Abstract: An asymmetric twin waveguide (ATG) structure with an integrated amplifier and detector fabricated in a single active waveguide layer is disclosed. The structure comprises an active waveguide layer formed on a passive waveguide layer. The active and passive waveguides have different effective indices of refraction such that a first mode of light is confined primarily to the active waveguide and a second mode of light is confined primarily to the passive waveguide in the area where the waveguides overlap.

Abstract: An asymmetric twin waveguide (ATG) structure with quantum-well intermixing in the taper region of the active waveguide is disclosed. The structure comprises a first waveguide, a second waveguide, and a taper formed in the second waveguide. The taper has an intermixed area formed therein comprising a plurality of quantum wells intermixed with a plurality of barriers. The quantum wells and barriers may be intermixed using plasma-enhanced intermixing such as, for example, Argon plasma enhanced intermixing. Quantum-well intermixing reduces absorption loss normally encountered in the movement of light between waveguides.

Abstract: An asymmetric twin waveguide (ATG) structure is disclosed that significantly reduces the negative effects of inter-modal interference in symmetric twin-waveguide structures and which can be effectively used to implement a variety of optical devices. The ATG structure of the invention can be monolithically fabricated on a single epitaxial structure without the necessity of epitaxial re-growth. To achieve the ATG structure of the invention, the effective index of the passive waveguide in the ATG is varied from that of a symmetric twin waveguide such that one mode of the even and odd modes of propagation is primarily confined to the passive waveguide and the other to the active waveguide. The different effective indices of the two coupled waveguides result in the even and odd modes becoming highly asymmetric. As a result, the mode with the larger confinement factor in the active waveguide experiences higher gain and becomes dominant.

Abstract: An optoelectronic device and a method of fabricating a photosensitive optoelectronic device includes depositing a first organic semiconductor material on a first electrode to form a continuous first layer having protrusions, a side of the first layer opposite the first electrode having a surface area at least three times greater than an underlying lateral cross-sectional area; depositing a second organic semiconductor material directly on the first layer to form a discontinuous second layer, portions of the first layer remaining exposed; depositing a third organic semiconductor material directly on the second layer to form a discontinuous third layer, portions of at least the second layer remaining exposed; depositing a fourth organic semiconductor material on the third layer to form a continuous fourth layer, filling any exposed gaps and recesses in the first, second, and third layers; and depositing a second electrode on the fourth layer, wherein at least one of the first electrode and the second electrode

Abstract: An asymmetric twin waveguide (ATG) structure is disclosed that significantly reduces the negative effects of inter-modal interference in symmetric twin-waveguide structures and which can be effectively used to implement a variety of optical devices. The ATG structure of the invention can be monolithically fabricated on a single epitaxial structure without the necessity of epitaxial re-growth. To achieve the ATG structure of the invention, the effective index of the passive waveguide in the ATG is varied from that of a symmetric twin waveguide such that one mode of the even and odd modes of propagation is primarily confined to the passive waveguide and the other to the active waveguide. The different effective indices of the two coupled waveguides result in the even and odd modes becoming highly asymmetric. As a result, the mode with the larger confinement factor in the active waveguide experiences higher gain and becomes dominant.

Abstract: Organic light emitting devices are described wherein the emissive layer comprises a host material containing an emissive molecule, which molecule is adapted to luminesce when a voltage is applied across the heterostructure, and the emissive molecule is selected from the group of phosphorescent organometallic complexes, including cyclometallated platinum, iridium and osmium complexes. The organic light emitting devices optionally contain an exciton blocking layer. Furthermore, improved electroluminescent efficiency in organic light emitting devices is obtained with an emitter layer comprising organometallic complexes of transition metals of formula L2MX, wherein L and X are distinct bidentate ligands. Compounds of this formula can be synthesized more facilely than in previous approaches and synthetic options allow insertion of fluorescent molecules into a phosphorescent complex, ligands to fine tune the color of emission, and ligands to trap carriers.

Abstract: Light emitting devices having charge transporting layers comprising one or more metal complexes are provided. More particularly, devices include hole transporting layers comprising at least one organometallic complex are disclosed. The present devices can further comprise an electron blocking layer for improved efficiency.

Abstract: The present invention relates to efficient organic light emitting devices (OLEDs) doped with multiple light-emitting dopants, at least one dopant comprising a phosphorescent emitter, in a thin film emissive layer or layers. The present invention is directed to an efficient phosphorescent organic light emitting device utilizing a plurality of emissive dopants in an emissive region, wherein at least one of the dopants is a phosphorescent material. Thus, the present invention provides an organic light emitting device comprising an emissive region, wherein the emissive region comprises a host material, and a plurality of emissive dopants, wherein the emissive region is comprised of a plurality of bands and each emissive dopant is doped into a separate band within the emissive region, and wherein at least one of the emissive dopants emits light by phosphorescence.

Abstract: Organic light emitting devices are Disclosed which are comprised of a heterostructure for producing electroluminescence wherein the heterostructure is comprised of an emissive layer containing a phosphorescent dopant compound.

Abstract: Organic light emitting devices are disclosed, which comprise a heterostructure for producing electroluminescence, wherein the heterostructure comprises an emissive layer containing a phosphorescent dopant compound.

Abstract: Light emitting devices having blocking layers comprising one or more metal complexes are provided. The blocking layers may serve to block electrons, holes, and/or excitons. Preferably, the devices further comprise a separate emissive layer in which charge and/or excitons are confined. Metal complexes suitable for blocking layers can be selected by comparison of HOMO and LUMO energy levels of materials comprising adjacent layers in devices of the present invention.

Abstract: An organic light emitting device (OLED) is disclosed for which the hole transporting layer, the electron transporting layer and/or the emissive layer, if separately present, is comprised of a non-polymeric material. A method for preparing such OLED's using vacuum deposition techniques is further disclosed.

Abstract: A plurality of layers of a first semiconductor material and a plurality of dots-in-a-fence barriers disposed in a stack between a first electrode and a second electrode. Each dots-in-a-fence barrier consists essentially of a plurality of quantum dots of a second semiconductor material embedded between and in direct contact with two layers of a third semiconductor material. Wave functions of the quantum dots overlap as at least one intermediate band. The layers of the third semiconductor material are arranged as tunneling barriers to require a first electron and/or a first hole in a layer of the first material to perform quantum mechanical tunneling to reach the second material within a respective quantum dot, and to require a second electron and/or a second hole in a layer of the first semiconductor material to perform quantum mechanical tunneling to reach another layer of the first semiconductor material.

Abstract: A photosensitive cell includes an anode and a cathode; a donor-type organic material and an acceptor-type organic material forming a donor-acceptor junction connected between the anode and the cathode; and an exciton blocking layer connected between the acceptor-type organic material of the donor-acceptor junction and the cathode, the blocking layer consisting essentially of a material that has a hole mobility of at least 10?7 cm2/V-sec or higher, where a HOMO of the blocking layer is higher than or equal to a HOMO of the acceptor-type material.

Abstract: A monolithic wavelength stabilized system comprises a laser monolithically formed with a waveguide splitter having at least two branches. Non-identical resonators having different wavelengths are operatively coupled to each branch of the splitter and a photodiode is communicatively coupled to receive the output from each non-identical resonator. A control unit receives the photocurrent outputs from the photodiodes, determines based on the photocurrents whether the wavelength of the laser signal is at a desired value, and transmits a feedback signal to the laser to move the laser output toward the desired wavelength. The laser, splitter, resonators, and photodiodes are monolithically formed in a single chip using asymmetric waveguides.

Abstract: An organic photosensitive optoelectronic device having a plurality of cells disposed between a first electrode and a second electrode. Each cell includes a photoconductive organic hole transport layer adjacent to a photoconductive organic electron transport layer. A metal or metal substitute is disposed between each of the cells. At least one exciton blocking layer is disposed between the first electrode and the second electrode.

Abstract: A photoactive fiber is provided, as well as a method of fabricating such a fiber. The fiber has a conductive core including a first electrode. An organic layer surrounds and is electrically connected to the first electrode. A transparent second electrode surrounds and is electrically connected to the organic layer. Other layers, such as blocking layers or smoothing layers, may also be incorporated into the fiber. The fiber may be woven into a cloth.

Abstract: The present invention is directed to multi-layer organic devices having improved stability, wherein at least one layer of the device comprises a host material that is morphologically unstable and a dopant material that provides improved morphological properties to the layer. The layer may be incorporated into, for example, OLEDs, organic phototransistors, organic photovoltaic cells, and organic photodetectors.

Abstract: An organic light emitting device structure includes a substrate, a first electrically conductive layer formed over the substrate wherein the first electrically conductive layer has a positive polarity, and a transparent organic light emitting device formed over the first electrically conductive layer. The structure also includes a transparent electrically conductive metal layer formed over the transparent organic light emitting device wherein the metal has a work function less than 4 eV, and a second electrically conductive layer formed over the transparent electrically conductive metal layer, wherein the second electrically conductive layer has a negative polarity, and wherein the second electrically conductive layer comprises a material selected from the group consisting of a transparent electrically conductive oxide and a transparent electrically conductive polymer.

Abstract: An organic photosensitive optoelectronic device optimized to enhance desired characteristics such as external quantum efficiency is described. The photosensitive optoelectronic device has at least two transparent electrodes and one or more organic photoconductive layers disposed between the transparent electrodes. In other embodiments photosensitive optoelectronic devices with multilayer photoconductive structures and photosensitive optoelectronic devices with a reflective layer are disclosed.