81 results about "Semiconductor waveguides" patented technology

The invention discloses a method for monolithic integration of active devices within passive semiconductor waveguides and the application of this method for use in InP-based planar wavelength division multiplexing components of optical communication systems. The epitaxial device is grown in a single run and comprises a number of layers, such that the lower part of the structure acts as a single mode passive waveguide while the upper part of the structure contains a planar PIN diode. The PIN structure is present only in the active waveguide portion and absent in all the passive waveguide portions. The active and passive waveguide portions have substantially similar guiding properties with the exception of a mode tail above a top surface of the passive waveguide portion within the active waveguide portion. As a result, an optical signal portion penetrates the I-layer of the PIN structure and interacts with semiconductor material therein for actively affecting an intensity of the optical signal with no substantial changes in guiding properties of the semiconductor waveguide. Embodiments of invention in the form of monolithically integrated waveguide photodetector, electro-absorptive attenuator and semiconductor optical amplifier are disclosed in terms of detailed epitaxial structure, layout and performance characteristics of the device.

A method for realizing a semiconductor waveguide and an ultra-low-loss dielectric waveguide disposed on the same substrate is disclosed. The method includes forming a partial dielectric waveguide structure on the substrate, wherein the dielectric waveguide is annealed to reduce hydrogen incorporation, and wherein the top cladding of the dielectric waveguide is only partially formed by a first dielectric layer. A second substrate comprising a semiconductor layer having a second dielectric layer disposed on its top surface is bonded to the first substrate such that the first and second dielectric layers collectively form the complete top cladding for the dielectric waveguide. The second substrate is then removed and the semiconductor layer is patterned to define the semiconductor waveguide core.

Current may be passed through an n-doped semiconductor region, a recessed metal semiconductor alloy portion, and a p-doped semiconductor region so that the diffusion of majority charge carriers in the doped semiconductor regions transfers heat from or into the semiconductor waveguide through Peltier-Seebeck effect. Further, a temperature control device may be configured to include a metal semiconductor alloy region located in proximity to an optoelectronic device, a first semiconductor region having a p-type doping, and a second semiconductor region having an n-type doping. The temperature of the optoelectronic device may thus be controlled to stabilize the performance of the optoelectronic device.

An optical signal low energy method for coupling electrical signals on-chip between component circuits of for example a CMOS circuit array. The described coupling method employs infrared signals communicated along a nano-scale resonant semiconductor waveguide between for example PIN diode signal transducers. The coupling may employ an electrically pumped laser, an electro absorption modulator and a photodetector all for typically the 1.5 to 2.0 micrometer spectral region with each formed using for example PIN heterodiode semiconductor devices. Each of these three devices includes active semiconductor crystal material situated in a resonator within a strip waveguide. The resonator is defined by two fabricated mirrors having a tapered location one dimensional photonic crystal lattice of oxide hole or slot apertures. Each semiconductor device is for example a heterodiode pumped or controlled by laterally disposed wings enclosing the resonator to form a lateral PIN structure for current injection or high E-field generation. CMOS compatible ten gigabit per second signals of low energy use per transmitted bit are achieved.

The optical phase modulator of the present invention comprises: a main Mach-Zehnder interferometer having first and second main optical waveguide path arms, and whose initial phase difference in the used wavelength is π; a first sub Mach-Zehnder interferometer having first and second sub optical waveguide path arms that are formed in said first main optical waveguide path arm, and whose initial phase difference in the used wavelength is 0; and a second sub Mach-Zehnder interferometer having third and fourth sub optical waveguide path arms that are formed in said second main optical waveguide path arm, and whose initial phase difference in the used wavelength is 0. Of each of the main optical waveguide path arms and first through fourth sub optical waveguide path arms, at least the portions where high-frequency electrodes are formed is constructed using semiconductor waveguide paths, and are capable of reducing the effects of frequency chirping caused by an orthogonal component that occurs due to light absorption in the semiconductor.

An exemplary optical isolator, such as a magnetic-semiconductor composite optical isolator, and method for making the same, is provided that includes a semiconductor waveguide and a magnetic-semiconductor composite layer. The semiconductor waveguide includes a guide layer, a first clad layer and a second clad layer. The guide layer includes one or more layers with a first end, a second end, a top, and a bottom, the guide layer allows a light wave incident the first end of the guide layer to propagate in a positive propagation direction, and allows a light wave incident the second end of the guide layer to propagate in a negative propagation direction. The first clad layer and the second clad layer are provided, respectively, relative to the bottom and the top of the guide layer, and the second clad layer has a thickness to allow an optical field penetration through the second clad layer. The magnetic-semiconductor composite layer is provided in the presence of a magnetic field oriented in a desired direction and is positioned relative the second clad layer and at a thickness and index of refraction to receive the optical field penetration through the second clad layer and to attenuate a light wave that propagates in the negative propagation direction more than the attenuation of a light wave that propagates in the positive propagation direction. The magnetic-semiconductor composite optical isolator may be integrated with a semiconductor laser, such as on the same semiconductor substrate.

An improved optical communication system is provided, the system particularly suited for so-called short-haul applications, e.g., applications involving transmission over distances less than 100 km, such as metro applications. The system uses an external cavity laser made up of a gain medium that comprises an active region, a beam expanding region, and an antireflective layer, an optical waveguide located adjacent the gain medium, and a Bragg grating integral with or coupled to the optical waveguide. The medium and the optical waveguide, due to the beam expanding region, exhibit a coupling efficiency of at least 40%, advantageously at least 50%, even in the absence of coupling optics, and the laser is configured and operated to emit at least two modes.

Integrated semiconductor waveguide gratings, methods of manufacture thereof and methods of apodizing thereof are described. A semiconductor waveguide grating includes a substrate, a cladding layer disposed on the substrate, a guide structure that includes a plurality of discrete transverse sections implanted with ions disposed between adjacent transverse sections substantially free of implanted ions.

An optical integrated circuit 1 according to the present invention includes a planar lightwave circuit 2, and a semiconductor element 3, which are fixed at one contact surface 12. A semiconductor optical amplifier (SOA) 9 is formed on a semiconductor substrate 8. A semiconductor waveguide 10 and a semiconductor waveguide 11 are formed on an input side and an output side of SOA 9, respectively. The semiconductor waveguide 11 has a turnaround portion 11a turned around on the semiconductor substrate 8. Respective ends of the optical waveguides 5 and 6 on a PLC platform 4 and respective ends of semiconductor waveguides 10 and 11 are optically coupled with each other at the contact surface 12.

Methods and devices for providing a multiwavelength laser which may be used for multicasting and other optical communications uses. The present invention provides a quantum dot based multiwavelength laser with a monolithic gain block. The Fabry-Perot gain block has both upper and lower InP cladding layers. The laser system has a middle quantum dot layer with multiple stacked layers of InAs quantum dots embedded in InGaAsP. When provided with a CW injection current, the laser system produces an output spectra with equally spaced multiple emission peaks. With an input optical data signal applied to the laser system, the laser system duplicates the data in the input signal across multiple different wavelengths.

A semiconductor optical integrated device including: a substrate having a first area, a second area and a third area arranged in a waveguiding direction; a laser portion disposed on the third area the laser portion including a laser waveguide and a heater thereon; a semiconductor waveguide disposed on the second area, the semiconductor waveguide including a core layer and a cladding layer disposed on the core layer; a Mach-Zehnder modulator portion disposed on the first area, the Mach-Zehnder modulator portion including a first arm and a second arm; a buried region embedding the laser waveguide, the semiconductor waveguide, and the first and second arms; a groove disposed on the second area, the groove extending in a direction intersecting the waveguiding direction to across the semiconductor waveguide to the buried region; and a resin body disposed on the Mach-Zehnder modulator portion. The laser portion is optically coupled to the Mach-Zehnder modulator portion via the semiconductor waveguide. The groove has a bottom on a surface of the core layer of the semiconductor waveguide.

Quasi-phase matched (QPM), semiconductor photonic waveguides include periodically-poled alternating first and second sections. The first sections exhibit a high degree of optical coupling (abbreviated “X²”), while the second sections have a low X². The alternating first and second sections may comprise high-strain and low-strain sections made of different material states (such as crystalline and amorphous material states) that exhibit high and low X² properties when formed on a particular substrate, and/or strained corrugated sections of different widths. The QPM semiconductor waveguides may be implemented as silicon-on-insulator (SOI), or germanium-on-silicon structures compatible with standard CMOS processes, or as silicon-on-sapphire (SOS) structures.

The present invention provides a hybrid integrated optical module having a high coupling efficiency by suppressing a connection loss between waveguides. A hybrid integrated optical module according to an embodiment of the present invention is an optical module which integrates a semiconductor chip and a PLC chip. The semiconductor chip has a semiconductor waveguide and is mounted on a Si bench. The PLC chip includes a PLC substrate and an optical waveguide formed on the PLC substrate. An end face of the semiconductor chip protrudes from an end face of the Si bench toward the PLC chip side by a protrusion amount X. Gap adjustment (adjustment of a distance D) between the semiconductor waveguide and the optical waveguide becomes possible by setting a position where the end face of the semiconductor chip is brought into contact with an end face of the PLC chip to be a reference position (zero point).

A semiconductor TE/TM mode converter comprises a semiconductor waveguide layer including a compressive-strained first region and a tensile-strained second region, and a diffraction grating formed on the first region. The first region and second region are reversed-biased and forward-biased, respectively. TE mode light incident on the facet of the first region generates TM mode light outgoing from the facet of the second region. The diffraction grating in the first region has selective reflectance against TM mode light and reflects the TM mode light toward the second region, to lower the lasing threshold of TM mode light and raise the conversion efficiency.

An optical phase shifter (100) comprises a semiconductor waveguide (105) includes a core region (116) and a doped region (115a, 115b) containing free charges (electrons or holes), which can be steered into or removed from the wave guide, where an optical beam (150) propagates. A semiconductor structure (PN junction 112, 114) allows the control of the amount of free charges in the doped region, which constitutes a potential well. When the well is filled, the charges speed the beam propagation, introducing a phase change. When the well is emptied, (under application of a reverse bias to the junction 112, 114), the beam propagates with extra delay. The phase shifter allows very high speed modulation of the beam using low voltage and low power electronics. The device can be created using standard silicon processing techniques, and integrated with other optical components such as splitters and combiners to create amplitude modulators, attenuators and other optical devices.

In an integrated polarization splitting and rotating photonic device comprising at least one first waveguide; a second waveguide, both said waveguides extending from an input section to an output section; a top cladding; a bottom cladding and a symmetry-breaking layer so as to form an optical guiding structure in a wafer chip, said top and bottom claddings extending throughout the whole optical guiding structure sandwiching said waveguides therebetween, said symmetry-breaking layer extends in the optical guiding structure at least over the whole guiding structure length, and, at the input section, the at least one first waveguide core has a predetermined width through the optical guiding structure to the output section, receiving an input light signal, and further, the second waveguide core, both at the input and the output section, has a width narrower than said predetermined width of the first waveguide core; so that the optical guiding structure guides a first mode substantially confined within said at least one first waveguide core and a second mode substantially confined within said second semiconductor waveguide core said first and said second modes having the same polarization at the output section.

A system for all-optical signal regeneration is provided, which makes it possible to exhibit desired intensity noise suppressing function with respect to pulsed input signal light without increasing the injection current of semiconductor optical amplifiers even if the magnitude of nonlinear phase shift of the input signal light is less than π. The output light of the first delay interference unit is subjected to phase shift in the first nonlinear semiconductor waveguide and then, applied to the second delay interference unit along with the clock light. In the second delay interference unit, the first interfered light is generated from the output light while the second interfered light is generated from the clock light having an opposite logic to the input light. The second interfered light is subjected to phase shift by the first interfered light in the second nonlinear semiconductor waveguide and then, applied to the third delay interference unit. The third interfered light having an opposite logic to the input light is generated from the second interfered light in the third delay interference unit. The third interfered light is the output light of the system.

A transmitter for an optical device includes semi-conductor waveguides, each incorporating an electro-optic phase-shifter in the semi-conductor waveguide that is operable to change the refractive index of the waveguide to thereby introduce a phase shift in the light propagated through the waveguide. The electro-optic is connected to a phase shift controller and to a temperature measurement component, such as a PTAT circuit, that is integrated into the electronic or photonic chip carrying the waveguide. Temperature measurement by the measurement component can be multiplexed with the normal operation of the phase-shifter so that the temperature measurement function does not interfere with the phase shifting function.

An optical modulation device includes: a Mach-Zehnder modulator including a semiconductor waveguide; a plurality of phase modulators that are spaced from each other; a first amplifier that is coupled with an input transmission line transmitting an electrical signal, has an input impedance substantially equal to a characteristic impedance of the input transmission line; a first interconnection that is coupled to the first amplifier and transmits the electrical signal to a first end of one of the plurality of phase modulators that is provided on an input side of the Mach-Zehnder modulator; a second interconnection that is coupled to the first amplifier and transmits the electrical signal to a first end of the other of the plurality of phase modulators that is provided on an output side of the Mach-Zehnder modulator; and a plurality of termination resistors respectively coupled to second ends of the plurality of phase modulators.

A photonic integrated device (PID) for generating single and multiple wavelength optical signals is provided. The PID includes first and second reflective structures having first and second predetermined reflectivities, respectively. A common waveguide is optically coupled to the first reflective structure, and at least one semiconductor waveguide is optically coupled to the second reflective structure. The PID further includes at least one active gain region that is disposed between the first and second reflective structures. In various embodiments, the PID includes at least one of a dielectric waveguide based wavelength dependent element and a dielectric Bragg stack.

An electro-optic semiconductor device comprising a semiconductor waveguide with a core region within which is located at least one active area wherein the core of the waveguide outside of the one or more active areas are not contaminated by diffuse active area material and the one or more active area(s) and the waveguide are monolithic and are grown in an additive growth process. Also provided is a method of making an electro-optic semiconductor device, comprising the steps of; growing a first part of a core layer of a semiconductor waveguide, selectively growing an active layer over a partial area of the first part of the core layer, and growing a second part of the core layer of the semiconductor waveguide over the first part and the active layer, characterised in that the method comprises an additive growth process.