Abstract: A tunable optical filter utilizes multiple electroholographic (EH) gratings with different center wavelengths to filter an optical signal over a wide wavelength range. The EH gratings are connected such that an input optical signal passes through at least one of the EH gratings. The EH gratings are activated and tuned by electrode pairs that are controlled through a voltage controller. The tunable optical filter is coarse tuned by activating the EH gratings having a wavelength range that includes the center wavelength that is to be filtered and fine tuned by adjusting the voltage that is applied across the activated EH gratings.

Abstract: Optical systems for selectively altering the propagation of light are provided. A representative optical system incorporates an optical device that includes a first para-electric holographic medium. The first para-electric holographic medium stores a first hologram that can exhibit a first active mode. The first hologram exhibits the first active mode when a first electric field is applied to the first para-electric holographic medium. When in the first active mode, the first hologram directs light incident upon the first holographic medium to a first location. Methods and other systems also are provided.

Abstract: An electronic device comprising a population of quantum dots embedded in a host matrix and a primary light source which causes the dots to emit secondary light of a selected color, and a method of making such a device. The size distribution of the quantum dots is chosen to allow light of a particular color to be emitted therefrom. The light emitted from the device may be of either a pure (monochromatic) color, or a mixed (polychromatic) color, and may consist solely of light emitted from the dots themselves, or of a mixture of light emitted from the dots and light emitted from the primary source. The dots desirably are composed of an undoped semiconductor such as CdSe, and may optionally be overcoated to increase photoluminescence.

Abstract: The present disclosure relates to an optical cavity, comprising a first non-concave reflector positioned at a first end of the optical cavity and a second non-concave reflector positioned at a second end of the optical cavity that receives and reflects light reflected from the first non-concave reflector. The first non-concave reflector is configured to focus light that reflects off of the reflector back upon itself to avoid diffraction losses from the optical cavity. In one embodiment of the invention, the first non-concave reflector includes a layer of material that has a thickness that vanes as a function of radial distance out from an axial center of the layer. In another embodiment of the invention, the first non-concave reflector includes a layer of material that has an index of refraction that varies as a function of radial distance out from an axial center of the layer.

Abstract: A light emitting device and a method of fabricating the device include a wavelength selective reflector that is formed between a light source and a layer of phosphorescent material. The light emitting device is a phosphor-conversion light emitting diode (LED) that outputs secondary light that is converted from primary light emitted from the light source. In the preferred embodiment, the light source is a Gallium Nitride (GaN) die and the wavelength selective reflector is a distributed Bragg reflector (DBR) mirror. The DBR mirror is comprised of multiple alternating layers of high and low refractive index materials. The high refractive index material may be Titanium Dioxide (TiO.sub.2) and the low refractive index material may be Silicon Dioxide (SiO.sub.2). An encapsulating layer over the GaN die provides a distance between the GaN die and the DBR mirror. Preferably, the encapsulating layer is a dome-shaped structure and the DBR mirror forms a dome-shaped shell over the encapsulating layer.

Abstract: This disclosure provides an electroluminescent ("EL") display device having anode, cathode, insulator and organic EL layers. The anode and cathode layers sandwich the other two layers, and the insulator layer is patterned to selectively block flow of current through the EL layers, and thereby locally block generation of light. The patterned insulator layer allows a single panel to display multiple visual attributes, yet does not require electrode patterning. The patterned insulator can be fabricated using photoresist exposure and development procedures. The photoresist is laid on top of a commercially available substrate/electrode layered pair, and is developed to create an assembly that can be completed in a single vacuum deposition process.

Abstract: A high refractive index package material is described that encapsulates a semiconductor light emitting chip. The high refractive index package material is transparent to the light emitted from the chip and includes a host material and a plurality of nanoparticles held in the host material. The host material has a refractive index lower than that of the chip and is transparent to the light emitted from the chip. The nanoparticles are (1) formed from a material having a refractive index higher than that of the host material, (2) substantially smaller in size than the wavelength of the light emitted from the chip, (3) included in the host material at such a density that the effective refractive index of the high refractive index package material is higher than that of the host material without decreasing the transparency of the high refractive index package material.

Abstract: An organic electroluminescent device with a conducting polymer layer beneath the hole transport layer. A conducting polymer layer of doped polyaniline (PANI) is spin-cast onto an indium-tin oxide (ITO) anode coating on a glass substrate. Then a hole transport layer, for example TPD or another aromatic tertiary amine, is vapor-deposited onto the conducting polymer layer, followed by an electron transport layer and a cathode. Polyester may be blended into the PANI before spin-casting and then removed by a selective solvent after the spincasting, leaving a microporous layer of PANI on the anode. The conducting polymer layer may instead be made of a .pi.-conjugated oxidized polymer or of TPD dispersed in a polymer binder that is doped with an electron-withdrawing compound. An additional layer of copper-phthalocyanine, or of TPD in a polymer binder, may be disposed between the conducting polymer layer and the hole transport layer.

Abstract: A method for processing coplanar semiconductor devices of different types as provided. The method includes the steps of: forming a first layer for formation of a first device region on a substrate, forming an epitaxial semiconductor lift-off layer above the first device region, removing a portion of the first device region to open areas for the formation of the second device region, depositing epitaxially a second device region, and removing the liftoff layer to leave the first and second device regions remaining on the substrate.

Abstract: A molecular beam epitaxy (MBE) process in which some portions of the substrate are shadowed by a shadow mask from receiving at least one of the molecular beams used in the MBE process. This process is capable of producing NIPI superlattices that have selective contacts that are far superior to those which can be produced at present. This technique can also produce a wide variety of NIPI devices as well as other types of IC structures.