La capacité de la tomographie par cohérence optique (OCT) à délivrer des images tomographiques de tissus biologiques in vivo, de manière non invasive et en temps réel, a suscité un intérêt croissant pour de nombreuses applications biomédicales, principalement en ophtalmologie pour l'imagerie de la rétine et du segment antérieur de l'œil. Toutefois, pour l'imagerie à haute résolution de tissus biologiques fortement diffusants, comme la sclérotique et la cornée œdémateuse, la technique nécessitait des améliorations technologiques. Dans cette thèse, un système d'OCT " Fourier-domain " (FD-OCT) à très haute résolution spatiale (< 4 µm), à la longueur d'onde de 1,3 µm, a été développé dans la Laboratoire Charles Fabry - Institute d'Optique Graduate School. Avec ce système original, nous avons réussi, pour la première fois, à visualiser correctement le canal de Schlemm de l'œil humain qui se trouve à une profondeur d'environ 0,8 mm dans le limbe de la cornée, milieu fortement diffusant. L'imagerie du canal de Schlemm est capitale afin d'envisager la chirurgie par laser du glaucome, qui consiste à inciser cette partie de l'œil afin d'améliorer l'écoulement de l'humeur aqueuse. Par ailleurs, en collaboration avec le Laboratoire d'Optique Appliquée de l'ENSTA ParisTech, nous avons démontré la possibilité de contrôler en temps réel par OCT des découpes par laser femtoseconde pratiquées dans la cornée humaine in vitro. Ces travaux ont montré que l'opération du Glaucome par laser femtoseconde, contrôlée par OCT, devrait être possible.

Laser processing has the advantage of minimal sample contact and thus little tool wear over time compared to conventional machining. However, this leads to the difficulty of real-time depth monitoring and control. To help understand the process and achieve automation of laser micromachining, a coherent imaging technique adapted from spectral domain optical coherence tomography (SD-OCT) is applied “inline”with a machining laser to monitor the depth changing information. The axial resolution of the inline coherent imaging (ICI) system is 7–8 microns and the acquisition rate is up to 230 kHz. The capture time is as low as 1.5 microseconds. 3D laser machining usually requires ultrafast lasers and homogeneous materials. With ICI, a feedback system is developed for 3D sculpture suitable even for heterogeneous materials without any sophisticated material characterization. 3D patterns with sizes up to 1 mm × 1 mm × 0.2 mm are sculpted in bone and wood with a ps UV laser. 3D patterns with sizes up to 6 mm × 6 mm × 2 mm are sculpted in bone with a CW IR laser. Many laser applications require high scan speed facilitated by scanning optics. The versatility of ICI is also demonstrated in a galvo-telecentric beam delivery system. ICI is used in a process of trench (as long as 10 mm) etching of steel to monitor the intrapulse and interpulse morphology changes as well as the sweep-to-sweep (up to 36 sweeps) depth changes. High scan speed (up to 375 mm/s) trench etching of silicon are also monitored and the parameter space is explored without destructive post-processing. Motion during imaging capture time (>1.5 microseconds) may cause contrast degradation. To reduce the motion artifacts, preliminary experiments on stroboscopic ICI based on a kHz pulse repetition rate femtosecond laser are described. By “sampling” the motion of the machining front discretely with a “sampling time” as short as the imaging pulse duration, our results demonstrate that stroboscopic ICI is a promising way to improve the ICI contrast against motion artifacts. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2014-04-30 13:56:35.793

Resumo: O fator de transcrição Oct-4 é bem conservado entre as espécies e é conhecido por ser expresso em embriões e células-tronco embrionárias (CTE), sendo um importante marcador da pluripotência. Recentemente, foi relatado que a combinação de Oct-4 com três outros fatores de transcrição Klf-4, c-Myc e Sox2 foram capazes de reprogramar células somáticas a um estado indiferenciado pluripotente, chamadas células-tronco pluripotentes induzidas ("células iPS"), as quais apresentam várias das mesmas propriedades das CTE incluindo a pluripotência, auto-renovação e proliferação. O objetivo desse estudo foi avaliar a funcionalidade do promotor Oct-4 de eqüino em CTE de murinos. Três vetores plasmidiais expressando GFP ("green fluorescent protein") sob o controle do promotor Oct-4 de equinos, camundongo e quatro vetores lentivirais, também contendo o gene reporter GFP e os promotores Oct-4 de equinos, camundongo e humanos, pLZ2-ecOCT-EGFP (meq) (sequência equivalente de camundongos), pLZ2-ecOCT-EGFP (heq) (sequência equivalente de humanos), pLZ2-mOCT-EGFP e pLZ2-hOCT-EGFP, respectivamente, foram construídos. Todos os vetores também contêm um sítio de resistência à blasticidina que permite a seleção das células estáveis e das células transduzidas. Essas construções plasmidiais foram verificadas se funcionavam eficientemente, bem como o efeito do promotor Oct-4 em transfectar transientes e estáveis CTE. As construções com promotor Oct-4 de camundongo, humano e eqüino (sequência análoga à de camundongo) produziram somente 6% de células GFP positivas com intensidade de fluorescência (IF) >1000 pela análise em citômetro de fluxo, enquanto que o plasmídeo contendo o promotor Oct-4 de eqüino (sequência equivalente à de humanos) produziu menos células GFP positivas (>3%) com IF >1000, quando... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The pluripotency transcription factor Oct-4 is well conserved among species and is known to be expressed in embryos and embryonic stem (ES) cells; it is being an important pluripotency marker. It was recently demonstrated that the combination of Oct-4 with three other factors Klf-4, c-myc and Sox2 were able to reprogram somatic cells to a pluripotent and undifferentiated state. These cells known as induced pluripotent stem (iPS) cells share several properties with ES cells including self-renewal, proliferation and pluripotency. The aim of this study was to assess the functionality of the horse Oct-4 promoter in mouse ES cells. Three plasmids vectors expressing GFP (green fluorescent protein) under the control of the horse, mouse and four lentivirus vectors also containing reporter gene GFP and horse, mouse and human promoters, pLZ2-ecOCT-EGFP (mouse sequence equivalent), pLZ2-ecOCT-EGFP (human sequence equivalent), pLZ2-mOCT-EGFP and pLZ2-hOCT-EGFP, respectively, were built. All these vectors also contain a blasticidin resistance cassette to allow selection of transfected stable cells and transduced cells. Afterwards, to assess the functionality of the Oct-4 promoter all plasmids were tranfected the into transient and stable mouse ES cells. Constructs with mouse, human and horse (mouse analog sequence) Oct-4 promoter produced only 6% GFP positive cells with fluorescence intensity (FI)>1000 by 20 FACs assay, while plasmid horse (human analog sequence) Oct-4 promoter produced less GFP positive cells (>3%) with FI>1000, when compared with the positive control and among groups. However, GFP expression was not present in stable cells, whereas there were Blasticidin-resistant colonies-forming from 6 days post-transfection. To optimize the system in mouse ES cells, pLZ2-mOCT-EGFP and pLZ2-hOCT-EGFP lentivectors, were tested as controls. It was used HIV-1-derived... (Complete abstract click electronic access below) / Orientadora: Gisele Zoccal Mingoti / Coorientador: Joaquim Mansano Garcia / Banca: César Roberto Esper / Banca: Flávio Vieira Meirelles / Banca: Áureo Evangelista Santana / Banca: Simone Cristina Méo Niciura / Doutor

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-08T21:11:24Z No. of bitstreams: 1 ArianoBritoDeFarias_DISSERT.pdf: 1699559 bytes, checksum: 34e87398edd5ddd9e4071c66e736ef1a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-12T20:56:12Z (GMT) No. of bitstreams: 1 ArianoBritoDeFarias_DISSERT.pdf: 1699559 bytes, checksum: 34e87398edd5ddd9e4071c66e736ef1a (MD5) / Made available in DSpace on 2016-07-12T20:56:12Z (GMT). No. of bitstreams: 1 ArianoBritoDeFarias_DISSERT.pdf: 1699559 bytes, checksum: 34e87398edd5ddd9e4071c66e736ef1a (MD5) Previous issue date: 2015-09-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Na ind?stria do petr?leo, o g?s natural ? um componente vital no suprimento de energia do mundo e uma importante fonte de muitos hidrocarbonetos. ? uma das mais limpas, mais segura e mais aplic?vel de todas as fontes de energia, e ajuda a conhecer a crescente demanda mundial por energia limpa no futuro. Com a crescente participa??o do g?s natural na matriz energ?tica no Brasil, o principal objetivo de seu uso tem sido o abastecimento de energia el?trica atrav?s da gera??o de energia t?rmica. No processo de produ??o atual, como em uma Unidade de Processamento de G?s Natural (UPGN), o g?s natural passa por diversas unidades de separa??o visando ? produ??o de g?s natural liquefeito e g?s combust?vel. Este ?ltimo deve ser especificado para atender as m?quinas t?rmicas. No caso dos po?os remotos, o processo de absor??o dos componentes pesados visando o seu ajuste ? uma alternativa para de aumentar a malha energ?tica do pa?s e/ou local. Atualmente, devido ? elevada demanda por este g?s processado, a pesquisa e o desenvolvimento de t?cnicas que visam o ajuste do g?s natural s?o estudados. M?todos convencionais hoje empregados, como a absor??o f?sica, possuem bons resultados. O objetivo do trabalho ? avaliar a remo??o dos componentes pesados do g?s natural. Nesta pesquisa foi utilizado como absorvente f?sico o ?lcool oct?lico. Foi estudada a influ?ncia dos par?metros, como temperatura (5?C e 40?C) e vaz?o (25 e 50 ml/min) sobre o processo de absor??o em termos de capacidade de absor??o, expresso pela quantidade absorvida; e em termos cin?ticos, expresso pelo coeficiente de transfer?ncia de massa. Conforme esperado pela literatura, foi observado que a absor??o das fra??es pesadas de hidrocarbonetos ? favorecida em baixas temperaturas. Por outro lado, tanto a temperatura como a vaz?o favorece a transfer?ncia de massa, efeito cin?tico. A cin?tica de absor??o de remo??o dos componentes pesados foi acompanhada atrav?s de an?lise cromatogr?fica e os resultados experimentais mostraram elevado percentual de recupera??o dos componentes pesados. Al?m disso, foi observado que o emprego de ?lcool oct?lico como agente absorvedor demonstrou ser vi?vel o processo de separa??o. / In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 ?C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.

Abstract Doppler optical coherence tomography (DOCT) provides a non-disruptive, high resolution and real-time method for imaging flow velocity profiles inside small channels and capillaries. DOCT has been mostly used in the biomedical field to image blood flow. However, applications in the field of rheology have been rare. In this thesis, the time domain DOCT (TD-DOCT) was utilized to measure flow velocity profiles inside capillaries with high resolution. Time domain configuration was chosen due to the ability to implement dynamic focusing and, in addition, to have sufficient velocity range, especially at high speeds. The accuracy and reliability of the laboratory-built DOCT device was verified with Newtonian suspension and, further, the performance was compared to the commercial DOCT. In vivo measurements with slime mould Physarum polycephalum showed the versatility of DOCT to measure the flow velocity profile of a different kind of scattering suspension even with very low flow rates. The effects of multiple scattering on the accuracy of the measured flow velocity profiles were experimentally studied with two phantom configurations. The first case consisted of the static superficial layer, where the plain glass capillary with flowing Intralipid suspension was embedded into a cuvette. In the second case the moving superficial layer was made by introducing a second glass capillary in front of the studied flow. The results showed that multiple scattering has noticeable effect on the accuracy of the measured flow velocity profiles, especially at the deeper regions. Novel application of the DOCT technique is presented by implementing it to a capillary viscometer. As a result, the absolute viscosity of the Newtonian suspension is derived with high precision directly from the measured flow velocity profile and pressure drop without making any assumption of the flow under study. The results are consistent with the reference values measured with the commercial viscometer. / Tiivistelmä Doppler optinen koherenssitomografia (DOCT) on tekniikka, jolla on mahdollista mitata suspensioiden virtausnopeusprofiili virtausta häiritsemättömästi, reaaliaikaisesti ja tarkalla resoluutiolla ohuista kapillaareista. DOCT-tekniikkaa on hyödynnetty erityisesti lääketieteen alueella silmän rakenteen kuvantamisessa ja veren virtausmittauksissa. Tekniikan sovellukset nesteiden reologian tutkimuksessa ovat olleet harvinaisia. Tämän työn tarkoituksena on kehittää DOCT-tekniikkaa ja soveltaa sitä kapillaariviskometrissä viskositeetin määritykseen suoraan mitatusta virtausnopeusprofiilista. Tässä työssä hyödynnettiin laboratoriossa rakennettua aikatason DOCT-laitetta (TD-DOCT), jolla mitattiin virtausnopeusprofiili kapillaarin sisältä mikrometrien resoluutiolla. TD-DOCT valittiin, koska siinä voitiin käyttää dynaamista fokusointia parantamaan sivusuuntaista resoluutiota ja signaali-kohinasuhdetta. Tämän lisäksi se soveltuu laaja-alaisesti eri virtausnopeuksille, erityisesti nopeille virtauksille. Rakennetun DOCT-laitteen tarkkuus ja luotettavuus todennettiin mittaamalla Newtonista suspensiota ja vertaamalla mittaustuloksia kaupallisella DOCT:lla tehtyihin mittauksiin. Mittaukset elävässä organismissa, Physarum polycephalum -limasienessä, osoittavat laitteen soveltuvuuden erilaisten suspensioiden virtausnopeusprofiilin mittaukseen myös hyvin hitaissa virtauksissa. Moninkertaisen sironnan vaikutusta mitattujen profiilien tarkkuuteen tutkittiin kahdella eri konfiguraatiolla. Ensimmäisessä asetelmassa virtausnopeusprofiili mitattiin kapillaarista, joka oli upotettu valoa sirottavaan Intralipid-suspensioon, ja jonka upotussyvyyttä voitiin säätää. Toisessa asetelmassa muodostettiin dynaaminen valoa sirottava kerros asettamalla toinen Intralipidiä sisältävä kapillaari mitattavan kapillaarin eteen. Tulokset osoittavat, että monikertainen sironta vaikuttaa mitatun virtausnopeusprofiilin tarkkuuteen erityisesti kun valoa sirottava kerroksen paksuus kasvaa. Tässä työssä DOCT -tekniikkaa käytetään ensimmäistä kertaa kapillaariviskometrin yhteydessä. Newtonisen suspension absoluuttinen viskositeetti määritetään hyvin tarkasti suoraan mitatusta virtausnopeusprofiilista ja painehäviöstä ilman oletuksia virtaavasta nesteestä. Mitatut viskositeettiarvot vastaavat vertailumittauksia, jotka tehtiin kaupallisella rotaatioviskosimetrilla.

Abstract Light scattering diagnostics of turbid media containing both structural and dynamic inhomogeneities is currently of significant importance. One of the important directions in modern light scattering diagnostics is the development of methods for probing biological media with visible- and near-infrared radiation allowing for visualization of the biotissue structure. Optical methods for studying the biotissue structure and characterization of its optical properties are very promising and have been rapidly developing during the past decade. The present work is aimed at improving and discovering new potentials of currently existing methods of laser diagnostics of biological tissues containing both structural and dynamic inhomogeneities. In particular, the feasibilities of spatially resolved reflectometry and time-of-flight techniques for the problem of noninvasive determination of glucose level in human blood and tissues were examined both numerically and experimentally. The relative sensitivities of these methods to changes in glucose level were estimated. Time-of-flight technique was found to be more sensitive. The possibilities of Doppler optical coherence tomography for imaging of dynamic inhomogeneities with high resolution were considered. This technique was applied for the first time for the imaging of complex autowave cellular motility and cytoplasm shuttle flow in the slime mold Physarum polycephalum. The effect of multiple scattering on the accuracy of the measured flow velocity profiles for the case of single flow and for the case of the flow embedded into the static medium with strong scattering was studied. It was shown that this effect causes significant distortion to the measured flow velocity profiles and it is necessary to take this into account while making quantitative measurements of flow velocities.

This work describes optical coherence tomography, it's principle and methods for automatic segmentation intra-retinal layers in OCT images . There is proposed algorithm for boundary detection of two intra retinal layers, RFNL and RPE layer based on thresholding and second algorithm for detection of seven layers, which is based on graph search algorithm. In summary is compared accuracy against manualy segmented layers and there is also proposed solution for problematic parts.

In der vorliegenden Arbeit wurde die Netzhaut einiger tagaktiver Raubvögel hinsichtlich ihrer morphologischen und morphometrischen Eigenschaften mit verschiedenen Methoden untersucht. Über die Histologie werden Gestalt und Subspezialisierungen der Netzhaut von neun Vögel sieben verschiedener Spezies in ihrer nasal-temporalen und superior-inferioren Ausdehnung betrachtet. Besonderes Augenmerk lag hierbei auf dem Verhältnis der Photorezeptor- und Neuronenpopulationen zueinander, da hier über den Grad von Konvergenz oder Divergenz der Verschaltung Informationen über die intraretinale Signalverarbeitung gewonnen werden können. Über das Verfahren der Immunhistochemie wurde zudem untersucht, ob sich die Spezies hinsichtlich der intraretinalen Verteilung einiger ausgewählter Marker von Strukturen der Müllerzellen und der Photorezeptoren unterscheiden. Eine weitere angewandte Methode war die optische Kohärenztomographie, ein bildgebendes Verfahren, das non-invasiv in vivo Schnittbilder der Netzhaut erzeugt. Hier konnte gezeigt werden, dass diese aus der humanen Augenheilkunde bekannte Untersuchungstechnik auch am aviären Patienten anwendbar ist. Desweiteren wurde die Darstellbarkeit der aviären Netzhaut, ihrer Besonderheiten und pathologischer Veränderungen bei den verschiedenen Raubvogelspezies untersucht. Für bestimmte Regionen in der Raubvogelnetzhaut wie die Fovea centralis und temporalis, sind in historischen Untersuchungen Formunterschiede beschrieben worden und es konnte gezeigt werden, dass diese auch in vivo bestehen. Zuletzt wird die Frage behandelt, welche Unterschiede der Vergleich zwischen den beiden Verfahren der Netzhautdarstellung aufdeckt, inwiefern beide fehlerbehaftet sind und was bei der Interpretation beachtet werden sollte.:Inhaltsverzeichnis 1 Einleitung 1 1.1 Grundlagen zur Netzhaut 1 1.2 Die optische Kohärenztomographie (OCT) 6 1.3 Aufgabenstellung und klinische Relevanz 7 2 Material und Methoden 10 2.1 Untersuchungsmaterial 10 2.2 Spezies der histomorphologischen Untersuchung 10 2.3 Histologie und Immunhistochemie 14 2.4 Vergleich von OCT-Abbildung und histologischem Korrelat 25 2.5 Untersuchung der Ultrastruktur der aviären Netzhaut 28 3 Ergebnisse 30 3.1 Histologische und immunhistochemische Analyse der Netzhaut von tagaktiven Raubvogelspezies 30 3.2 Untersuchung retinaler Strukturen bei tagaktiven Raubvögeln mittels OCT 84 3.3 Vergleich der Darstellung in OCT und Histologie 91 3.4 Elektronenmikroskopie der äußeren Netzhaut des Raubvogels 95 4 Diskussion 98 4.1 Morphometrische Untersuchungen in Histologie und Immunhistochemie 98 4.2 OCT-Untersuchung von tagaktiven Raubvögeln 110 4.3 Verhältnis von OCT und histologischem Abbild 113 4.4 Fazit und Ausblick 115 Zusammenfassung 117 Literatur 121 Anhang

Today, medical imaging is playing an important role in medicine as it provides the techniques and processes used to create images of the human body or parts thereof for clinical purposes (medical procedures seeking to reveal, diagnose or examine disease) or medical science (including the study of normal anatomy and function). Modalities are developing over time to achieve the highest possible resolution, speed of image acquisition, sensitivity, and specificity. In the past decade, advances in optics, fiber, as well as laser technology have enabled the development of noninvasive optical biomedical imaging technology that can also be applied to endoscopy to reach deeper locations in the human body. The purpose of this dissertation is to investigate a full system design and optimization of an optical coherence tomography (OCT) system to achieve high axial and lateral resolution together with an extended depth of focus for endoscopic in vivo imaging. In this research aimed at advancing endoscopic OCT imaging, two high axial resolution optical coherence tomography systems were developed: (1) a spectrometer-based frequency-domain (FD) OCT achieving an axial resolution of ~2.5 µm using a Ti:Sa femtosecond laser with a 120nm bandwidth centered at 800nm and (2) a swept-source based FD OCT employing a high speed Fourier domain mode locked (FDML) laser that achieves real time in vivo imaging with ~8 µm axial resolution at an acquisition speed of 90,000 A-scans/sec. A critical prior limitation of FD OCT systems is the presence of mirror images in the image reconstruction algorithm that could only be eliminated at the expense of depth and speed of imaging. A key contribution of this research is the development of a novel FD OCT imager that enables full range depth imaging without a loss in acquisition speed. Furthermore, towards the need for better axial resolution, we developed a mathematical model of the OCT signal that includes the effect on phase modulation of phase delay, group delay, and dispersion. From the mathematical model we saw that a Fourier domain optical delay line (FD ODL) incorporated into the reference arm of the OCT system represented a path to higher performance. Here we then present a method to compensate for overall system dispersion with a FDODL that maintains the axial resolution at the limit determined solely by the coherence length of a broadband source. In the development of OCT for endoscopic applications, the need for long depth of focus imaging is critical to accommodate the placement of the catheter anywhere within a vessel. A potential solution to this challenge is Bessel-beam imaging. In a first step, a Bessel-beam based confocal scanning optical microscopy (BCSOM) using an axicon and single mode fiber was investigated with a mathematical model and simulation. The BCSOM approach was then implemented in a FD OCT system that delivered high lateral resolution over a long depth of focus. We reported on the imaging in biological samples for the first time with a double-pass microoptics axicon that demonstrated clearly invariant SNR and 8 um lateral resolution images across a 4 mm depth of focus. Finally, we describe the design and fabrication of a catheter incorporated in the FD OCT. The design, conceived for a 5 mm outer diameter catheter, allows 360 degree scanning with a lateral resolution of about 5 um across a depth of focus of about 1.6 mm. The dissertation concludes with comments for related future work.

The short-term jitter and longer-term wander of the frequency sweep profile of a Vernier-Tuned Distributed Bragg Reflector (VT-DBR) laser at 1550 nm used in optical coherence tomography (OCT) and other sensing applications is characterized in this work. The VT-DBR has demonstrated success in source-swept OCT (SSOCT), performing both intensity and phase-sensitive OCT. The purpose of this paper is to investigate one of the unique aspects of the VT-DBR laser that makes it successful in OCT: the stability of the linear optical frequency sweep. A highly stable linear optical frequency sweep implies benefits for further fiber sensing applications including fiber Bragg grating and spectroscopy sensors. Short-term jitter measurements of the optical frequency sweep are taken using a 3-cavity 100 GHz free spectral range solid etalon, an athermal fiber Bragg grating, a molecular-based gas absorption reference cell, and a Mach-Zehnder interferometer. These four optical filters are used to convert time fluctuations into intensity fluctuations that can be measured by high speed optical receivers. Short term jitter values on the order of 0.5 – 0.6 pm RMS (63 – 82 MHz RMS) are typical values in the VT-DBR lasers systems characterized in this work. This level of jitter is compelling for OCT and fiber-sensing applications. Longer-term wander is characterized using a multiple-gas absorption reference cell. The long term stability and temperature insensitivity of the absorption cell is ideal for long-term wander characterization of the laser frequency sweeps. Wander values on the order of 2.6 pm of wavelength shift over an 8 hour time frame are reported in this work. The slope of the frequency versus time function of the laser sweep, on the order of 100 MHz/sample, is found to deviate by no more than 0.03% over the same 8 hour time frame. Both the long term wavelength shift and consistency of the slope indicate that these sources will perform well in OCT and fiber sensing applications. Mechanisms responsible for short-term jitter and longer- term wavelength wander likely include contributions from the laser source itself and from the high speed electronic drive circuitry that creates the wavelength ramp. Investigation of ambient temperature’s influence on the wavelength wander is also highlighted in the work.