A novel optical coherence tomography system that can carry out scanless two dimensional imaging without Fourier change can be proposed and proven. systems were built in time-domain where axial checking systems in the research arm were required as well as the checking systems may limit the imaging acceleration and range. As opposed to time-domain OCT (TD-OCT), the Rabbit Polyclonal to GUSBL1 Fourier-domain OCT (FD-OCT) is capable of doing cross-sectional imaging without axial scan in the research arm where in fact the optical hold off component can be replaced by a set reflection mirror as well as the photodetector can be replaced with a spectrometer [8,9]. This sort of OCT can be known as spectral-domain OCT (SD-OCT) where the cross-sectional picture can be acquired after a Fourier change from the spectral interferogram assessed from the spectrometer. Lately, a different type of FD-OCT originated when a time-encoded swept resource was utilized as the source of light [10,11]. This sort of OCT can be known as swept-source OCT (SS-OCT) when a photodetector actions the spectral parts during the checking period for building from the spectral interferogram. Compared to TD-OCT, FD-OCT possesses the advantages of high speed and high sensitivity. However, the imaging range in axial direction of FD-OCT is limited by the resolution of spectral interferogram. Furthermore, mirror image and autocorrelation noise are resulted from Fourier transform of the spectral interferogram that need to be resolved by post processing methods [12C14]. Recently, various full-field and single-shot OCT techniques were proposed to improve the imaging speed by eliminating scanning. However, most of these techniques can only provide images or need a Fourier transform in the image processing [15C22]. In addition, grating based scanless optical delay predicated on Littrow construction that uses either place or line construction based test scanning in time domain configuration was demonstrated by several groups [23,24]. In this paper, a spatial-domain OCT system that can perform scanless two dimensional imaging without Fourier transform is proposed and demonstrated. Because of its simple configuration and operation as well as no scanning or moving part in the system, it has the potential for the development of a compact OCT system by using a compact light source. 2.?Experimental setup Figure?1 shows the layout and experimental setup of the scanless transform-free spatial-domain OCT system. A mode-locked Ti:sapphire laser (FEMTOLASERS, INTEGRAL PRO) with output power of 122?mW was used as the light source. The central wavelength and full width at half maximum of the output spectrum were 800?nm and 138?nm, respectively. An adjustable neutral-density filter (NDF) was released to regulate the laser beam power and a beam expander was utilized to increase the laser. The charged power from the laser incident for the beamsplitter was measured to become 87?mW. The laser was divided having a beamsplitter into sample and reference beams then. In the research arm, an NDF was released to adjust the energy of research beam and a dispersion compensator was utilized to pay the dispersion mismatch between your test and research beams. A convex cylindrical reflection was utilized to reveal and increase the research beam that led to a protracted spatial distribution of optical hold off along the Z-direction in Fig.?1. The part of shown reference beam SB 431542 pontent inhibitor that could not be event inside the sensing selection of the charge-coupled gadget (CCD) camcorder was clogged. In the test arm, a cylindrical zoom lens with focal amount of 50?mm was introduced to target the test SB 431542 pontent inhibitor beam onto the test in the Y-direction to create a focused range beam along the X-direction in Fig.?1. Another NDF was introduced between the beamsplitter and cylindrical lens in the sample arm when a sample with high reflectivity was imaged. At the detection end, the two-dimensional tomographic image of the sample was captured with a CCD camera (Basler, piA1900-32gm) with a bit depth and a full-well-capacity of 12 bits and 40,000 -, respectively. Open in a separate window Fig. 1. The (a) layout and (b) experimental setup of the spatial-domain OCT system. L, light source; NDF1, NDF2 and NDF3, neutral-density filters; BE, beam expander; BS, beamsplitter; BB, beam block; DC, dispersion compensator; SB 431542 pontent inhibitor CM, cylindrical mirror; CL, cylindrical lens; SS, sample stage; CCD, CCD camera. In such an arrangement, the distribution of optical delay of the reflected reference beam along the Z-direction in Fig.?1 is effectively equivalent to.