International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / The requirement for improved ramp telemetry data and video coverage has prompted the Telemetry Branch at the Naval Air Warfare Center Aircraft Division (NAWCAD) to install an L and S-Band Fiberoptic Transmission System linking multiple hangar locations to the Telemetry Data Center. This system uses Commercial-off-the-Shelf (COTS) equipment and is capable of transmitting analog telemetry data and video from multiple sites to one location for processing and display. The system at NAWCAD has been in use since 1996 and is continually growing to accommodate additional requirements.

Prostate cancer is one of the leading causes of death by cancer for men. Focal therapy is being tested to target only the dominant cancer lesion in the prostate. However, due to the need to ensure that the laser is targeting only the cancer, a real-time treatment monitoring system is required. A combined optical-ultrasound monitoring system is in development at Princess Margaret Hospital based on different optical properties for coagulated versus normal tissue. In this project, we developed a light delivery and collection device that is compatible for use with an existing trans-rectal ultrasound-imaging probe. Computer-aided design software was used to visualize the prototype in relation to the trans-rectal ultrasound probe. This thesis describes the critical tasks necessary to assemble the final prototype, including listing of specifications, selection of device material based on safety and mechanical properties, method of prototype fabrication, positioning and fixation of optical fibers and testing.

Prostate cancer is one of the leading causes of death by cancer for men. Focal therapy is being tested to target only the dominant cancer lesion in the prostate. However, due to the need to ensure that the laser is targeting only the cancer, a real-time treatment monitoring system is required. A combined optical-ultrasound monitoring system is in development at Princess Margaret Hospital based on different optical properties for coagulated versus normal tissue. In this project, we developed a light delivery and collection device that is compatible for use with an existing trans-rectal ultrasound-imaging probe. Computer-aided design software was used to visualize the prototype in relation to the trans-rectal ultrasound probe. This thesis describes the critical tasks necessary to assemble the final prototype, including listing of specifications, selection of device material based on safety and mechanical properties, method of prototype fabrication, positioning and fixation of optical fibers and testing.

The development of reliable, affordable, and efficient sensors is a key step forward in providing tools for efficient monitoring of critical environmental parameters. Fiber-optic sensors are already widely used in various industrial sensing fields. They have proven themselves reliable in harsh environments and can measure different physical quantities, such as temperature, pressure, strain, refractive index (RI), and humidity. Fiber-optic Mach-Zehnder Interferometer (MZI) is a well-studied optical fiber interferometer that has proven capacity for sensing ambient refractive index. In this dissertation, we present Fiber Bragg grating (FBG) embedded in a microfiber Mach-Zehnder Interferometer designed for sensing temperature and refractive index. The MZI is constructed by splicing a short length of 40-μm-diameter microfiber between standard single mode fibers. A one-millimeter-long FBG is then written in the microfiber using a direct, point-by-point, ultrafast laser inscription method. The microfiber MZI shows only moderate sensitivity to ambient refractive index and temperature changes. In contrast, the microfiber FBG is insensitive to ambient refractive index change, while it exhibits typical sensitivity to temperature variation. These distinct characteristics of the FBG and MZI sensors enable the simultaneous measurement of refractive index and temperature as well as temperature compensation in ambient refractive index measurement. Further, we report the use of a fiber-optic Mach-Zehnder Interferometer to measure core refractive index changes written by femtosecond laser irradiation. The core-offset interferometer was constructed by splicing a lightly misaligned stub of standard single-mode fiber between the device’s lead-in and lead-out optical fibers. When the core refractive index of an in-fiber interferometer is altered, that process changes the phase of the core light. Since the phase of light propagating in the cladding (reference arm) remains unchanged, the transmission fringe pattern of the interferometer undergoes a spectral shift. In the present research, that spectral shift was used to quantify the effective core refractive index change in a standard single-mode fiber. In addition, we designed and developed a custom flame-based tapering machine that is used to fabricate miniaturized Mach–Zehnder interferometers (MZIs) using sharply tapered photonic crystal fiber (PCF). This technique produces sensors capable of highly sensitive ambient refractive index (RI) measurements. The sensor is fabricated by fusion splicing a small stub of PCF between standard single-mode fibers with fully collapsed air holes of the PCF in a splicing region. Tiny flame geometry enables the sharp tapering of the PCF, resulting in a short fiber length and high RI sensitivity. It appears that sharp tapering has a great impact on RI sensitivity enhancement, when compared with methods that decrease taper waist diameter. The tapering technique is further used to construct the Mach-Zehnder Interferometer-based fiber-optic refractive index (RI) sensor by uniformly tapering standard single mode fibers (SMF) for RI measurement. The fabricated MZI device does not require any splicing of fibers and shows excellent RI sensitivity. / Graduate

This dissertation describes the development of the fiberoptic microneedle device (FMD), a microneedle technology platform for fluid and light delivery, from general engineering characterization to specific applications in treating bladder and brain cancers. The central concept of the FMD is physical modification of silica fiberoptics and capillary tubes into sharp microneedles capable of penetrating a tissue's surface, enabling light and fluid delivery into the interstitial spaces. Initial studies sought to characterize the mechanical penetration and optical delivery of multimode fiberoptics and capillary tubes modified through a custom, CO2 laser melt-drawing technique. Additional work with multimode fibers investigated using an elastomeric lateral support medium to ensure robust penetration of small diameter fibers. These early experiments laid an engineering foundation for understanding the FMD technology. Subsequent studies focused on developing the FMD to treat specific diseases. The first such investigation sought to leverage the high aspect ratio nature of FMDs made from long capillary tubes as a therapy delivery device deployable through the instrument channel of a urological cystoscope. The therapeutic strategy was to infuse single-walled carbon nanohorns (SWNHs), a carbon-based nanoparticle allowing surface modification and drug encapsulation, into the infiltrating front of later stage bladder tumors. The SWNHs primarily serve as exogenous chromophores, enabling a fluid-based control of photothermal heat generation created when the SWNHs interacted with laser energy from an interstitial FMD or a light-emitting fiber in the bladder's interior. The study described here primarily sought to characterize the dispersal of the infused SWNHs and the photothermal response of the particles when heated with a 1064 nm laser. The FMD was also developed as a platform capable of conducting convection-enhanced delivery (CED), a therapeutic approach to treat invasive tumors of the central nervous system such as malignant glioma (MG). Intracranial CED involves the placement of small catheters local to the tumor site and slow infusion of a chemotherapeutic over long timeframes (12-72 hours). A primary challenge of this treatment approach is infused chemotherapeutics not dispersing sufficiently to reach the infiltrating cells in the tumor's margins. The hypothetical improvement provided by the FMD technology is using sub-lethal photothermal heating to sufficiently increase the diffusive and convective transport of an infusate to reach infiltrative cells in the tumor's periphery. Initial experiments sought to demonstrate and characterize a heat-mediated increase of volumetric dispersal in Agarose tissue phantoms and ex vivo tissue. Subsequent studies with in vivo rodent models determined the best laser parameters to achieve the desired levels of diffuse, sub-lethal heat generation and then demonstrated the hypothesis of increasing the rate of volumetric dispersal though concurrent local hyperthermia. This research was the first demonstration of photothermal augmentation of an interstitially infused fluid's dispersal rate, which may have uses outside of the CED approach to brain cancer exhibited here. Taken in sum, this manuscript describes the potency and versatility of the FMD technology platform through its development in various biomedical applications. / Ph. D.

Die chromatische Dispersion ist in optischen Übertragungssystemen mit Datenraten von 10 Gbit/s und darüber einer der Faktoren, der die Länge der Übertragungsstrecke limitiert. Der Hauptteil der chromatischen Dispersion wird in solchen Übertragungssystemen in der Regel durch Dispersionskompensationsfasern ausgeglichen. Aufgrund von z.B. Umwelteinflüssen kann allerdings auch eine sich zeitlich ändernde Dispersion auftreten. Zur Eliminierung dieser Restdispersion wurden unterschiedliche Ansätze wie abstimmbare Faser-Bragg-Gitter, Virtually-Imaged-Phased-Arrays und Delay-Line-Filter publiziert. Delay-Line-Filter, deren periodisches Übertragungsverhalten durch die Filterkoeffizienten bestimmt wird, wurden bereits als Ring-Resonatoren und kaskadierte Mach-Zehnder-Interferometer in integriert-optischer Technologie hergestellt. Integriert-optische Komponenten verursachen aufgrund der Ankopplung an die Fasern des Übertragungssystems hohe Einfügeverluste. Darüber hinaus treten hohe Wellenleiterverluste, polarisationsabhängige Verluste und Polarisationsmodendispersion auf. Daher wird in dieser Arbeit die Realisierung faseroptischer Delay-Line-Filter, die auf faseroptischen Schmelzkopplern und faseroptischen Gewichtungselementen basieren, untersucht. Aufgrund der geometrischen Längen der faseroptischen Schmelzkoppler und der Größe der Gewichtungselemente können solche Filter allerdings nur mit einer geringen Filterordnung und mit einer geringen Anzahl von Gewichtungselementen hergestellt werden. Um mit Filtern niedriger Ordnung eine möglichst effektive Kompensation der Restdispersion zu erzielen, ist zunächst eine sorgfältige Untersuchung der Filtereigenschaften und des Filterentwurfs erforderlich. Durch systematische Untersuchung des Verhaltens der Filterdispersion in Abhängigkeit der Filterkoeffizienten wurden in dieser Arbeit hierzu erstmalig einfache Entwurfsregeln aufgestellt, die für Filter beliebiger Filterordnung zu annähernd konstantem Dispersionsverlauf führen. Auf dieser Grundlage konnte ein faseroptisches Delay-Line-Filter realisiert werden, das auf zwei in Reihe geschalteten faseroptischen 3x3 Schmelzkopplern basiert. Die Dispersion dieses Filters ist in einem Bereich von 50 GHz um die Mitte einer Filterperiode herum annähernd konstant und kann in einem Bereich von +/-50 ps/nm durch ein einzelnes thermisches Gewichtungselement abgestimmt werden. Aufgrund der faseroptischen Realisierung kann die Komponente problemlos in optische Übertragungsstrecken integriert werden und verursacht dabei Einfügeverluste von lediglich 3 dB. In Übertragungsexperimenten bei Datenraten von 42,5 Gbit/s konnte gezeigt werden, dass das Filter in der Lage ist die Dispersionstoleranz des Systems annähernd zu verdoppeln. Dies gilt sowohl für die Kompensation eines einzelnen Kanals als auch für die simultane Kompensation mehrerer benachbarter Übertragungskanäle mit je 42,5 Gbit/s. / Chromatic dispersion is a limiting factor in fast optical networks with channel bit rates of 10 Gbit/s or higher. The main part of the dispersion is usually compensated by spans of dispersion compensating fiber that have a fixed dispersion value. But the residual dispersion caused by environmental changes or rerouting has to be compensated adaptively. To overcome the effects of residual dispersion several approaches like tunable fiber Bragg gratings, virtually imaged phased arrays and delay line filters can be found in literature. The use of delay line filters like cascaded ring-resonators, multi-cavity etalons and cascaded Mach-Zehnder interferometers, whose periodic transfer behavior is determined by their coefficients, have already been developed in planar-optics. These components cause insertion loss due to the coupling to the fibers. Furthermore they suffer from high waveguide loss, non-negligible polarization dependent loss and polarization mode dispersion. In this thesis the realization of tunable delay line filters based on fiberoptic couplers and fiberoptic weighting elements is investigated. Due to the size of these components the filters can be realized with a limited order and a limited number of weighting elements, only. To fulfill these requirements a careful investigation of the filter design is necessary. By systematically investigating the dispersion of the filter depending on the filter coefficients simple design rules for non-recursive delay line filters with approximately constant dispersion are figured out. That enables the realization of a fiberoptic delay line filter, based on two 3x3 couplers concatenated in series. The dispersion of this filter is constant in a bandwidth of about 50 GHz around the center of a period and can be tuned in a range of +/-50 ps/nm by changing one single weighting element. Due to its nature this device causes low loss and can be easily integrated in an optical transmission system. In experiments it was demonstrated that by adding this filter to a 42.5 Gb/s transmission system the +/- 55 ps/nm dispersion tolerance of the optical receiver can almost be doubled - either in a single channel as well as in a multi channel configuration with five adjacent 42.5 Gb/s channels.

Die chromatische Dispersion ist in optischen Übertragungssystemen mit Datenraten von 10 Gbit/s und darüber einer der Faktoren, der die Länge der Übertragungsstrecke limitiert. Der Hauptteil der chromatischen Dispersion wird in solchen Übertragungssystemen in der Regel durch Dispersionskompensationsfasern ausgeglichen. Aufgrund von z.B. Umwelteinflüssen kann allerdings auch eine sich zeitlich ändernde Dispersion auftreten. Zur Eliminierung dieser Restdispersion wurden unterschiedliche Ansätze wie abstimmbare Faser-Bragg-Gitter, Virtually-Imaged-Phased-Arrays und Delay-Line-Filter publiziert. Delay-Line-Filter, deren periodisches Übertragungsverhalten durch die Filterkoeffizienten bestimmt wird, wurden bereits als Ring-Resonatoren und kaskadierte Mach-Zehnder-Interferometer in integriert-optischer Technologie hergestellt. Integriert-optische Komponenten verursachen aufgrund der Ankopplung an die Fasern des Übertragungssystems hohe Einfügeverluste. Darüber hinaus treten hohe Wellenleiterverluste, polarisationsabhängige Verluste und Polarisationsmodendispersion auf. Daher wird in dieser Arbeit die Realisierung faseroptischer Delay-Line-Filter, die auf faseroptischen Schmelzkopplern und faseroptischen Gewichtungselementen basieren, untersucht. Aufgrund der geometrischen Längen der faseroptischen Schmelzkoppler und der Größe der Gewichtungselemente können solche Filter allerdings nur mit einer geringen Filterordnung und mit einer geringen Anzahl von Gewichtungselementen hergestellt werden. Um mit Filtern niedriger Ordnung eine möglichst effektive Kompensation der Restdispersion zu erzielen, ist zunächst eine sorgfältige Untersuchung der Filtereigenschaften und des Filterentwurfs erforderlich. Durch systematische Untersuchung des Verhaltens der Filterdispersion in Abhängigkeit der Filterkoeffizienten wurden in dieser Arbeit hierzu erstmalig einfache Entwurfsregeln aufgestellt, die für Filter beliebiger Filterordnung zu annähernd konstantem Dispersionsverlauf führen. Auf dieser Grundlage konnte ein faseroptisches Delay-Line-Filter realisiert werden, das auf zwei in Reihe geschalteten faseroptischen 3x3 Schmelzkopplern basiert. Die Dispersion dieses Filters ist in einem Bereich von 50 GHz um die Mitte einer Filterperiode herum annähernd konstant und kann in einem Bereich von +/-50 ps/nm durch ein einzelnes thermisches Gewichtungselement abgestimmt werden. Aufgrund der faseroptischen Realisierung kann die Komponente problemlos in optische Übertragungsstrecken integriert werden und verursacht dabei Einfügeverluste von lediglich 3 dB. In Übertragungsexperimenten bei Datenraten von 42,5 Gbit/s konnte gezeigt werden, dass das Filter in der Lage ist die Dispersionstoleranz des Systems annähernd zu verdoppeln. Dies gilt sowohl für die Kompensation eines einzelnen Kanals als auch für die simultane Kompensation mehrerer benachbarter Übertragungskanäle mit je 42,5 Gbit/s. / Chromatic dispersion is a limiting factor in fast optical networks with channel bit rates of 10 Gbit/s or higher. The main part of the dispersion is usually compensated by spans of dispersion compensating fiber that have a fixed dispersion value. But the residual dispersion caused by environmental changes or rerouting has to be compensated adaptively. To overcome the effects of residual dispersion several approaches like tunable fiber Bragg gratings, virtually imaged phased arrays and delay line filters can be found in literature. The use of delay line filters like cascaded ring-resonators, multi-cavity etalons and cascaded Mach-Zehnder interferometers, whose periodic transfer behavior is determined by their coefficients, have already been developed in planar-optics. These components cause insertion loss due to the coupling to the fibers. Furthermore they suffer from high waveguide loss, non-negligible polarization dependent loss and polarization mode dispersion. In this thesis the realization of tunable delay line filters based on fiberoptic couplers and fiberoptic weighting elements is investigated. Due to the size of these components the filters can be realized with a limited order and a limited number of weighting elements, only. To fulfill these requirements a careful investigation of the filter design is necessary. By systematically investigating the dispersion of the filter depending on the filter coefficients simple design rules for non-recursive delay line filters with approximately constant dispersion are figured out. That enables the realization of a fiberoptic delay line filter, based on two 3x3 couplers concatenated in series. The dispersion of this filter is constant in a bandwidth of about 50 GHz around the center of a period and can be tuned in a range of +/-50 ps/nm by changing one single weighting element. Due to its nature this device causes low loss and can be easily integrated in an optical transmission system. In experiments it was demonstrated that by adding this filter to a 42.5 Gb/s transmission system the +/- 55 ps/nm dispersion tolerance of the optical receiver can almost be doubled - either in a single channel as well as in a multi channel configuration with five adjacent 42.5 Gb/s channels.

Objective: In patients with Parkinson’s disease (PD), deep brainstimulation of the subthalamic nucleus (STN DBS) is well recognizedin improving limb function, but the outcome on swallowing functionhas rarely been studied. The aim of this work was to evaluate theeffect of STN DBS on pharyngeal swallowing function in patientswith PD using self-estimation and fiberoptic endoscopic evaluation ofswallowing. Methods: Eleven patients (aged 41–72, median 61 years)were evaluated preoperatively and at 6 and 12 months after STN DBSsurgery. All patients were evaluated with self-estimation on a visualanalogue scale, and eight of them with a fiberoptic endoscopicexamination with a predefined swallowing protocol includingRosenbek’s Penetration-Aspiration Scale, Secretion Severity Scale,preswallow spillage, pharyngeal residue, and pharyngeal clearance. Results: The self-assessments of swallowing function revealed asubjective improvement with STN DBS stimulation, whereas the datafrom the swallowing protocol did not show any significant effect ofthe STN DBS treatment itself. The prevalence of aspiration was notaffected by the surgery. Conclusions: The results show thatswallowing function was not negatively affected by STN DBS and therisk of aspiration did not increase. Self-estimation of swallowingfunction showed a subjective improvement due to stimulation / Speech, voice and swallowing outcomes after deep brain stimulation (DBS)

The diagnostic accuracy attained with the use of transbronchial fine needle aspiration biopsy, aspiration of bronchial secretion, bronchial washing, brush biopsy and forceps biopsy via a flexible fiberoptic bronchoscope was compared in patients with carcinoma of the lung. In endoscopic visible tumours the sensitivity of forceps biopsy was higher than that of the other methods. When forceps biopsy was combined with bronchial washing the overall diagnostic accuracy was significantly higher than that of any of the single methods, while no appreciable increase was obtained by adding additional methods. Selective brush biopsy from every segment bronchus has been established as a method in the search for occult bronchial carcinoma. The extent of respiratory mucosal damage and wound healing after brush biopsy was therefore studied in rabbits. Large differences in the extension and depth of the damage was observed. The basement membrane was often penetrated. Regeneration started during the first day after brush biopsy and a normal ciliated epithelium was restored within three weeks. To determine if the bronchoscope itself damaged the respiratory epithelium, bronchial mucosa was studied in the pig after examination with a flexible fiberoptic bronchoscope. The columnar epithelial cells were torn off in areas where the bronchoscope had rubbed against the airway wall but the basement membrane was not damaged. Since the function of the respiratory epithelium is to remove inhaled particles from the airways, mucociliary clearance was studied in man after fiberoptic bronchoscopy. The study suggests that the tracheobronchial clearance system has a large reserve for mechanical trauma. Mucociliary clearance can however be decreased after fiberoptic bronchoscopy in some patients. An increasing number of patients with impaired cardiopulmonary function are today subjected to examination with flexible fiberoptic broncoscopy. The haemodynamic effects of fiberoptic bronchoscopy performed under topical anaesthesia were therefore studied in patients with restrictive lung disease. The procedure induced marked haemodynamic changes during passage of the larynx and during suctioning. A slight fall in arterial oxygen tension was observed during bronchial suctioning and in the post-bronchoscopic period. Three of ten patients developed ST-T-segment changes during bronchial suctioning. / <p>S. 1-48: sammanfattning, s. 49-126: 5 uppsatser</p> / digitalisering@umu.se