A polarization-independent electro-optically tunable add/drop filter utilizing non-polarizing novel relaxed beam splitters has been developed in LiNbO3 at the 1.55μm wavelength regime. The operation of this filter is based on passive directional coupler type beam splitters and strain-induced phase-matched TE↔TM polarization mode converters on an asymmetric Mach-Zehnder interferometer waveguide configuration. Fabrication parameters for channel waveguides, relaxed beam splitters and polarization mode converters were optimized individually then integrated to produce the final device. Single mode channel waveguides for both TE and TM polarizations were realized by the diffusion of 7μm wide Ti strips into LiNbO3 substrate. Relaxed beam splitters were produced using Ti diffused waveguides in a directional coupler configuration with 3.5mm long coupling region, 0.6º bending angle, and separation gap of 11μm and 13μm between waveguides. Tunable TE↔TM polarization mode converters with 99.8%

A polarization-independent electro-optically tunable add/drop filter utilizing non-polarizing novel relaxed beam splitters has been developed in LiNbO3 at the 1.55μm wavelength regime. The operation of this filter is based on passive directional coupler type beam splitters and strain-induced phase-matched TE↔TM polarization mode converters on an asymmetric Mach-Zehnder interferometer waveguide configuration. Fabrication parameters for channel waveguides, relaxed beam splitters and polarization mode converters were optimized individually then integrated to produce the final device. Single mode channel waveguides for both TE and TM polarizations were realized by the diffusion of 7μm wide Ti strips into LiNbO3 substrate. Relaxed beam splitters were produced using Ti diffused waveguides in a directional coupler configuration with 3.5mm long coupling region, 0.6º bending angle, and separation gap of 11μm and 13μm between waveguides. Tunable TE↔TM polarization mode converters with 99.8%

Multiport beam splitter is a new research topic in quantum communication. To improve the security system, the dimension/capacity of quantum communication should increase. In this thesis, design, simulation and methodology of NXN multiport beam splitter on a photonic integrated circuit is explained. Photonic integrated circuit has more advantages than other optical components to design a multiport beam splitter. Multiport beam splitter on a photonic chip gives configuration stability, a compact prototype for future quantum network.

Due to the property of the photonic crystal, like bandgap, many researches on them are discussed. Photons with wavelength within the bandgap cannot propagate through the crystal. Then placing some defects in the crystal, because the periodic arrangement is destroyed, it is possible to build a waveguide to guide light along certain path. One kind is coupled cavity waveguide. The photons can propagate in a coupled-cavity waveguide by coupling without radiation losses. So it is widely used to implement a variety of optical devices. In this thesis, we use coupled cavity waveguide to construct devices. And the characteristics of Mach-Zehnder interferometer and power splitter are discussed. Then we propose two logic gate structures with an input port and two control ports. The state of control port determines the electric field at the output port. Besides, the four-port channel drop filter is proposed. It will make the three wavelengths ¢w1310, 1490 and 1550 nm¢w propagate in different waveguides. So it could be used as a wavelength demultiplexer for FTTH. Finally, the property of the PC-based rat-race circuit is investigated. By adjusting the phase of the control signal, we could decide the input signal to exit from output 1 or output 2. In this way, we could use it to function as a switch.

Parkinson's disease (PD) is a progressive, neurological movement disorder. The stability of eye movements in PD is not well understood but many patients report difficulty doing tasks that require stabilized fixation and gaze. The ability to stabilize an image on the retina is critical is acquiring visual information. The purpose of this study was to compare the stability of fixational eye movements of PD patients to those of age-matched controls. Eye movements during simple fixation tasks were recorded from 66 subjects (ages 52 to 84), and 36 age-matched controls (ages 58-85). The absolute velocity of the fixational eye movements were recorded and correlated to a clinical measure of disease progression as measured by the Unified Parkinson's Disease Rating Scale (UPDRS). Unstable, non-rhythmic eye movements were seen in the PD patients. There were significant differences in the absolute velocity and standard deviation between the control group and the PD group in both the horizontal and vertical directions. The correlation of the absolute velocity to the UPDRS was not significant. Parkinson's disease does appear to affect the stability of eye movements. The instabilities in the eye movements appear to precede body tremor. This could lead to an early method for diagnosis and analysis of the disease.

Polarization dependences of optical devices in highly-integrated optical systems become a major problem. To overcome this issue, one can implement polarization diversity scheme to achieve a single polarization on-chip network. One of the essential components in a polarization diversity scheme is the polarization beam splitter (PBS). In this thesis, we will a PBS based on a silicon-on-insulator (SOI) platform with reduced device size and broad operation bandwidth. We use the three-dimensional Finite-Difference Time-Domain (3D-FDTD) method to perform the simulation. First, we use two asymmetric waveguides to design an asymmetric directional coupler with only TE-like mode phase matching condition. We then tape the lower waveguide to keep the TE-polarized light, and split the TE- and TM- polarized light. By utilizing an asymmetrical directional coupler with a tapered waveguide, we have achieved a 7.3

The dissertation focuses on the analysis and design for the new fiber-optic passive components based on the photonic-crystal-fiber (PCF). The vector boundary element method (VBEM) and the finite-difference time-domain (FDTD) method are employed to the propagation characteristics of PCF components. A novel octagonal microstructured fiber (OMF) with eight air-holes in the first ring has been proposed. The OMF has significantly wider wavelength range for single-mode operation, more circular-like field distribution, and less confinement loss. In addition, a novel compact polarization beam splitter (PBS) based on the twin-elliptical-core PCF (TEC-PCF) has also been proposed. It behaves with high extinction ration and broad bandwidth with significantly short splitter length. The design concept and the coupling mechanism are presented in this dissertation based on the normal-mode coupling theory and VBEM.

Ce manuscrit présente deux réalisations d'un double puit magnétique pour des condensats de Bose-Einstein (CBE) sure une puce atomique. Une approche utilise des pièges statiques, crées par des micro fils (en amènent ?) manipulant les atomes proche a la surface de la puce. Comme dans toute manipes, on observe une fragmentation du nuage atomique, quand on approche les atomes vers la structure piégeant. Cet effet était expliqué par une déviation du courant dans le fil à cause d'une rugosité des bords. Pour éviter la fragmentation, une nouvelle technique de fabrication (lithographie a faisceaux a électrons, évaporation d'or) a été utilisé pour créer des fils d'un section de 700nm et une qualité amélioré. Un CBE a été crée et chargé dans le double puit généré par la nano structure. On a testé le double puit comme séparatrice avec des atomes thermiques. Des nombreuses problèmes techniques nous empêchent pour le moment d'effectuer la manip avec un CBE.<br />La deuxième approche poursuit dans cette thèse combine des pièges magnétique statique avec un champ (RF) magnétique alternant et génère un double puit dans le potentiel habillé. Car ce schéma peut être réalisé loin de la surface de la puce, la fragmentation n'apparaisse pas et on a pu séparer un CBE en deux. Une interféromètre d'ondes a matière est réalisé en recombinant les deux nuages en expansion libre. La figure d'interférence permet de mesurer la phase relative, on trouve une distribution étroite de cette phase et donc la séparation est cohérente. L'évolution de la phase relative est mesurée pendant et après la séparation et contrôlé par déséquilibrant le double puit.

Att filma i 3D är en process som kräver mycket kunskap, tid och teknisk utrustning. För att fullständigt behärska detta fält krävs dessutom omfattande praktisk erfarenhet. Denna erfarenhet kan vara svår att få eftersom den ekonomiska investeringen för att filma i 3D ofta är stor. I denna uppsats visar vi att det är möjligt att konstruera en egen 3D-rigg och att filma med vanliga konsumentkameror för att skapa 3D-film. Uppsatsen visar på de begränsningar och svårigheter man stöter på då man bygger sin egen rigg och diskuterar den ekonomiska besparing man kan göra i jämförelse med kommersiella lösningar. Att bygga en egen rigg är tidskrävande och oftast inte att rekommendera i professionella sammanhang. För indieproduktioner, hobby-fotografer eller om man har väldigt specifika krav som ej uppfylls av tillgängliga kommersiella 3D-riggar kan det dock vara motiverat att konstruera sin egen rigg. Kunskapen som uppsatsen redovisar möjliggör ett resonemang för hur bildkvalitet, funktion och ekonomi kan ställas mot varandra i de avvägningar man ställs inför i konstruktionen av en spegelrigg för att filma i 3D.

There has been a huge surge in data traffic all over the world due to the rise of streamingmedia services and connected devices. The current demand in data traffic has alreadypushed the optical fiber in the internet architecture to the network edges and the trend isto push it as close as possible, to the CPU. Silicon photonics addresses this challenge byenabling miniaturized optical devices that use light to move huge amounts of data at veryhigh speeds with extremely low power. To further improve the data transmission capacity,one can make use of different polarizations of light. However, to take advantage ofdifferent polarizations, devices with on-chip polarization rotation capability are required.This is achieved by a tunable polarization rotator. Moreover, full control of polarizationrotation can also be utilized to realize a new class of components in integrated photonicsincluding polarization mode modulators, multiplexers, filters, as well as switches foradvanced optical signal processing, coherent communications, and sensing.This thesis introduces a novel tunable polarization rotator that uses microelectromechanicalsystems (MEMS) as its actuation principle. When voltage is applied to a MEMStunable silicon cantilever, a mechanical movement occurs, which in turn affects theoptical mode shape travelling through a waveguide, as a result of which the polarizationis rotated. In this work, a MEMS tunable polarization rotator is designed, fabricated,and characterized with a polarization extinction ratio of 10 dB, which works in 1530nm -1570nm wavelength spectrum. In addition to the MEMS tunable polarization rotator,in this thesis, a free standing polarization beam splitter of length 1.4 μm, the shortestreported to-date to our knowledge, was designed, fabricated, and characterized. Thetunable polarization rotator and beam splitter developed in this thesis have the potentialto increase the bandwidth and flexibility of current optical communication networks, andfind further applications in polarization diversity schemes for sensing. / Mängden datatrafik i världen har växt explosionsartat de senaste åren på grund av detökade antalet uppkopplade enheter samt det snabbt växande tjänsterna för strömmad media. Det stora databehovet har redan gjort det nödvändigt att använda högkapacitiva optiska länkar hela vägen till nätverkets kanter och trenden är att optisk dataöverföring används närmare och närmare själva CPU:erna i datorerna som utgör källa och slutpunkt för all data på Internet. Kiselfotonik möter denna utmaning genom att möjliggöra miniatyriserade optiska system som använder ljus för att snabbt överföra stora mängder data med liten effektförbrukning. För att öka kapaciteten ännu mer kan man använda sig av ljusets polarisation. För att göra detta måste man tillhandahålla system för att vrida polarisation på chipp-nivå vilket man kan åstadkomma med en avstämbar polarisationsvridare. Utöver en ökad kapacitet kan den nya kontrollen över polarisation även användas för att skapa nya typer av integrerade optiska komponenter som polarisationsbaserade modulatorer, multiplexers, filter, såväl som switchar för optisk signalbehandling, koherent kommunikation och avkänning.Denna avhandling presenterar en ny avstämbar polarisationsvridare som använder en mikroelektromekanisk (MEMS) aktuator. När en spänning är applicerad på en MEMS balk skapas en mekanisk rörelse som i sin tur påverkar den optiska mod-bilden som propagerar i en integrerad optisk vågledare vilket resulterar i att polarisationen vrids. Denna avhandling innehåller design, tillverkning och karakterisering av en avstämbar polarisationsvridare med en polariseringsgrad på 10 dB i våglängdsområdet 1530-1570 nm. Utöver det presenteras design, tillverkning och karakterisering av frihängande polarisationsfördelare med en längd på endast 1.4 µm, den kortaste hittills rapporterad. Dessa komponenter har potentialen att öka bandbredden och flexibilite befintligaoptiska kommunikationsnät och hitta nya tillämpningar i sensorsystem.