Birefringence offers an intrinsic contrast mechanism related to the microstructure and arrangement of fibrillary tissue components. Here we present a reconstruction strategy recover not only scalar amount birefringence but also its optic axis orientation as function depth in from measurements with catheter-based polarization sensitive optical coherence tomography. A symmetry constraint, imaging backscatter direction, facilitates required compensation for wavelength-dependent transmission...

This study aimed to evaluate whether polarimetry, performed using a modified optical frequency domain imaging (OFDI) system, can improve the assessment of histological features relevant characterizing human coronary atherosclerosis. The microscopic structure and organization arterial wall influence polarization infrared light used by OFDI. Modification OFDI apparatus, along with recently developed image reconstruction methods, permits polarimetric measurements simultaneously conventional...

We address numerical dispersion compensation based on the use of fractional Fourier transform (FrFT). The FrFT provides a new fundamental perspective nature and role group-velocity in domain OCT. induced by 26 mm long water cell was compensated for spectral bandwidth 110 nm, allowing theoretical axial resolution air 3.6 μm to be recovered from degraded point spread function. Additionally, we present approach depth dependent simulations. Finally, show how optimized order parameter can used...

The degree of polarization (uniformity) has attracted increased interest as a functional contrast in optical coherence tomography (OCT). However, its computation from single state suggests an ambiguity that is strongly dependent on sample's orientation. We here propose improved metric to present depolarization with respect the system rather than propagating field. Using numerical simulations and frequency domain imaging, we evaluate conventional DOP(U) for different states compare...

The aims of this first-in-human pilot study intravascular polarimetry were to investigate polarization properties coronary plaques in patients and examine the relationship these features with established structural characteristics available conventional optical frequency domain imaging (OFDI) clinical presentation. Polarization-sensitive OFDI measures birefringence depolarization tissue together cross-sectional images subsurface microstructure. Thirty undergoing polarization-sensitive (acute...

Near-infrared photoacoustics receives increasing interest as an intravital modality to sense key biomolecules. One of the most central types biomolecules are lipids they constitute essential bio-hallmarks cardiovascular and metabolic diseases their in-vivo detection holds insightful information about disease progression treatment monitoring. However, full potential near-infrared photoacoustic for high-resolution high-sensitivity biomedical studies has so far not been exploited due a lack...

Fourier domain mode-locking (FDML) has been a popular laser design for high speed optical frequency imaging (OFDI) but the achievable coherence length, and therefore range, limited. The narrow instantaneous linewidth of comb (FC) FDML could provide an attractive platform as well long range OFDI. Unfortunately, aliasing artifacts arising from signals beyond principle measurement depth free spectral have prohibited use FC so far. To make enhanced length available, methods to manage such are...

Improving the axial resolution by providing wider bandwidth wavelength swept lasers remains an important issue for optical frequency domain imaging (OFDI).Here, we demonstrate a wide tuning range, all-fiber laser at center of 1250 nm combining two ring cavities that share single Fabry-Perot tunable filter.The contain semiconductor amplifiers with central wavelengths 1190 and 1292 nm, respectively.To avoid disturbing interference effects in overlapping spectral region, modulated order to...

A full quantitative evaluation of the depolarization light may serve to assess concentrations depolarizing particles in retinal pigment epithelium and investigate their role diseases human eye. Optical coherence tomography optical frequency domain imaging use spatial incoherent averaging compute depolarization. Depolarization depends on accurate measurements polarization states at receiver but also state incident upon within tissue. Neglecting this dependence can result artifacts renders...

Fiber-based polarization-sensitive optical frequency domain imaging is more challenging than free-space implementations. Using multiple input states, fiber-based systems provide sample birefringence information with the benefit of a flexible arm but come at cost increased system and acquisition complexity, either reduce speed or require bandwidth. Here we show that calibration single polarization state, configurations can approach conceptual simplicity traditional configurations. We remotely...

Intravascular polarimetry with polarization sensitive optical frequency domain imaging (PS-OFDI) measures properties of the vessel wall and offers characterization coronary atherosclerotic lesions beyond cross-sectional image arterial microstructure available to conventional OFDI. A previous study intravascular in cadaveric human arteries found that tissue birefringence depolarization provide valuable insight into key features plaques. In addition various components, catheter sample motion...

We present a versatile long coherence length swept-source laser design for optical tomography applications. This consists of polygonal spinning mirror and an gain chip in modified Littman–Metcalf cavity. A narrowband intra-cavity filter is implemented through multiple passes off diffraction grating set at grazing incidence. The key advantage this that it can be readily adapted to any wavelength regions which broadband chips are available. demonstrate by implementing sources 1650 nm, 1550...

In Fourier-domain optical coherence tomography (OCT), the finite bandwidth of acquisition electronics constrains depth range and speed system. Circular-ranging (CR) OCT methods use optical-domain compression to surpass this limit. However, CR-OCT system architectures prior reports were limited by poor stability confined 1.55 µm wavelength range. work, we describe a novel architecture that is free from these limitations. To ensure stable operation, temperature sensitive modules within...

Polarization-sensitive optical coherence tomography (PS-OCT) reveals the subsurface microstructure of biological tissue and provides information regarding polarization state light backscattered from tissue. Complementing OCT's structural signal with molecular imaging requires strategies to simultaneously detect multiple exogenous contrast agents high specificity in Specific detection probes enables parallel visualization physiological, cellular, processes. Here we demonstrate that, by...

We use the Pancharatnam-Berry phase as a multifunctional tool for low-coherence interferometry. This geometric shift enables instantaneous retrieval of quadrature components complex interferometric signal. The is independent wavelength and allows conjugate suppression 40 dB an optical bandwidth 115 nm. Furthermore, this paper investigates versatility to perform polarization sensitive measurements. Jones vector sample was obtained numerically, allowing birefringence axis calculation.

Techniques to differentiate between materials are a powerful addition the structural information traditionally available from optical coherence tomography images. We present label-free detection of water and lipid at micrometer scale by evaluating their unique dispersion properties. Using tri-band swept source configuration, we measure both β(2) β(3) show how identify two sample thicknesses 40 90 μm, respectively.

In Fourier-domain optical coherence tomography, an interference signal is generated that spans RF bandwidth proportional to the product of three parameters: imaging range, speed, and inverse axial resolution. Circular-ranging tomography (CR-OCT)architectures were introduced ease long-range by decoupling range from bandwidth. As a consequence, present CR-OCT systems resolve relative, but not absolute, depth location scatterers. We introduce here modified implementation uses degenerate...

We present speckle suppression and dispersion compensation for Fourier-domain optical coherence tomography based on fractional Fourier transforms of a single A scan. 1.54-fold reduction in contrast was achieved with group velocity compensation. The method is demonstrated biological samples using swept source configuration at 1310 nm spectral-domain system 840 nm.

Cardiac trabeculae are widely used as experimental muscle preparations for studying heart muscle. However, their geometry (diameter, length, and shape) can vary not only among samples, but also within a sample, leading to inaccuracies in estimating stress production, volumetric energy output, and/or oxygen consumption. Hence, it is desirable have system that accurately image each trabecula vitro during an experiment. To this end, we constructed optical coherence tomography implemented gated...

While it is a common practice to increase the speed of swept-source optical coherence tomography (OCT) systems by using high-speed source, this approach may not always be optimal. Parallelization in form multiple imaging beams an alternative approach, but scalable and low-loss multi-beam OCT architectures are needed capitalize on its advantages. In study, we demonstrate eight-beam system interferometer architecture comprising planar lightwave circuits (PLC) splitters, V-groove assemblies...

The differential Mueller matrix offers useful insight into the polarization properties of biological tissue imaged with sensitive optical coherence tomography. We present theory and experimentally demonstrate local depolarization in addition to retardation.

Polarization sensitive optical coherence tomography (PS-OCT) provides measures of tissue birefringence and depolarization. Here, we demonstrate catheter-based PS-OCT in the coronary arteries human patients to obtain valuable insight into morphology atherosclerotic plaques.

An integrated instrument is being developed to study live cardiac trabeculae, which capable of stimulating the muscle under controlled conditions while measuring heat production, force, and sarcomere length distribution. To improve accuracy estimation stress, strain, volumetric geometry must be known. A spectral domain optical coherence tomography system (SD-OCT) has been constructed calibrated image trabecula mounted inside instrument. This was above chamber a series equally-spaced...