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This report describes the development of a computer model for the design of a laser seeker optical system. A laser seeker is a device that detects pulsed laser energy. The computer model is configured to design the seeker optics based on the following performance criteria: Sensitivity to laser energy, which can be related to target acquisition range; optical field of view; and seeker optics cross section area. The design is defined by four variables and a set of fixed parameters, and is configured using computer optimization with both a direct search and a random search being used. A superior design is selected from comparison of many sets of variables based on the value of an objective function made up of some of all of the performance criteria listed above and additional penalty factors applied for design constraint violations. The computer model contains design blocks for the detector, the preamplifier, and the optical elements of the seeker. There is also a computer ray trace routine to evaluate optical performance. The model was run with roar different objective functions, and the resulting seeker designs were analyzed. A detail listing of the computer program is contained in Appendix B.

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Yes / This paper proposes a new solution to improve the performance parameters of on-chip antenna designs on standard CMOS silicon (Si.) technology. The proposed method is based on applying the metasurface technique and exciting the radiating elements through coupled feed mechanism. The on-chip antenna is constructed from three layers comprising Si.-GND-Si. layers, so that the ground (GND) plane is sandwiched between two Si. layers. The silicon and ground-plane layers have thicknesses of 20μm and 5μm, respectively. The 3×3 array consisting of the asterisk-shaped radiating elements has implemented on the top silicon layer by applying the metasurface approach. Three slot lines in the ground-plane are modelled and located directly under the radiating elements. The radiating elements are excited through the slot-lines using an open-circuited microstrip-line constructed on the bottom silicon layer. The proposed method to excite the structure is based on the coupled feeding mechanism. In addition, by the proposed feeding method the on-chip antenna configuration suppresses the substrate losses and surface-waves. The antenna exhibits a large impedance bandwidth of 60GHz from 0.5THz to 0.56THz with an average radiation gain and efficiency of 4.58dBi and 25.37%, respectively. The proposed structure has compact dimensions of 200×200×45μm3. The results shows that, the proposed technique is therefore suitable for on-chip antennas for applications in system-on-chip for terahertz (THz) integrated circuits. / Innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424; UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E0/22936/1.

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The National Scientific Balloon Facility (NSBF) conducts scientific balloon flights. Scientific payloads ranging from a few hundred up to several thousand pounds suspended weight are flown over the southern United States. People living in these areas are subject to risk from these operations. A model has been developed to predict the risk associated with the ascent phase of a balloon operation. This model includes all of the significant factors that affect ascent phase risk. The model is automated in a computer program whose input contains all of the parameters and factors for a particular mission. The results of this model can be used to advise management personnel of the risk level for a particular balloon mission. This model can be used as a long range planning tool or on the day of launch to determine whether the mission risk level is acceptable. / Master of Science

Ce mémoire porte sur un laser modulable temporellement et accordable en longueur d'onde dans l'infrarouge moyen pour répondre à une application de contre-mesure pour la protection des plateformes aériennes. Il est constitué d'une source délivrant des impulsions femtosecondes (fs) à une longueur d'onde d'environ 2.8 micromètres (µm) et d'un système d'autodécalage en longueur d'onde par effet Raman. Ce dernier est l'objet à concevoir dans le cadre du présent projet de maîtrise. Le chapitre 1 décrit ainsi le fonctionnement de quatre générations d'auto-directeur (AD) infrarouge, dont trois étaient assujettis à des simulations des effets lasers en laboratoire, tel que présenté au chapitre 4. Le chapitre 2 couvre la théorie essentielle et certaines astuces qui ont permis de concevoir le laser présenté au chapitre 3. La physionomie du système d'autodécalage conçu permet l'amplification des impulsions fs de la source laser, grâce à une fibre optique de verre fluoré dopée à l'erbium, en plus de l'autodécalage en longueur d'onde jusqu'à 4.8 µm à l'aide d'une fibre optique de fluoroindate. De plus, le système d'autodécalage est entièrement fibré pour des raisons de robustesse, il est opérable à des taux de répétition de plus de 100 hertz et il permet une émission jusqu'à 1.1 watts de puissance laser sur toute la plage de longueurs d'onde. Ces performances étaient nécessaires pour contrecarrer efficacement trois émulateurs d'AD : un à balayage conique, un à double-bande spectrale et un imageant. / This dissertation focuses on a mid-infrared modulated and wavelength-tunable laser for countermeasure applications. This laser source is based on a seed laser, which emits femtoseconds (fs) pulses at a central wavelength of 2.8 microns (µm), and a soliton self-frequency shift (SSFS) system. The conception of the latter is the goal of the project. Chapter 1 then introduces four generations of infrared seekers, three of which were emulated and tested in laboratories, as presented in chapter 4. Chapter 2 develops fundamental concepts as well as conception tips that helped build the laser presented in chapter 3. The SSFS system amplifies fs pulses from the seed laser, with the help of an erbium doped fluoride optical fibre, and shifts their wavelengths up to 4.8 µm using a fluoroindate fiber. The SSFS system is all-fibre for better robustness, it can be operated beyond 100 hertz and it allows for delivering a laser power up to 1.1 watts for the whole emission spectrum. These performances were mandatories for sufficiently neutralizing the three following IR seeker emulators: a conical scanner, a dual band scanner and an imaging system.