A miniaturized fiber-coupled terahertz endoscope system

Division of Electrical and Electronics Engineering, Korea Maritime University, Busan 606-791, Korea.
Optics Express (Impact Factor: 3.49). 09/2009; 17(19):17082-7. DOI: 10.1364/OE.17.017082
Source: PubMed


In this study, we have designed, fabricated, and characterized a miniaturized optical fiber-coupled terahertz (THz) endoscope system. The endoscopic system utilized a photoconductive generator and detector driven by a mode-locked Ti:sapphire laser. In reflection mode, the endoscope showed a high signal-to-noise ratio and a wide frequency spectrum similar to the conventional THz time-domain spectroscopic system. The cross section of the endoscope including generator and detector head is (2 x 4 mm) x 6 mm, which is small enough to be inserted into a human body. For a feasibility test, the endoscopic system was used to measure reflective THz signals from the side wall of the mouth, tongue, and palm skin as well as from water for comparison. The absorption and refractive index of the side wall of the mouth and tongue were similar to those of water but those of the palm skin were less than water.

Download full-text


Available from: Joo-Hiuk Son, Dec 08, 2014
  • Source
    • "This study adds to the knowledge base of useful guidelines in choosing the proper lens for a terahertz PC antenna [17e21]. In addition, the study of a high-performance small substrate lens would be useful for several specific applications demanding miniaturization such as a fiber-coupled terahertz endoscope system [22] or a fiber-pigtailed terahertz imaging system [23] "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, a study of a stripline dipole antenna on a substrate lens used as a photoconductive detector in a terahertz system is presented. The traveling-wave behavior of the stripline dipole and the influence of the substrate lens are investigated over a broad frequency range up to 5.0 THz. The numerical results show that the lens shape represented by the ratio of the extension length to the lens radius plays an important role in maximizing the antenna gain and radiation spectral bandwidth. The gain response exhibited an increased level of sensitivity to the lens shape as the lens size increased, and this is particularly important in optimizing large substrate lenses. Improvements in the gain level over the entire frequency range of interest were observed as the lens diameter increased. This study provides helpful guidelines in choosing and optimizing a substrate lens designed for a terahertz photoconductive antenna, which is particularly useful for specific applications requiring a miniaturized photoconductive antenna design.
    Current Applied Physics 05/2014; 18(4):2014. DOI:10.1016/j.cap.2014.05.005 · 2.21 Impact Factor
    • "However, diagnosis with THz imaging does not involve a waiting period to confirm the cryogenic histology at the time of surgery. It is possible to confirm the initial diagnosis in vivo without excising the tissue, if THz imaging is used as an endoscopic procedure in the oral cavity [30]. In addition, the interiors of biological samples can also be revealed by reconstructing a time-domain waveform from a THz B-scan image. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We imaged a single case of oral malignant melanoma using terahertz (THz) reflection imaging at room temperature (20 °C) and below freezing (-20 °C). A malignant nodule beneath the oral tissue surface was visualized using 2-D and B-scan THz imaging techniques. The THz images were well correlated with the histological findings. The nodule was found to have lower water content than that of normal cells, and this water effect may have influenced the THz refractive index and absorption coefficient at 20 °C. The THz spectroscopic image of the frozen tissue at -20 °C showed better contrast because of the lack of liquid water; this implies that there are significant structural differences between malignant oral melanoma cells and normal mucosal cells. The better contrast in the frozen tissue images was due to the greater penetration of THz radiation into the sample. This temperature-dependent THz imaging approach demonstrated the feasibility of accurate imaging of the oral tumor tissue.
    IEEE Journal of Biomedical and Health Informatics 07/2013; 17(4):779-784. DOI:10.1109/JBHI.2013.2252357 · 1.44 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Sensing applications of THz technology include applications for space exploration, detection of concealed objects, explosive identification, and THz cancer detection. This paper will review these and other emerging applications and existing and potential THz sources and detectors, including photonic and electronic THz devices, such as plasmonic field effect transistors capable of detecting and emitting THz radiation. Plasma wave electronics devices demonstrated THz detection using GaAs-based and GaN-based HEMTs, Si MOS, SOI, and FINFETs and FET arrays. This technology has potential to become a dominant THz electronics technology.
    Proceedings of the 19th ACM Great Lakes Symposium on VLSI 2009, Boston Area, MA, USA, May 10-12 2009; 01/2009
Show more