This PDF file contains the front matter associated with SPIE Proceedings Volume 10416, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

In spectral domain optical coherence tomography (SD-OCT), any transverse motion component of a detected obliquely moving sample results in a nonlinear relationship between the Doppler phase shift and the axial sample velocity restricting phase-resolved Doppler OCT. To circumvent the limitation, we propose the lateral resonant Doppler flow quantification in spectral domain OCT, where the scanner movement velocity is matched to the transverse velocity component of the sample motion.

Spectrometer based and swept source based phase sensitive Fourier Domain OCT systems are compared in terms of the stability of the retrieved signal phase. The spectrometer based system performs with a significantly better phase stability with less uncertainty in the output, whereas the output of the swept source based system is influenced by the jitter noise that creates jumps to the retrieved phase. The experimentally obtained phase traces from the spectrometer based system match well to relevant mathematics.

Selective retina therapy and optical coherence tomography have been combined to monitor laser-tissue interaction in real-time. An ex-vivo study of porcine eyes unveils mechanisms that enable automated and accurate dose-control during laser-therapy.

An in-vivo anterior-segment optical coherence tomography with sub-micron isotropic resolutions is demonstrated on rat cornea. The opacity of the layered cornea was quantitatively analyzed. The morphology of corneal layers was well-depicted by the en-face image.

OCT imaging in the super-resolution regime was investigated using simulations and experiments. Samples of known thickness in the range 46-163 nm were fabricated and imaged. Measurements of the tear film lipid layer were performed.

A sequential multi-channel OCT prototype featuring high-speed fiber optical switches to enable inter A-scan (A-scan rate: 100 kHz) sample arm switching was developed and human retinal image data is presented.

Corneal B-scan images and signal-to-noise ratio measurements using ultra-high resolution Spectral Domain Optical Coherence Tomography (SD-OCT) are reported. A comparison of results is obtained using a Ti:Sa laser and a supercontinuum optical source, is performed. Beside some differences in the SNR, the images are strikingly similar.

We present the in-vivo imaging of the global mouse brain ischemia using Bessel beam optical coherence microscopy. This method allows to monitor changes in brain structure with extra control of blood flow during the process of artery occlusion. The results show the capability and sensitivity of OCM system with Bessel beam to analyze brain plasticity after severe injury within a period of 8 days.

The feasibility of using time domain optical coherence tomography (TD-OCT) to detect compound action potential in a peripheral nerve and the setup characteristics, are studied through the use of finite-difference time-domain (FDTD) technique.

We present a novel software method (master-slave) to facilitate operation of any SDOCT system. This method relaxes constraints on dispersion compensation and k-domain re-sampling in SDOCT methods without requiring any changes in the hardware used.

We present a novel approach for imaging through scattering media by combining single-pixel imaging techniques and Fourier spatial filtering. Experimental improvements in both penetration depth and spatial resolution of the acquired images are shown.

The inhomogeneity of scattering medium distorts the propagation of the waves, which has been detrimental to the performance of optical imaging. The operating time of the traditional solutions will be very long as the scanning is necessary during the imaging. A recovery solution based on spatial optical transmission matrix has been proposed. With the acquiring of the spatial optical transmission matrix, the incident object wave will be recovered directly from the distorted transmitted wave, in this way, only a single shot is needed during the imaging. The effectiveness of this method has been proved by the simulation and experiment, the principle is simpler and the algorithm is more efficient, which are beneficial to the imaging through the scattering medium.

A multi-functional OCT approach is used to identify different tissue types during the early development of spontaneous neovascularizations in the mouse retina based on their intrinsic optical properties.

The early non-invasive diagnosis of epithelial tissue alterations in daily clinical routine is still challenging. Since optical coherence tomography (OCT) shows the potential to differentiate between benign and malignant tissue of primal endothelium, OCT could be beneficial for the early diagnosis of malignancies in routine health checks. In this research, a new handheld endoscopic scanning unit was designed and connected to a spectral domain OCT system of our workgroup for the in vivo imaging of the human oral mucosa.

By taking multiple input-output measurements, it is shown how to determine the input to an optical system that corrects unknown phase aberrations without interferometric measurements or online iterative optimization within a couple of seconds. It is shown to work in simulations and experiment. This technique may also be used to acquire the complex field in the pupil, hereby permitting a complex field image to be acquired.

Dispersion mismatch between the two arms of an Optical Coherence Tomography (OCT) interferometer causes degradation of the image resolution. However, dispersion in tissue is specific to the chemical constituents of the cells and can therefore carry diagnostically useful information. Unfortunately, dispersion measurement techniques, presented so far in the literature, require the presence of strong distinct reflections in the OCT image which are rarely present when imaging tissues in vivo. The novel method presented here relies on the image speckle to calculate the PSF degradation and is therefore applicable to any tissue and can be implemented in vivo and in situ. The resolution degradation is estimated using a Wiener-type deconvolution and was verified ex vivo resulting in Group Velocity Dispersion (GVD) values comparable to the standard techniques. This technique has also been applied to normal and malignant samples of human colon to evaluate its applicability for cancer diagnosis. Using the statistics of the GVD estimate, the tissue classification resulted in 93% sensitivity and 100% specificity (96% correct classification rate). The success of these preliminary results indicates the potential of the proposed method which should be further.

We apply first order perturbation theory and reciprocity to the scalar radiative transport equation for the temporal field auto-correlation function to study its sensitivity to changes in the Brownian motion of the constituent scattering particles.

We present a new design of a 1060nm Fourier Domain Mode Locked-Laser (FDML-Laser) that combines 1.67 MHz A-scan rate with a centimeter scale coherence length. The extended coherence length is achieved by synchronizing the cavity roundtrip time over the 75 nm sweep with a relative accuracy of 10^-7. We will show that this requires careful combination of multiple fiber types in the cavity with a gradient heated chirped Fiber Bragg grating.

We show for the first time FF-OCT combined with SD-OCT for real time matching of the optical path length of FF-OCT to demonstrate high resolution en face retinal imaging.

We demonstrate that the 3.2 MHz a-scan rate and the improved coherence of our new low noise FDML laser enables live 3D-OCT with different spectral zooms and up to 10 cm of imaging range.

A few-mode fiber based detection for OCT systems is presented. The capability of few-mode fibers for delivering light through different fiber paths enables the application of these fibers for angular scattering tissue character- ization. Since the optical path lengths traveled in the fiber change between the fiber modes, the OCT image information will be reconstructed at different depth positions, separating the directly backscattered light from the light scattered at other angles. Using the proposed method, the relation between the angle of reflection from the sample and the respective modal intensity distribution was investigated. The system was demonstrated for imaging ex-vivo brain tissue samples of patients with Alzheimer’s disease.

In this report, the benefits that the Master/Slave (MS) implementation of optical coherence tomography (OCT) can bring to a Gabor filtering (GF) imaging instrument are illustrated. The MS allows simultaneous display of three categories of images in one frame: multiple depth en-face OCT images, two B-scan OCT and a confocal like image. The power of MS is illustrated here by showing 3D images of constant transversal resolution from different objects, obtained by merging sub-volumes collected for four different focus positions. By combining the two techniques, GF and MS, a powerful imaging instrument is demonstrated. We show that when more than four focus positions are required, MS can produce fused volumes faster than the conventional FT based procedure.

We experimentally compare the optimal steepest ascent algorithm and the sequential method for feedback based iterative wavefront shaping. The former converges significantly faster and leads to a sharp focus behind a turbid medium.

OCT-based local strain relaxation/creep evaluation is an emerging tool for tissue viscoelasticity characterization. We present a tool for 2D visualization of local strain relaxation and creep time/rate inside the tissue.

For the simulation of Fourier domain optical coherence tomography (OCT) images, analytical solutions of Maxwell’s equations for single and multiple cylinder scatterers are presented. With the angular spectrum of plane waves, a Gaussian beam is implemented to scan the cylinder samples. Two-dimensional B-scans are simulated and the origins of the signals are discussed. For an incident plane wave, a line scan is shown for single and multiple scattering.

Ocular optical coherence tomography at the wavelengths ranges of 850 and 1060 nm have been integrated with a confocal scanning laser ophthalmoscope eye-tracker as a clinical commercial-class system. Collinear optics enables an exact overlap of the different channels to produce precisely overlapping depth-scans for evaluating the similarities and differences between the wavelengths to extract additional physiologic information. A reliable segmentation algorithm utilizing Graphcuts has been implemented and applied to automatically extract retinal and choroidal shape in cross-sections and volumes. The device has been tested in normals and pathologies including a cross-sectional and longitudinal study of myopia progress and control with a duplicate instrument in Asian children.

The double pass imaging method is used to obtain the point spread function of a patient’s eye; however it suffers from speckle formation. Here we present a comparison of speckle formation in double pass imaging using three different semiconductor-based light sources.