Hybrid Nanomaterials

Two of the hottest research topics today are hybrid nanomaterials and flexible electronics. As such, this book covers both topics with chapters written by experts from across the globe. Chapters address hybrid nanomaterials, electronic transport in black phosphorus, three-dimensional nanocarbon hybrids, hybrid ion exchangers, pressure-sensitive adhesives for flexible electronics, simulation and modeling of transistors, smart manufacturing technologies, and inorganic semiconductors

InP microdisks for optical signal processing and data transmission

The performance increase in telecommunication and computing systems demands an ever increasing input-output (IO) bandwidth and IO density, which can be met by integrated photonics. Using photonic integration, much higher densities of optical components can be achieved allowing for short-range optical communication systems in, e.g., high performance computers. The key functionalities required for these optical communication systems are light generation, light modulation and light detection. In addition to this other functionalities are also desirable, such as wavelength conversion. This thesis highlights the design and fabrication of indium phosphide (InP) microdisks heterogeneously integrated on silicon-on-insulator substrates. The fabrication of the microdisks in a laboratory clean-room environment is described. These devices can fulfil the above-mentioned functions required in optical communication. Experiments are then performed on the fabricated devices dealing with these various functionalities that are required for optical communication. The lasing properties of the devices are shown and simulated with a spatiallydependent rate equation model accurately predicting the device behaviour. A detailed speed analysis is given, including a parameter extraction of the devices. The operation of the devices as detectors is highlighted. Furthermore the PhD thesis provides a deep analysis of the use of InP microdisks as modulators. Besides the forward-biased operation principle using the free-carrier plasma-dispersion effect, also a high-speed reversely biased operation mode is proposed and demonstrated experimentally. The thesis also describes various approaches on how to improve the performance of the devices, in particular when using them as lasers. Ways how to increase the output power and how to enhance the operation speed are discussed. Because the device is strongly dependent on the coupling between the resonant InP cavity and the silicon waveguide, an extensive analysis of the coupling and the influence of certain process steps on the device performance are given. The PhD thesis concludes the work carried out on InP microdisks and gives an outlook about improving the device performance with respect to specific applications and how to further improve the manufacturability of the devices. Finally, for the InP microdisk-based devices an outlook is given about suitable applications, such as on-chip optical links for instance

A multiple-film magnetoresistive replay head, for audio applications.

Merged with duplicate record 10026.1/2548 on 27.03.2017 by CS (TIS)Sensors have been fabricated, which are able to read the information stored on magnetic tape using the anisotropic magnetoresistance effect. These have major advantages over conventional replay heads in that they are multi-track devices, with very small trackwidths. To overcome the signal limitation imposed by the reduced trackwidth the sensor consists of two long magnetoresistive elements which are folded together. By differentially sensing the magnetoresistive signal in each of the elements second harmonic distortion can be removed. To improve the linearity of the magnetoresistive response, the sensors are arranged in such a way that the sensor signal current in each of the elements provides the field necessary to correctly bias the head. A theoretical evaluation of the bias field for all configurations of element has been performed, and was found to fit experimental data. Sixteen tracks are provided across the width of a compact cassette tape, and the design specifically allows the finished sensors to be packaged using standard components. Several performance related features have been considered, and various other fabrication aids included on the photomasks used to build the sensors. These photomasks are provided by the S.E.R.C. from an original computer program written in a graphics language, which defines the size and shape of the various elements making up the device. The heads are fabricated using photolithographic methods, from thin films of several materials all of which are R.F. sputtered. To improve the performance of the sensors, various electro-magnetic properties of the magnetoresistive layers have been measured using apparatus built especially for the purpose. These properties have been optimised by varying the bias potential used in the sputtering process. The finished heads have been tested, and have been found to compare well with the theory derived to describe their performance.Magnetic Components Limited, Bridge Wharf, Chertsey, Surrey. KT16 8L