Patents by Inventor Ying L. Luo
Ying L. Luo 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: 10119857Abstract: An integrated optical device includes a photo-detector (such as germanium) optically coupled to an optical waveguide. This photo-detector is deposited on the optical waveguide, and an optical signal propagating in the optical waveguide may be evanescently coupled to the photo-detector. In order to increase the absorption length of the photo-detector, a mirror (such as a distributed Bragg reflection grating) is included in the optical waveguide near the end of the photo-detector. This mirror reflects the optical signal back toward the photo-detector, thereby increasing the absorption of the optical signal by the photo-detector. In addition, absorption may be reduced by using electrical contacts that are electrically coupled to the photo-detector at locations where the optical mode of the optical signal is largely in the underlying optical waveguide, and by using a fingered metal layer to couple to the electrical contacts.Type: GrantFiled: August 17, 2012Date of Patent: November 6, 2018Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Guoliang Li, Xuezhe Zheng, Ying L. Luo, Ashok V. Krishnamoorthy
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Patent number: 9638858Abstract: A hybrid optical source that provides an optical signal having a wavelength (or a narrow band of wavelengths) is described. This hybrid optical source includes an optical amplifier (such as a III-V semiconductor optical amplifier) that is butt-coupled or vertically coupled to a silicon-on-insulator (SOI) platform, and which outputs an optical signal. The SOI platform includes an optical waveguide that conveys the optical signal. A temperature-compensation element included in the optical waveguide compensates for temperature dependence of the indexes of refraction of the optical amplifier and the optical waveguide. In addition, a reflector, adjacent to the optical waveguide after the temperature-compensation element, reflects a portion of the optical signal and transmits another portion of the optical signal that has the wavelength.Type: GrantFiled: August 4, 2014Date of Patent: May 2, 2017Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Ying L. Luo, Xuezhe Zheng, Ashok V. Krishnamoorthy
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Publication number: 20170038609Abstract: An optical modulator is described. This optical modulator may be implemented using silicon-on-insulator (SOI) technology. In particular, a semiconductor layer in an SOI platform may include a photonic crystal having a group velocity of light that is less than that of the semiconductor layer. Moreover, an optical modulator (such as a Mach-Zehnder interferometer) may be implemented in the photonic crystal with a vertical junction in the semiconductor layer. During operation of the optical modulator, an input optical signal may be split into two different optical signals that feed two optical waveguides, and then subsequently combined into an output optical signal. Furthermore, during operation, time-varying bias voltages may be applied across the vertical junction in the optical modulator using contacts defined along a lateral direction of the optical modulator.Type: ApplicationFiled: July 8, 2015Publication date: February 9, 2017Applicant: ORACLE INTERNATIONAL CORPORATIONInventors: Ying L. Luo, Shiyun Lin, Xuezhe Zheng, Ashok V. Krishnamoorthy
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Patent number: 9535308Abstract: A photonic integrated circuit (PIC) is described. This PIC includes a semiconductor-barrier layer-semiconductor diode in an optical waveguide that conveys an optical signal, where the barrier layer is an oxide or a high-k material. Moreover, semiconductor layers in the semiconductor-barrier layer-semiconductor diode may include geometric features (such as a periodic pattern of holes or trenches) that create a lattice-shifted photonic crystal optical waveguide having a group velocity of light that is lower than the group velocity of light in the first semiconductor layer and the second semiconductor layer without the geometric features. The optical waveguide is included in an optical modulator, such as a Mach-Zehnder interferometer (MZI).Type: GrantFiled: September 25, 2013Date of Patent: January 3, 2017Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Guoliang Li, Ashok V. Krishnamoorthy, Xuezhe Zheng, Ying L. Luo, John E. Cunningham
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Patent number: 9519163Abstract: A photonic integrated circuit (PIC) is described. This PIC includes a grating coupler for surface-normal coupling that has an alternating pattern of grating teeth and grating trenches, where the grating trenches are filled with an electro-optical material. By applying an electric potential to the grating teeth, the index of refraction of the electro-optical material can be modified.Type: GrantFiled: September 24, 2013Date of Patent: December 13, 2016Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Xuezhe Zheng, Jin Yao, Guoliang Li, Ying L. Luo, John E. Cunningham, Ashok V. Krishnamoorthy
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Publication number: 20160266320Abstract: An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.Type: ApplicationFiled: May 24, 2016Publication date: September 15, 2016Applicant: Oracle International CorporationInventors: Guoliang Li, Xuezhe Zheng, Ying L. Luo, Ashok V. Krishnamoorthy
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Patent number: 9429812Abstract: An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.Type: GrantFiled: October 5, 2015Date of Patent: August 30, 2016Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Guoliang Li, Xuezhe Zheng, Ying L. Luo, Ashok V. Krishnamoorthy
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Publication number: 20160204578Abstract: An optical source is described. This optical source includes a semiconductor optical amplifier, with a semiconductor other than silicon, which provides a gain medium. In addition, a photonic chip, optically coupled to the semiconductor optical amplifier, includes: an optical waveguide that conveys the optical signal; and a pair of ring-resonator modulators that modulate the optical signal. Furthermore, the pair of ring-resonator modulators is included within an optical cavity in the optical source. For example, the optical cavity may be defined by a reflective coating on one edge of the semiconductor optical amplifier and a reflector on one end of the optical waveguide. Alternatively, the optical cavity may be defined by reflectors on ends of the optical waveguide.Type: ApplicationFiled: October 24, 2013Publication date: July 14, 2016Applicant: Oracle International CorporationInventors: Guoliang Li, Ashok V. Krishnamoorthy, Xuezhe Zheng, Ying L. Luo
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Publication number: 20160170141Abstract: A hybrid optical source that provides an optical signal having a wavelength (or a narrow band of wavelengths) is described. This hybrid optical source includes an optical amplifier (such as a III-V semiconductor optical amplifier) that is butt-coupled or vertically coupled to a silicon-on-insulator (SOI) platform, and which outputs an optical signal. The SOI platform includes an optical waveguide that conveys the optical signal. A temperature-compensation element included in the optical waveguide compensates for temperature dependence of the indexes of refraction of the optical amplifier and the optical waveguide. In addition, a reflector, adjacent to the optical waveguide after the temperature-compensation element, reflects a portion of the optical signal and transmits another portion of the optical signal that has the wavelength.Type: ApplicationFiled: August 4, 2014Publication date: June 16, 2016Inventors: Ying L. Luo, Xuezhe Zheng, Ashok V. Krishnamoorthy
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Publication number: 20160170158Abstract: A technique for fabricating a hybrid optical source is described. During this fabrication technique, a III-V compound-semiconductor active gain medium is integrated with a silicon-on-insulator (SOI) chip (or wafer) using edge coupling to form a co-planar hybrid optical source. Using a backside etch-assisted cleaving technique, and a temporary transparent substrate with alignment markers, a III-V compound-semiconductor chip with proper edge polish and coating can be integrated with a processed SOI chip (or wafer) with accurate alignment. This fabrication technique may significantly reduce the alignment complexity when fabricating the hybrid optical source, and may enable wafer-scale integration.Type: ApplicationFiled: October 22, 2013Publication date: June 16, 2016Applicant: Oracle International CorporationInventors: Xuezhe Zheng, Ivan Shubin, Ying L. Luo, Guoliang Li, Ashok V. Krishnamoorthy
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Patent number: 9369201Abstract: An optical-source monitor images and diffracts received optical signals using an optical device that has a reflective geometry. For example, the optical device may include a diffraction grating on a curved surface, such as an echelle grating. By imaging and diffracting the optical signals, the optical device may couple to the optical signals on different diffraction orders of the optical device (which have different carrier wavelengths) from input optical waveguides to corresponding output optical waveguides. Then, output power monitors may measure the output power levels of the optical signals, and control logic may provide wavelength control signals to optical sources that provide the optical signals based on measured output power levels.Type: GrantFiled: April 23, 2012Date of Patent: June 14, 2016Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Ying L. Luo, Xuezhe Zheng, Ashok V. Krishnamoorthy, Guoliang Li
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Publication number: 20160116821Abstract: An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.Type: ApplicationFiled: October 5, 2015Publication date: April 28, 2016Applicant: ORACLE INTERNATIONAL CORPORATIONInventors: Guoliang Li, Xuezhe Zheng, Ying L. Luo, Ashok V. Krishnamoorthy
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Patent number: 9310562Abstract: In an optical device, a ring resonator, having a resonance wavelength, optically couples an optical signal that includes a wavelength from an input optical waveguide to an output optical waveguide. A monitoring mechanism in the optical device, which is optically coupled to the output optical waveguide, monitors an output optical signal on the output optical waveguide. For example, the monitoring mechanism may dither a temperature of the ring resonator at a frequency using a heater, and the output optical signal may be monitored by determining amplitude and phase information of the output optical signal at the frequency and twice the frequency. Moreover, control logic in the optical device adjusts the resonance wavelength based on the monitored output optical signal, where the adjustment is made without monitoring an input optical signal on the input optical waveguide.Type: GrantFiled: March 11, 2014Date of Patent: April 12, 2016Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Xuezhe Zheng, Guoliang Li, Ying L. Luo, Ashok V. Krishnamoorthy
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Patent number: 9285539Abstract: Using silicon photonic components that support a single polarization, the output of an optical receiver is independent of the polarization of an optical signal. In particular, using a polarization-diversity technique, the two orthogonal polarizations in a single-mode optical fiber are split in two and processed independently. For example, the two optical signals are provided by a polarizing splitting grating coupler. Subsequently, a wavelength channel in the two optical signals is selected using a wavelength-selective filter (for example, using a ring resonator or an echelle grating) and combined at an optical detector (such as a photo-detector) to achieve polarization-independent operation.Type: GrantFiled: August 17, 2012Date of Patent: March 15, 2016Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Xuezhe Zheng, Ying L. Luo, Ashok V. Krishnamoorthy, Guoliang Li
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Patent number: 9176291Abstract: A photonic integrated circuit (PIC) that includes an optical source that provides an optical signal having a wavelength is described. This optical source includes a reflecting layer, a bottom cladding layer, an active layer (such as a III-V semiconductor) having a bandgap wavelength that exceeds that of silicon, and a top cladding layer. Moreover, an optical coupler (such as a grating coupler) that couples the optical signal out of a plane of the active layer is included in a region of the active layer. In this region, the top cladding layer is absent. Furthermore, in an adjacent region, the top cladding layer includes an inverse taper so that the top cladding layer is tapered down from a width distal from the region. In conjunction with the optical coupler, the inverse taper may facilitate low-loss optical coupling of the optical signal between the PIC and another PIC.Type: GrantFiled: August 17, 2012Date of Patent: November 3, 2015Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Guoliang Li, Ying L. Luo, Xuezhe Zheng, John E. Cunningham, Ashok V. Krishnamoorthy
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Patent number: 9176280Abstract: An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.Type: GrantFiled: October 21, 2013Date of Patent: November 3, 2015Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Guoliang Li, Xuezhe Zheng, Ying L. Luo, Ashok V. Krishnamoorthy
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Publication number: 20150277053Abstract: In an optical device, a ring resonator, having a resonance wavelength, optically couples an optical signal that includes a wavelength from an input optical waveguide to an output optical waveguide. A monitoring mechanism in the optical device, which is optically coupled to the output optical waveguide, monitors an output optical signal on the output optical waveguide. For example, the monitoring mechanism may dither a temperature of the ring resonator at a frequency using a heater, and the output optical signal may be monitored by determining amplitude and phase information of the output optical signal at the frequency and twice the frequency. Moreover, control logic in the optical device adjusts the resonance wavelength based on the monitored output optical signal, where the adjustment is made without monitoring an input optical signal on the input optical waveguide.Type: ApplicationFiled: March 11, 2014Publication date: October 1, 2015Applicant: Oracle International CorporationInventors: Xuezhe Zheng, Guoliang Li, Ying L. Luo, Ashok V. Krishnamoorthy
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Publication number: 20150260913Abstract: A photonic integrated circuit (PIC) that includes an optical source that provides an optical signal having a wavelength is described. This optical source includes a reflecting layer, a bottom cladding layer, an active layer (such as a III-V semiconductor) having a bandgap wavelength that exceeds that of silicon, and a top cladding layer. Moreover, an optical coupler (such as a grating coupler) that couples the optical signal out of a plane of the active layer is included in a region of the active layer. In this region, the top cladding layer is absent. Furthermore, in an adjacent region, the top cladding layer includes an inverse taper so that the top cladding layer is tapered down from a width distal from the region. In conjunction with the optical coupler, the inverse taper may facilitate low-loss optical coupling of the optical signal between the PIC and another PIC.Type: ApplicationFiled: August 17, 2012Publication date: September 17, 2015Applicant: ORACLE INTERNATIONAL CORPORATIONInventors: Guoliang Li, Ying L. Luo, Xuezhe Zheng, John E. Cunningham, Ashok V. Krishnamoorthy
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Publication number: 20150260914Abstract: Using silicon photonic components that support a single polarization, the output of an optical receiver is independent of the polarization of an optical signal. In particular, using a polarization-diversity technique, the two orthogonal polarizations in a single-mode optical fiber are split in two and processed independently. For example, the two optical signals are provided by a polarizing splitting grating coupler. Subsequently, a wavelength channel in the two optical signals is selected using a wavelength-selective filter (for example, using a ring resonator or an echelle grating) and combined at an optical detector (such as a photo-detector) to achieve polarization-independent operation.Type: ApplicationFiled: August 17, 2012Publication date: September 17, 2015Applicant: ORACLE INTERNATIONAL CORPORATIONInventors: Xuezhe Zheng, Ying L. Luo, Ashok V. Krishnamoorthy, Guoliang Li
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Patent number: 9052447Abstract: An optical de-MUX includes a sub-wavelength grating that magnifies an input optical signal. In particular, along a direction perpendicular to a propagation direction of the optical signal, the sub-wavelength grating has a spatially varying effective index of refraction that is larger at a center of the sub-wavelength grating than at an edge of the sub-wavelength grating. Moreover, the optical de-MUX includes an optical device that images and diffracts the optical signal using a reflective geometry, and which provides different diffraction orders to output ports. For example, the optical device may include an echelle grating.Type: GrantFiled: November 30, 2011Date of Patent: June 9, 2015Assignee: ORACLE INTERNATIONAL CORPORATIONInventors: Ying L. Luo, Ashok V. Krishnamoorthy, Xuezhe Zheng, Guoliang Li