Oracle International Corporation

Finisar Corporation

Avago Technologies International Sales Pte. Limited

Ii-Vi Delaware, Inc.

Rockley Photonics Limited

Ying Luo

Ashok V Krishnamoorthy

Xuezhe Zheng

Guoliang Li

Shiyun Lin

Jin Yao

John E Cunningham

Jin-Hyoung Lee

Daniel Mahgerefteh

Jock T Bovington

Ivan Shubin

Kannan Raj

Daniel Y Lee

Vivek Raghunathan

Near Margalit

Brett Sawyer

John Drake

Michael Lee

Amit Khanna

Nourhan Eid

Naser Dalvand

A method for improving wafer-level optical characteristic uniformity. The method includes forming a first layer of dielectric overlying the first wafer and a second layer of dielectric overlying the second wafer. The method also includes measuring a refractive index distribution of the second layer and measuring a first thickness distribution of the first layer. The method also includes determining a second thickness distribution for the first layer based on the refractive index distribution and the first thickness distribution. The method further includes removing material nonuniformly and selectively from the first layer based on the second thickness distribution, resulting in a third layer in the second thickness distribution characterized by a spectral response with a characteristic wavelength uniformity better than +/−2.5 nm across the first wafer.

Method for improving optical characteristic uniformity of thin film device

A silicon integrated circuit. In some embodiments, the silicon integrated circuit includes a first conductive trace, on a top surface of the silicon integrated circuit, a dielectric layer, on the first conductive trace, and a second conductive trace, on the dielectric layer, connected to the first conductive trace through a first via.

Silicon photonic interposer with two metal redistribution layers

In one example embodiment, an optical circuit for optical modulation of light may include an input waveguide including a first thickness, an optical modulator including a second thickness, and a tapered transition that optically couples the optical modulator and the input waveguide. The second thickness may be smaller than the first thickness. The tapered transition may adiabatically transform the optical mode of the input waveguide to the optical modulator.

Vertical junction based silicon modulator

In one example embodiment, an integrated silicon photonic wavelength division demultiplexer includes an input waveguide, an input port, a plurality of output waveguides, a plurality of output ports, a first auxiliary waveguide, and a plurality of auxiliary waveguides. The input waveguide may be formed in a first layer and having a first effective index n1. The input port may be optically coupled to the input waveguide. The output waveguides may be formed in the first layer and may have the first effective index n1. Each of the output ports may be optically coupled to a corresponding output waveguide. The first auxiliary waveguide may be formed in a second layer below the input waveguide in the first layer. The first auxiliary waveguide may have a second effective index n2 and may have two tapered ends, and n2 may be higher than n1.

Echelle grating multiplexer or demultiplexer

An optical waveguide may include a silicon portion and a silicon nitride portion positioned over the silicon portion. The silicon portion may include a taper that decreases a width of the silicon portion. The optical waveguide may include a transition between a loaded single mode or multimode waveguide to a single mode waveguide. The silicon nitride portion may confine optical signals traveling through the optical waveguide in the silicon portion.

Waveguide routing configurations and methods

An optical transmitter includes a reflective semiconductor optical amplifier (RSOA) coupled to an input end of a first optical waveguide. An end of the first optical waveguide provides a transmitter output for the optical transmitter. Moreover, a section of the first optical waveguide between the input end and the output end is optically coupled to a ring modulator that modulates an optical signal based on an electrical input signal. A passive ring filter (or a 1&#xd7;N silicon-photonic switch and a bank of band reflectors) is connected to provide a mirror that reflects light received from the second optical waveguide back toward the RSOA to form a lasing cavity. Moreover, the ring modulator and the passive ring filter have different sizes, which causes a Vernier effect that provides a large wavelength tuning range for the lasing cavity in response to tuning the ring modulator and the passive ring filter.

Wavelength-tunable III-V/Si hybrid optical transmitter

The disclosed embodiments provide a laser source comprising a silicon waveguide formed in a silicon layer, and a cascaded array of hybrid distributed feedback (DFB) lasers formed by locating sections of III-V gain material over the silicon waveguide. Each DFB laser in the cascaded array comprises a section of III-V gain material located over the silicon waveguide, wherein the section of III-V gain material includes an active region that generates light, and a Bragg grating located between the III-V gain material and the silicon waveguide. This Bragg grating has a resonance frequency within a gain bandwidth of the section of III-V material and is transparent to frequencies that differ from the resonance frequency. Moreover, each DFB laser has a hybrid mode that resides partially in the III-V gain material and partially in silicon.

Dual-use laser source comprising a cascaded array of hybrid distributed feedback lasers

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.

Reflection-enhanced photo-detector

An optical transmitter includes: a set of reflective silicon optical amplifiers (RSOAs), a set of ring modulators, a shared broadband reflector, a set of intermediate waveguides, and a shared waveguide. Each intermediate waveguide channels light from an RSOA in proximity to an associated ring modulator to cause optically coupled light to circulate in the associated ring modulator. The shared waveguide is coupled to the shared broadband reflector, and passes in proximity to the set of ring modulators, so that light circulating in each ring modulator causes optically coupled light to flow in the shared optical waveguide. During operation, each RSOA forms a lasing cavity with the shared broadband reflector, wherein each lasing cavity has a different wavelength, which is determined by a resonance of the associated ring modulator. The different wavelengths are combined in the shared waveguide to produce a combined output.

Self-tuned silicon-photonic WDM transmitter

An integrated circuit that includes a wavelength-filter layer stack (which may include silicon oxynitride) and an optical substrate (such as a silicon-on-insulator platform) is described. During operation, an optical signal received from an optical fiber or an optical waveguide is wavelength filtered into a set of wavelength-filter optical waveguides by an optical multiplexer/demultiplexer (such as an Echelle grating and/or an array waveguide grating) in the wavelength-filter layer stack. Then, wavelength-filtered optical signals are optically coupled to the optical substrate, where they are received using photodetectors. Alternatively, modulators in the optical substrate modulate wavelength-filtered modulated optical signals, which are then optically coupled to the set of wavelength-filter optical waveguides in the wavelength-filter layer stack. Next, the wavelength-filtered modulated optical signals are combined using the optical multiplexer/demultiplexer, and the resulting optical signal is output to the optical fiber or the optical waveguide.

Polarization-insensitive optical transceiver

The disclosed embodiments provide a system that implements an optical interface. The system includes a semiconductor chip with a silicon layer, which includes a silicon waveguide, and an interface layer (which can be comprised of SiON) disposed over the silicon layer, wherein the interface layer includes an interface waveguide. The system also includes an optical coupler that couples an optical signal from the silicon waveguide in the silicon layer to the interface waveguide in the interface layer, wherein the interface waveguide channels the optical signal in a direction parallel to a top surface of the semiconductor chip. The system additionally includes a mirror, which is oriented to reflect the optical signal from the interface waveguide in a surface-normal direction so that the optical signal exits the top surface of the semiconductor chip.

Surface-normal optical coupling interface with thermal-optic coefficient compensation

A dual-ring-modulated laser includes a gain medium having a reflective end coupled to a gain-medium reflector and an output end coupled to a reflector circuit to form a lasing cavity. This reflector circuit comprises: a first ring modulator; a second ring modulator; and a shared waveguide that optically couples the first and second ring modulators. The first and second ring modulators have resonance peaks, which are tuned to have an alignment separation from each other. During operation, the first and second ring modulators are driven in opposing directions based on the same electrical input signal, so the resonance peaks of the first and second ring modulators shift wavelengths in the opposing directions during modulation. The modulation shift for each of the resonance peaks equals the alignment separation, so the resonance peaks interchange positions during modulation to cancel out reflectivity changes in the lasing cavity caused by the modulation.

Dual-ring-modulated laser that uses push-pull modulation

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.

Slow-light silicon optical modulator

An optical transmitter includes: a set of reflective semiconductor optical amplifiers (RSOAs) or other reflective gain media, a set of ring filters, a set of intermediate waveguides, a shared waveguide, a shared loop mirror, and an output waveguide. Each intermediate waveguide channels light from an RSOA in proximity to an associated ring filter to cause optically coupled light to circulate in the associated ring filter. The shared waveguide is coupled to the shared loop mirror, and is located in proximity to the set of ring filters, so that light circulating in each ring filter causes optically coupled light to flow in the shared waveguide. Each RSOA forms a lasing cavity with the shared loop reflector, wherein each lasing cavity has a different wavelength associated with a resonance of its associated ring filter. The output waveguide is optically coupled to the shared loop mirror and includes an electro-optical modulator.

Growing community of inventors

San Diego, CA, United States of America

Ying Luo