular holes in the two-dimensional lattice of the photonic crystal to provide waveguiding capability. Waveguide bends and splitter using noncircular holes with high transmittances are described for symmetry planes of the two dimensional lattice structure.Type: GrantFiled: October 31, 2002Date of Patent: February 8, 2005Assignee: Agilent Technologies, Inc.Inventor: Mihail M. Sigalas
-
Patent number: 6775430Abstract: A photonic crystal interferometric switch has a photonic crystal; a waveguide in the photonic crystal, the waveguide having at least one input portion, at least two output portions and an interference channel connecting the at least two output portions, the waveguide capable of transmitting light within a bandgap of said photonic crystal; and a resonant member connected to at least one of the at least two output portions to control a property of light in the at least one output portion, to control the interference of light in the waveguide. A 1×2 optical switch may be constructed by tuning the parameters of the resonant member, either optically or electronically, resulting in a switching of a light signal from one output portion to another output portion. Furthermore, by isolating one output portion of the interferometer, the apparatus may be utilized as an optical modulator.Type: GrantFiled: September 4, 2001Date of Patent: August 10, 2004Assignee: Agilent Technologies, Inc.Inventors: Curt A. Flory, Mihail M. Sigalas
-
Publication number: 20040146242Abstract: An add drop filter utilizing a three dimensional photonic crystal structure for WDM applications is disclosed.Type: ApplicationFiled: January 29, 2003Publication date: July 29, 2004Inventors: Mihail M. Sigalas, Jeremy A. Theil
-
Patent number: 6760514Abstract: A photonic crystal drop filter apparatus and a method for tuning a photonic crystal drop filter. The photonic crystal drop filter has a photonic crystal having first waveguide for transmitting light having a frequency within a bandgap of the photonic crystal, and a second waveguide. The second waveguide is connected to the first waveguide by a resonant cavity for extracting at least one wavelength of the light transmitted by the first waveguide and redirecting the extracted light to the second waveguide. A tuning device is included in the apparatus to tune the wavelength of the extracted light over a full range of wavelengths. The apparatus is particularly suitable as an extraction device for optical communications systems such as a WDM communications system wherein it is necessary to extract one or more carrier signals from a plurality of carrier signals.Type: GrantFiled: February 27, 2002Date of Patent: July 6, 2004Assignee: Agilent Technologies, Inc.Inventors: Carol J. Wilson, Mihail M. Sigalas, Curt Alan Flory
-
Publication number: 20040126055Abstract: A photonic crystal interferometric switch has a photonic crystal; a waveguide in the photonic crystal, the waveguide having at least one input portion, at least two output portions and an interference channel connecting the at least two output portions, the waveguide capable of transmitting light within a bandgap of said photonic crystal; and a resonant member connected to at least one of the at least two output portions to control a property of light in the at least one output portion, to control the interference of light in the waveguide. A 1×2 optical switch may be constructed by tuning the parameters of the resonant member, either optically or electronically, resulting in a switching of a light signal from one output portion to another output portion. Furthermore, by isolating one output portion of the interferometer, the apparatus may be utilized as an optical modulator.Type: ApplicationFiled: September 4, 2001Publication date: July 1, 2004Inventors: Curt A. Flory, Mihail M. Sigalas
-
Patent number: 6747773Abstract: Using a micro-electromechanical actuator, tuning stubs may be actuated for tuning cavities in photonic crystal lattice structures. An actuated tuning stub can be used to tune cavities in both two and three dimensional photonic crystal lattice structures.Type: GrantFiled: October 31, 2002Date of Patent: June 8, 2004Assignee: Agilent Technologies, Inc.Inventors: Jeremy A. Theil, Mihail M. Sigalas, Storrs T. Hoen
-
Publication number: 20040085608Abstract: Using a micro-electromechanical actuator, tuning stubs may be actuated for tuning cavities in photonic crystal lattice structures.Type: ApplicationFiled: October 31, 2002Publication date: May 6, 2004Inventors: Jeremy A. Theil, Mihail M. Sigalas, Storrs T. Hoen
-
Patent number: 6728457Abstract: A two-dimensional photonic crystal slab apparatus having a waveguiding capability is provided. Noncircular holes are introduced to replace the circular holes in the two-dimensional lattice of the photonic crystal to provide waveguiding capability. High guiding efficiency is achieved over a wide frequency region within the photonic bandgap.Type: GrantFiled: July 10, 2002Date of Patent: April 27, 2004Assignee: Agilent Technologies, Inc.Inventors: Mihail M. Sigalas, Kai Cheung Chow
-
Patent number: 6687447Abstract: A photonic crystal waveguide apparatus has a photonic crystal having a waveguide which is capable of transmitting light having a frequency within a bandgap of the photonic crystal, and a resonant stub connected to the waveguide to control light in the waveguide. The resonant stub has a resonator region and a connecting channel which connects the resonator region to the waveguide. The resonant stub controls light transmission characteristics of the waveguide by creating a transmission zero in the transmission band of the waveguide. A tuner for tuning the resonant stub may also be provided to control the transmission zero to provide an active optical apparatus such as an on/off switch or a modulator.Type: GrantFiled: April 30, 2001Date of Patent: February 3, 2004Assignee: Agilent Technologies, Inc.Inventors: Curt A. Flory, Mihail M. Sigalas
-
Publication number: 20040008945Abstract: A two-dimensional photonic crystal slab apparatus having a waveguiding capability is provided. Noncircular holes are introduced to replace the circular holes in the two-dimensional lattice of the photonic crystal to provide waveguiding capability. Waveguide bends and splitter using noncircular holes with high transmittances are described for symmetry planes of the two dimensional lattice structure.Type: ApplicationFiled: October 31, 2002Publication date: January 15, 2004Inventor: Mihail M. Sigalas
-
Publication number: 20040008962Abstract: A two-dimensional photonic crystal slab apparatus having a waveguiding capability is provided. Noncircular holes are introduced to replace the circular holes in the two-dimensional lattice of the photonic crystal to provide waveguiding capability. High guiding efficiency is achieved over a wide frequency region within the photonic bandgap.Type: ApplicationFiled: July 10, 2002Publication date: January 15, 2004Inventors: Mihail M. Sigalas, Kai Cheung Chow
-
Publication number: 20030161577Abstract: A photonic crystal drop filter apparatus and a method for tuning a photonic crystal drop filter. The photonic crystal drop filter has a photonic crystal having first waveguide for transmitting light having a frequency within a bandgap of the photonic crystal, and a second waveguide. The second waveguide is connected to the first waveguide by a resonant cavity for extracting at least one wavelength of the light transmitted by the first waveguide and redirecting the extracted light to the second waveguide. A tuning device is included in the apparatus to tune the wavelength of the extracted light over a full range of wavelengths. The apparatus is particularly suitable as an extraction device for optical communications systems such as a WDM communications system wherein it is necessary to extract one or more carrier signals from a plurality of carrier signals.Type: ApplicationFiled: February 27, 2002Publication date: August 28, 2003Inventors: Carol J. Wilson, Mihail M. Sigalas, Curt Alan Flory