Non-invasive functional imaging of molecular and cellular processes vision is expected to have immense impact on research clinical diagnostics. Although suitable intrinsic optical signals (IOS) been observed ex vivo in immobilized animals vivo, it was so far not possible obtain convincing IOS photoreceptor activity humans vivo. Here, we spatially temporally clearly resolved changes the path length outer segment as response an stimulus living human. To these changes, evaluated phase data a...

Certain topics in research and advancements medical diagnostics may benefit from improved temporal spatial resolution during non-invasive optical imaging of living tissue. However, so far no technique can generate entirely diffraction-limited tomographic volumes with a single data acquisition, if the target moves or changes rapidly, such as human retina. Additionally, presence aberrations represent further difficulties. We show that simple interferometric setup-based on parallelized...

We demonstrate a new noninvasive method to assess biomechanical properties of the retinal vascular system. Phase-sensitive full-field swept-source optical coherence tomography (PhS-FF-SS-OCT) is used investigate dynamics at unprecedented temporal resolution. The motion tissue that induced by expansion vessels therein measured with an accuracy about 10 nm. pulse shapes arterial and venous pulsations, their delays, as well frequency-dependent propagation through capillary bed, are determined....

Scanning optical coherence tomography (OCT) is limited in sensitivity and resolution by the restricted focal depth of confocal detection scheme. Holoscopy, a combination holography Fourier-domain full-field OCT, proposed as way to detect photons from all depths sample volume simultaneously with uniform lateral resolution, even at high NAs. By using scalar diffraction theory, frequently applied digital holographic imaging, we fully reconstruct object field depth-invariant imaging quality. In...

Swept-source optical coherence tomography (SS-OCT) is sensitive to sample motion during the wavelength sweep, which leads image blurring and artifacts. In line-field full-field SS-OCT parallelization achieved by using a line or area detector, respectively. Thus, approximately 1000 lines images at different wavenumbers are acquired. The sweep duration identically with acquisition time of complete B-scan volume, rendering parallel more artifacts than scanning OCT. effect axial on measured...

With a simple setup, mainly composed of low coherence light source and camera, full-field optical tomography (FF-OCT) allows volumetric tissue imaging. However, fringe washout constrains its use in retinal Here, we present novel motion-insensitive approach to FF-OCT, which introduces path-length differences between the reference sample neighboring pixels using an off-axis beam. The temporal carrier frequency scanned time-domain OCT is replaced by spatial frequency. Volumetric in-vivo FF-OCT...

Functional retinal imaging, especially of neuronal activity non-invasively in humans, is tremendous interest. Although the activation photoreceptor cells (PRCs) could be detected imaging function other neurons had been so far hardly possible. Here, using phase-sensitive full-field swept-source optical coherence tomography (FF-SS-OCT), we show simultaneous and ganglion cell layer/inner plexiform layer (GCL/IPL). The signals from GCL/IPL are 10-fold smaller than those PRC were detectable only...

Holoscopy is a tomographic imaging technique that combines digital holography and Fourier-domain optical coherence tomography (OCT) to gain tomograms with diffraction limited resolution uniform sensitivity over several Rayleigh lengths. The lateral image information calculated from the spatial interference pattern formed by light scattered sample reference beam. depth obtained spectral dependence of recorded holograms. Numerous holograms are acquired at different wavelengths then...

In numerous applications, Fourier-domain optical coherence tomography (FD-OCT) suffers from a limited imaging depth due to signal roll-off, focal range, and autocorrelation noise. Here, we propose parallel full-field FD-OCT method that uses swept laser source an area camera in combination with off-axis reference, which is incident on the at small angle. As digital holography, this angle separates signals complex conjugated mirror image actual Fourier space. We demonstrate by reconstructing...

Nearly real-time visualization of 3-D volumes is crucial for the use optical coherence tomography (OCT) during microsurgery. With an ultrahigh speed spectral domain OCT coupled to a surgical microscope, on-line display 7.2 rendered at 87 megapixels per second demonstrated. Calculating A-scans from spectra done on quad-core personal computer (PC), while dedicated software rendering executed high performance video card. Imaging practically only limited by readout camera. First experiments show...

Aberration-corrected imaging of human photoreceptor cells, whether hardware or software based, presently requires a complex and expensive setup. Here we use simple inexpensive off-axis full-field time-domain optical coherence tomography (OCT) approach to acquire volumetric data an in vivo retina. Full are recorded 1.3 s. After computationally correcting for aberrations, single cells were visualized. In addition, the numerical correction ametropia is demonstrated. Our implementation combines...

Full-field swept-source optical coherence tomography (FF-SS-OCT) was recently shown to allow new and exciting applications for imaging the human eye that were previously not possible using current scanning OCT systems. However, especially when cameras do acquire data with hundreds of kHz frame rate, uncorrected phase errors due axial motion lead a drastic loss in image quality reconstructed volumes. Here we first give short overview recent advances techniques parallelized finally present an...

Computational adaptive optics (CAO) is emerging as a viable alternative to hardware-based optics-in particular when applied optical coherence tomography of the retina. For this technique, algorithms are required that detect wavefront errors precisely and quickly. Here we propose an extension frequently used subaperture image correlation. By applying algorithm iteratively and, more importantly, comparing each not central but several randomly selected apertures, improved aberration correction....

Abstract Phase-sensitive coherent imaging exploits changes in the phases of backscattered light to observe tiny alterations scattering structures or variations refractive index. But moving scatterers a fluctuating index decorrelate and speckle patterns images. It is generally believed that once pattern has changed, are scrambled any meaningful phase difference original removed. As consequence, diffusion tissue motion cannot be resolved, prevent phase-sensitive biological specimens. Here, we...

Doppler optical coherence tomography (OCT) quantifies axial motion with high precision, whereas lateral cannot be detected by a mere evaluation of phase changes. This problem was solved the introduction three-beam OCT, which, however, entails experimental effort. Here, we present numerical analogue to this approach. Phase-stable complex-valued OCT datasets, recorded full-field swept-source are filtered in Fourier domain limit imaging different computational subapertures. These used calculate...

Non-invasive spatially resolved functional imaging in the human retina has recently attracted considerable attention. Particularly of bipolar and ganglion cells could aid studying neuronal activity humans, including an investigation processes central nervous system. Recently, we imaged inner layers by measuring nanometer-size changes within plexiform layer (IPL) using phase-sensitive optical coherence tomography (OCT). In IPL, there are connections between that dedicated to processing...

We demonstrate a full-field swept-source OCT using an off-axis geometry of the reference illumination. By holographic refocusing techniques, uniform lateral resolution is achieved over measurement depth approximately 80 Rayleigh lengths. Compared to standard on-axis setup, artifacts and autocorrelation signals are suppressed doubled by resolving complex conjugate ambiguity. Holographic was done efficiently Fourier-domain resampling as demonstrated before in inverse scattering holoscopy. It...

In recent years, optoretinography has become an important functional imaging method for the retina, as light-evoked changes in photoreceptors have been demonstrated a large number of different OCT systems. Full-field swept-source optical coherence tomography (FF-SS-OCT) is particularly phase-stable, and it currently only technique sensitive enough to detect smaller inner plexiform layer (IPL). However, resolution state-of-the art FF-SS-OCT systems not high distinguish individual...

In OCT imaging the spectra that are used for Fourier transformation in general not acquired linearly k-space. Therefore one needs to apply an algorithm re-sample data and finally do Transformation gain depth information. We compare three algorithms (Non-Equispaced DFT, interpolated FFT Non-Equispaced FFT) this purpose terms of speed accuracy. The optimal depends on device (speed, SNR) object.

Full-field swept-source optical coherence tomography (FF-SS-OCT) and laser Doppler holography (LDH) are two holographic imaging techniques presenting unique capabilities for ophthalmology. We report on interlaced FF-SS-OCT LDH with a single instrument. Effectively, retinal blood flow pulsation could be quasi-simultaneously monitored. This instrument holds potential wide scope of ophthalmic applications.

Optical coherence tomography (OCT) images scattering tissues with 5 to 15 μm resolution. This is usually not sufficient for a distinction of cellular and subcellular structures. Increasing axial lateral resolution compensation artifacts caused by dispersion aberrations required achieve includes defocus which limit the usable depth field at high OCT gives access phase scattered light hence correction possible numerical algorithms. Here we present unified dispersion/aberration based on...

A method for numerical estimation and correction of aberrations the eye in fundus imaging with optical coherence tomography (OCT) is presented. Aberrations are determined statistically by using estimate based on likelihood function maximization. The can be considered as an extension phase gradient autofocusing algorithm synthetic aperture radar to 2D aberration correction. efficacy proposed has been demonstrated OCT 6λ aberrations. After correction, single photoreceptors were resolved. It...