Proof Of Concept Device Research Articles

Optical Microwave and Millimeter Generation by Using Birefringent Fiber FP Cavity with Pulse Laser Injection

A novel optical microwave and millimeter generation by using single mode fiber FP cavity (SMFFPC) with pulse laser injection is proposed and experimentally demonstrated. The frequency of output signal is determined by the birefringence degree of the SMFFPC, a general relationship between output signal frequency of SMFFPC and birefringence degree of single mode fiber is derived. The proof of concept device consists of a light source, a polarizer controller, a modulator, a RF generator, a single mode fiber Fabry-Perot cavity, a strain inspector, an erbium doped fiber amplifier, a filter, a polarizer, and a digital communication analyzer. The results demonstrate the new concept of optical microwave and millimeter generation and the technical feasibility.

Double-barrier long wavelength SiGe/Si heterojunction internal photoemission infrared photodetectors

This work studies the effect of a double barrier on the photoresponse spectrum of SiGe/Si heterojunction internal photoemission infrared photodetectors. Results are compared with those of a single barrier sample which has nominally the same parameters. It is shown that the cut-off wavelength of the multi-barrier device depends on the operating temperature; therefore, it can be tuned to the desired region within the device capacity by changing the device temperature. The proof of concept device, which has two Si1-xGex/Si junctions with x=0.1 and x=0.23, allows the tuning of the cut-off wavelength from 19.9 μm to 11.7 μm for 10 K and 50 K, respectively.

Light Emitting Polymermaterials: the Working Base for Flexible Full Color Displays

AbstractIn the last few years, industrial research into materials fulfilling the needs of the maturing OLED display industry has intensified considerably. A first generation of polymers (phenyl- PPVs) is now being commercially exploited in first monochrome polymer LED display applications. Based on these materials, non-planar displays have already been demonstrated. However, those proof of concept devices have been monochrome. Especially the RGB materials need considerable improvement to be suitable for flexible full color displays.We will therefore report on the progress in the development of polymers for red, green, and blue emission. Our main focus here is on improving the properties of various polymers derived from the spiro-bifluorene core.Depending on the color, the main issues vary strongly: For BLUE polymers, efficiency, color coordinates, and processibility are already at a commercial level while operational lifetime still needs strong improvement. RED materials are in an almost contrary situation: here, the operational lifetime is excellent, whereas the efficiency and the driving current are requiring further improvement. For GREEN, achieving saturated emission, whilst maintaining the other properties (high efficiency, long operational lifetime), is still challenging. We will demonstrate the current status of material development within Covion.In addition, we achieved advances in full-color patterning, especially techniques based on Ink-Jet printing. This technology potentially allows the efficient manufacturing of high resolution RGB devices on a variety of substrates, including flexible layers.

Niobium-copper superconductor-normal metal-superconductor asymmetry modulated SQUIDs

We have developed a fabrication method using a focused ion beam microscope that allows us to produce SNS junctions in which thermally energetic electrons can enter the N region. We report on SQUIDs made with this technique which we are developing as proof of concept devices and prototype high energy resolution spectrometers. We discuss the various design parameters used for our devices and present results from our prototype SQUIDs. We present results for devices with a variety of N-electrode structures and discuss their suitability for our application.

Light propagation, optical modulation, and beam steering in waveguides with quantum well voltage tunable claddings

We present results on devices fabricated in a waveguide system utilizing a voltage tunable quantum well cladding layer. A (GaAs/AlGaAs) beam steering device produced an angular shift of 2.4° under an applied voltage of 20 V. It is shown numerically that electro-optic modulators fabricated in such a material configuration can have simultaneously improved contrast ratios and insertion losses if the ratio of light propagating in the cladding and in the core regions can be controlled. A proof of concept device is demonstrated in which an electric field is used to change the distribution of light propagating in the waveguide.

Design and installation of instruments in the Westinghouse LCP coil

The Westinghouse Electric Corporation completed the Nb 3 Sn Superconducting toroidal field coil for the Large Coil Program (LCP) which is being managed by the Oak Ridge National Laboratory (ORNL). The coil design which features a force flow cooled conductor and a distributed aluminum plate structure has been described elsewhere [1,2,3,4]. A large number of instruments were installed in the coil because it is a first of its kind proof of concept device. This paper describes the installation of various sensors in the Westinghouse LCP coil.