Leitgeb R, Hitzenberger CK, Fercher AFPerformance of Fourier domain versus time domain optical coherence tomography. Opt Express 11:889-894

University of Vienna, Wien, Vienna, Austria
Optics Express (Impact Factor: 3.49). 05/2003; 11(8):889-94. DOI: 10.1364/OE.11.000889
Source: PubMed


In this article we present a detailed discussion of noise sources in Fourier Domain Optical Coherence Tomography (FDOCT) setups. The performance of FDOCT with charge coupled device (CCD) cameras is compared to current standard time domain OCT systems. We describe how to measure sensitivity in the case of FDOCT and confirm the theoretically obtained values. It is shown that FDOCT systems have a large sensitivity advantage and allow for sensitivities well above 80dB, even in situations with low light levels and high speed detection.

Download full-text


Available from: Rainer A Leitgeb
  • Source
    • "the OCT axial scan rates to hundreds of KHz or even above 1 MHz. Typically, the spectral-domain methods suffer a sensitivity roll-off due to depth-dependent sensitivity loss and mirror-conjugate images [15], which limit the total imaging depth to a few millimeters [12]–[14], [16]. However, recent advance in short-cavity MEMS-VCSEL has dramatically mitigated this limitation, achieving imaging depths as large as tens of centimeters [17], [18]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We report here a demonstration of depth-resolved optical imaging based on optical sampling by cavity tuning (OSCAT). Both optical coherence tomography and three-dimensional surface mapping are performed using an OSCAT imager. Limitations on axial resolution and pulse repetition-rate stability are discussed and viable solutions are provided. Compared to other ultrafast laser-based schemes such as asynchronous optical sampling, OSCAT provides a simple, cost-effective solution for rapid, large-depth noninvasive imaging.
    Full-text · Article · Aug 2015 · IEEE Photonics Technology Letters
  • Source
    • "A 1310 nm spectral/Fourier domain OCT microscope (Leitgeb et al., 2003), shown in Supplementary Fig. 1A, was constructed for in vivo imaging of the rat cerebral cortex. The light source consisted of two superluminescent diodes combined using a 50/50 fiber coupler to yield a bandwidth of 150 nm. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The BOLD (blood-oxygen-level dependent) fMRI (functional Magnetic Resonance Imaging) signal is shaped, in part, by changes in red blood cell (RBC) content and flow across vascular compartments over time. These complex dynamics have been challenging to characterize directly due to a lack of appropriate imaging modalities. In this study, making use of infrared light scattering from RBCs, depth-resolved Optical Coherence Tomography (OCT) angiography was applied to image laminar functional hyperemia in the rat somatosensory cortex. After defining and validating depth-specific metrics for changes in RBC content and speed, laminar hemodynamic responses in microvasculature up to cortical depths of >1 mm were measured during a forepaw stimulus. The results provide a comprehensive picture of when and where changes in RBC content and speed occur during and immediately following cortical activation. In summary, the earliest and largest microvascular RBC content changes occurred in the middle cortical layers, while post-stimulus undershoots were most prominent superficially. These laminar variations in positive and negative responses paralleled known distributions of excitatory and inhibitory synapses, suggesting neuronal underpinnings. Additionally, the RBC speed response consistently returned to baseline more promptly than RBC content after the stimulus across cortical layers, supporting a "flow-volume mismatch" of hemodynamic origin.
    Full-text · Article · Aug 2014 · NeuroImage
  • Source
    • "The combination of these characteristics with the transparency of ocular media, as well as its thin layer composition, paved the way to OCT’s most prominent applications in ophthalmology [5]. Until today, the initially developed time domain OCT technique was almost entirely replaced by Fourier domain (FD) techniques, mainly due to sensitivity and imaging speed advantages [6–8]. Nowadays two different FD-OCT techniques, spectral domain (SD) [9] and swept source OCT (SS-OCT) [10] are used. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a newly developed single mode fiber based swept source polarization sensitive optical coherence tomography system using a single input state at 1040 nm. Two non-polarizing fiber based beam splitters are combined to form a Mach-Zehnder interferometer, while two polarizing beam splitters are used to obtain a polarization sensitive detection. Both types of beam splitters solely feature conventional single mode fibers. Polarization control paddles are used to set and maintain the polarization states in the fibers of the interferometer and detection unit. By use of a special paddle alignment scheme we are able to eliminate any bulk optic wave plates and polarization maintaining fibers in the interferometer and detection paths while preserving the advantages of a single input state system that illuminates the sample with circularly polarized light. To demonstrate the capabilities of our system, we performed retinal measurements on healthy human volunteers.
    Full-text · Article · Aug 2014 · Biomedical Optics Express
Show more