Abstract: A semiconductor monolithic transmitter photonic integrated circuit (TxPIC) comprises two different situations, either at least one signal channel in the PIC having a modulated source with the channel also extended to include at least one additional element or a plurality of modulated sources comprising N signal channels in the PIC of different transmission wavelengths, where N is equal to or greater than two (2), which may also approximate emission wavelengths along a standardized wavelength grid. In these two different situations, a common active region for such modulated sources and additional channel elements is identified as an extended identical active layer (EIAL), as it extends from a single modulated source to such additional channel elements in the same channel and/or extends to additional modulated sources in separate channels where the number of such channels is N equal to two or greater.

Abstract: A method provides acceptable performance from a semiconductor transmitter photonic integrated circuit (TxPIC) that contains a plurality of modulated sources each comprising a laser source and an external modulator where each laser source provides a different emission wavelength and each modulated source forms a separate signal channel, comprising the steps of providing at least some of the signal channels with an extended identical active layer (EIAL) so that the modulated sources each have an identical active region wavelength and detuning the laser emission wavelength in each laser source within the EIAL from the laser active region wavelength.

Abstract: Consistent with the present disclosure, a current blocking layer is provided between output waveguides carrying light to be sensed by the photodiodes in a balanced photodetector, and the photodiodes themselves. Preferably, the photodiodes are provided above the waveguides and sense light through evanescently coupling with the waveguides. In addition, the current blocking layer may include alternating p and n-type conductivity layers, such that, between adjacent ones of such layers, a reverse biased pn-junction is formed. The pn-junctions, therefore, limit the amount of current flowing from one photodiode of the balanced detector to the other, thereby improving performance.

Abstract: Consistent with the present disclosure, a current blocking layer is provided between output waveguides carrying light to be sensed by the photodiodes in a balanced photodetector, and the photodiodes themselves. Preferably, the photodiodes are provided above the waveguides and sense light through evanescently coupling with the waveguides. In addition, the current blocking layer may include alternating p and n-type conductivity layers, such that, between adjacent ones of such layers, a reverse biased pn-junction is formed. The pn-junctions, therefore, limit the amount of current flowing from one photodiode of the balanced detector to the other, thereby improving performance.

Abstract: A monolithic photonic integrated circuit (PIC) chip where the active waveguide cores of the modulated sources of the PIC are multiple quantum wells (MQWs) and the passive waveguide cores of an optical combiner are a bulk layer or material. The cores of the waveguide cores may be a quaternary such as InGaAsP or InAlGaAs.

Abstract: The Group III–V quaternary, InAlGaAs is employed as a waveguide layer in optical components, such as In-P based array waveguide gratings (AWGs), avalanche photodiodes (APDs) or other optical components that contain a waveguide core in the InP regime. The deployment of InAlGaAs waveguides provides for high uniform photoluminescent (PL) emission wavelength across the wafer for InAlGaAs waveguides as compared to InGaAsP waveguides as now commonly employed in such optical devices or components. The use of an InAlGaAs waveguide core has particular utility when deployed in a photonic integrated circuit (PIC) such as an AWG with a plurality of outputs optically integrated with a plurality of photodetectors, such as APDs which are exemplified in this disclosure. In lieu of an InAlGaAs waveguide, combination layers of InGaAs/InAlAs, InGaAs/InAlGaAs or InAlAs/InAlGaAs may be employed or stacks of such layers to form the waveguides in the PIC chip.

Abstract: A monolithic photonic integrated circuit (PIC) chip comprises an array of modulated sources providing a plurality of channel signals of different wavelengths and an optical combiner coupled to receive the channel signals and produce a combined output of the channel signals. The arrays of modulated sources are formed as ridge waveguides to enhance the output power from the respective modulated sources so that the average output power from the sources is approximately 2 to 4 times higher than in the case of comparable arrays of modulated sources formed as buried waveguides.

Abstract: The Group III-V quaternary, InAlGaAs is employed as a waveguide layer in optical components, such as In-P based array waveguide gratings (AWGs), avalanche photodiodes (APDs) or other optical components that contain a waveguide core in the InP regime. The deployment of InAlGaAs waveguides provides for high uniform photoluminescent (PL) emission wavelength across the wafer for InAlGaAs waveguides as compared to InGaAsP waveguides as now commonly employed in such optical devices or components. The use of an InAlGaAs waveguide core has particular utility when deployed in a photonic integrated circuit (PIC) such as an AWG with a plurality of outputs optically integrated with a plurality of photodetectors, such as APDs which are exemplified in this disclosure. In lieu of an InAlGaAs waveguide, combination layers of InGaAs/InAlAs, InGaAs/InAlGaAs or InAlAs/InAlGaAs may be employed or stacks of such layers to form the waveguides in the PIC chip.

Abstract: A monolithic photonic integrated circuit (PIC) chip comprises an array of modulated sources providing a plurality of channel signals of different wavelengths and an optical combiner coupled to receive the channel signals and produce a combined output of the channel signals. The arrays of modulated sources are formed as ridge waveguides to enhance the output power from the respective modulated sources so that the average output power from the sources is approximately 2 to 4 times higher than in the case of comparable arrays of modulated sources formed as buried waveguides.

Abstract: A photodetector and a method of manufacture therefor. The photodetector includes a waveguide located over a photodetector substrate and a resonant coupler located over and coupled to the waveguide. An index of refraction of the resonant coupler is greater than an index of refraction of the waveguide. The photodetector also includes an absorber located over and coupled to the resonant coupler, wherein the absorber has an index of refraction greater than the index of refraction of the resonant coupler.

Abstract: The total base-collector capacitance of a double-heterostructure bipolar transistor device is reduced by removing semiconductor material from the extrinsic regions and replacing the removed material with a relatively-low-dielectric-constant material, The base-collector capacitance is further reduced by using a composite subcollector structure that permits the extrinsic regions to be made thicker than the intrinsic region of the device.

Abstract: An optical network unit designed to be connected to incoming and outgoing fibers at a customer location is made in integrated-circuit form. One portion of the integrated circuit includes a thin-film waveguiding layer and functions as an optical splitter, a photodetector and a modulator. Another portion of the circuit serves as an amplifier..

Abstract: The present invention is directed at an electrically tunable filter for wavelength filtering of light. The filter comprises a substrate region, a waveguide region over the substrate, an upper region over the waveguide region, and current blocking regions adjacent to the waveguide region. The waveguide region comprises a semiconductor having a bandgap wavelength sufficiently different from the light for high peak transmission of the light. A waveguide rib layer may also be included in the waveguide region to channel the light through the filter. The current blocking regions narrow the waveguide region to increase the current density. The present invention is also directed at a method of manufacturing the filter described above.

Abstract: A monolithically integrated electroabsorption modulator/optical amplifier is described which is prepared using a lateral bandgap control technique with a planar III-V compund semiconductor substrate. The described device evidences a bandgap shift in excess of 60 nanometers, so indicating its applicability for integration of modulators and lasers or amplifiers. The device is fabricated by atmospheric pressure metal organic condensed vapor deposition growth of gallium indium arsenise/gallium indium aresenide phosphide strained quantum wells on ridges deposited on the substrate.

Abstract: Semi-insulating epitaxial layers of Group III-V based semiconductor compounds are produced by a MOCVD process through the use of organic titanium-based compounds. Resistivities greater than 1.times.10.sup.7 ohm/cm have been achieved.

Abstract: High-power, single transverse mode laser operation is achieved in an extended-cavity structure by combining a semiconductor gain medium having a large optical cavity together with a length of single mode optical fiber between first and second reflector surfaces. The first reflector surface is formed on an end facet of the semiconductor gain medium; the second reflector surface is formed on an end of the optical fiber. Output power is efficiently coupled from the fiber end of the extended-cavity laser to a standard transmission medium.

Abstract: Semi-insulating epitaxial layers of Group III-V based semiconductor compounds are produced by an MOCVD process through the use of bis arene titanium sources, such as cyclopentadienyl cycloheptatrienyl titanium and bis (benzene) titanium.

Abstract: High resistivity Ti-doped Group III-V-based MOCVD layers are used to constrain current to flow through the active region of a variety of devices such as CSBH and DCPBH lasers.

Abstract: Low loss semiconductor waveguides for supporting propagation of optical signals over a wide range of wavelengths are achieved by growing at least two epitaxial layers of dopant material contiguous along a major surface of each layer to form a heterointerface therebetween. At least one of the epitaxial layers includes a sufficient concentration of semiconductor material to cause strain via lattice mismatch substantially at and near the heterointerface. The strain induces a change in refractive index such that the heterointerface exhibits a substantially higher refractive index than a portion of each epitaxial layer proximate to the heterointerface. The resulting waveguide is capable of supporting propagation of optical signals substantially along the heterointerface. In one example, contiguous epitaxial layers of InP and InGaP form a waveguide for optical signals at wavelengths greater than 0.93 .mu.m. The concentration of Ga in the InGaP epitaxial layer is varied from 10.sup.18 to 10.sup.20 cm.sup.

Abstract: High speed, high quantum efficiency, low dark current, and avalanche gain greater than 10 are exhibited by a long wavelength avalanche photodetector including in succession a terminal region of p-type indium phosphide (InP) a multiplication region comprising first and second layers of n-type indium phosphide (InP), a grading layer of n-type indium gallium arsenide phosphide (InGaAsP), and an absorption region of n-type indium gallium arsenide (InGaAs).