ABSTRACT
High-speed complex full-range Fourier domain optical coherence tomography (FD-OCT) is demonstrated. In this FD-OCT, the phase modulation of a reference beam (M scan) and transversal scanning (B scan) are simultaneously performed. The Fourier transform method is applied along the direction of the B scan to reconstruct complex spectra, and the complex spectra comprise a full-range OCT image. Because of this simultaneous B-M-mode scan, the FD-OCT requires only a single A scan for each single transversal position to obtain a full-range FD-OCT image. A simple but slow version of the FD-OCT visualizes the cross section of a plastic plate. A modified fast version of this FD-OCT investigates a sweat duct in a finger pad in vivo and visualizes it with an acquisition time of 27 ms.
Subject(s)
Image Enhancement/instrumentation , Image Interpretation, Computer-Assisted/instrumentation , Spectroscopy, Fourier Transform Infrared/instrumentation , Tomography, Optical Coherence/instrumentation , Computer Systems , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Spectroscopy, Fourier Transform Infrared/methods , Systems Integration , Tomography, Optical Coherence/methodsABSTRACT
We demonstrate 3-D optical coherence tomography using only 1-D mechanical scanning. This system uses the principle of Fourier domain optical coherence tomography for depth resolution, 1-D imaging for lateral vertical resolution, and mechanical scanning by a galvanometer for lateral horizontal resolution. An in vivo human fingerpad is investigated in three dimensions with an image size of 480 points (vertical) x 300 points (horizontal) x 1024 points (depth), which corresponds to 2.1 x 1.4 x 1.3 mm. The acquisition time for a single cross section is 1 ms and that for a single volume is 10 s. The system sensitivity is 75.6 dB at a probe beam power of 1.1 mW.
Subject(s)
Dermoscopy/instrumentation , Fingers/anatomy & histology , Image Enhancement/instrumentation , Imaging, Three-Dimensional/instrumentation , Skin/cytology , Tomography, Optical Coherence/instrumentation , Dermoscopy/methods , Equipment Design , Equipment Failure Analysis , Fourier Analysis , Humans , Image Enhancement/methods , Imaging, Three-Dimensional/methods , Reproducibility of Results , Sensitivity and Specificity , Tomography, Optical Coherence/methodsABSTRACT
Standard Fourier domain optical coherence tomography (FD-OCT) and line-field Fourier domain optical coherence tomography (LF-FDOCT) are described. The standard FD-OCT has the measurement speed of 36 frames/sec and one frame consisting 500 A-scans. The LF-FDOCT is an improved version of FD-OCT and determines a cross section of a sample without any mechanical scanning. The LF-FDOCT has the measurement speed of 30 frames/sec, which is corresponding to 480 KH/ A-scan. A galvano-meter is introduced into the LF-FDOCT and it enables three-dimensional OCT measurement with only one-dimensional mechanical scanning.
ABSTRACT
A novel optical scheme for a phase shifting method of Fourier domain optical coherence tomography is presented. With this method we avoid a mechanical scan for phase shifting (mechanical M-scan) by using a reference beam with tilted wavefront. The principle of this system is confirmed with a simple mirror object. This method is applied on a biological sample and used to investigate a porcine anterior eye chamber.
