Terahertz Imaging System for Medical Applications and Related High Efficiency Terahertz Devices

Ouchi, Toshihiko; Kajiki, Kousuke; Koizumi, Takayuki; Itsuji, Takeaki; Koyama, Yasushi; Sekiguchi, Ryota; Kubota, Oichi; Kawase, Kodo

doi:10.1007/s10762-013-0004-5

Cited by 77 publications

(29 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…THz spectroscopy and imaging were actively used for this purpose during the past twenty years in the wide area of security applications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. At the same time, this technique starts to be widely used for the non-destructive testing, for quality inspection of pharmaceuticals and food products as well as for medical applications [20][21][22][23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

High effective THz-TDS method for the detection and identification of substances in real conditions

et al. 2016

View full text Add to dashboard Cite

Low efficiency of the standard THz-TDS method for the detection and identification of substances is demonstrated. For this purpose, we use a few examples. In the first example, we model the noisy THz signals transmitted through the amphetamine-type stimulant in real conditions. Namely, with a temperature 18° C, the relative humidity of about 50 % and the distance between the parabolic mirror and the object about of 3.5 meters. We show that the standard THz-TDS method reveals the spectral features of many neutral substances and explosives in the noisy THz signals from the illicit stimulant MA, at the same time this method is not able to detect the presence of this stimulant in the noisy signals. The second example is the detection and identification of plastids with inhomogeneous surface in reflection mode. We show that inhomogeneous surface distorts spectral characteristics of the reflected THz signal main pulse, which cannot be used for the detection and identification of the plastids by means of the THz TDS method. In the last example we show that even under laboratory conditions (at short distance from the receiver), THz TDS detects in the semiconductors the absorption frequencies, which belong to both hazardous and neutral substances. To overcome this disadvantage, we propose to use the time-dependent spectrum of the THz pulse, transmitted through or reflected from a substance. For quality assessment of the presence of the standard substance absorption frequency in the signal under analysis, we use time-dependent integral correlation criteria. The influence of aperture placed in front of the sample on spectral properties of silicon wafers with different resistivity is demonstrated as well.Keywords: reflected and transmitted THz pulse, noisy THz pulse, method of spectral dynamics analysis, integral correlation criteria, identification of explosives and drugs. *vatro@cs.msu.ru; phone 7 495 939-5255; fax 7 495 939-2597

show abstract

Section: Introductionmentioning

confidence: 99%

High effective THz-TDS method for the detection and identification of substances in real conditions

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Interest in biomedical THz research is growing rapidly [56,57]. THz radiation has very low photon energy and thus does not cause any ionization hazard for biological tissues.…”

Section: Biomedical Applicationsmentioning

confidence: 99%

Terahertz Pulse Detection Techniques and Imaging Applications

Chen¹,

Guo²

2017

Terahertz Spectroscopy - A Cutting Edge Technology

View full text Add to dashboard Cite

Recent years have witnessed successful developments of detection techniques of teraherz (THz) pulse radiation and its imaging applications such as security, medicine and environmental sensing, to name an important few. Progress of detection techniques has been made in many aspects, including detection sensitivity, real-time detection, roomtemperature operation, detection bandwidth and dynamic range, spatial (wavefront) and temporal proiles and so on. New detection techniques utilizing cuting-edge materials, sensors, systems and even novel detection mechanisms contribute to advances in teraherz pulse detection. While detection techniques continuously improve, teraherz pulsed imaging (TPI) also inds broad and intriguing applications. For instance, TPI has shown applications in nondestructive evaluation in pharmaceutics, biomedical characterization of tissues, medical diagnosis of cancers, identiication of explosive hazards and examination of art and archeology. The chapter highlights recent progress of teraherz pulse detection techniques and imaging applications.

show abstract

“…The optical imaging using the THz light is expected to be new medical imaging system because of its nondestructive nature and its relatively low energy [1,2,3]. However, the optical diffraction limit severely restricts the focusing spot of light and blur the optical image.…”

Section: Introductionmentioning

confidence: 99%

Hybrid-lens for Terahertz Subwavelength Focusing beyond the Diffraction Limit

Tapsanit

Yamashita

Otani

2016

View full text Add to dashboard Cite

Abstract. The relatively low energy of the terahertz light (THz, 1 THz=4.14 meV) promises the non-invasive optical imaging of the biomedical objects. However, the THz light inherently suffers the optical diffraction limit and the subwavelength microstructures cannot be resolved. We propose the planar hybrid-lens comprising the multiple slits and the two-dimensional rod array for the subwavelength focusing of the THz light beyond the diffraction limit. The hybrid-lens is investigated by the finite difference time domain simulation (FDTD). The spectra of the rod array obtained by FDTD are compared with the spectra calculated by the analytical model. The subwavelength focal spot about 20 µm (λ/7.5) at the frequency 2 THz is demonstrated by FDTD. The array of the subwavelength focal spots on the opposite side of the multiple slits are generated by the interferences of the Floquet-Bloch waves which can be guided through the rod array. The hybrid-lens can function as the subwavelength focusing and the substrate simultaneously which may serve as the new tool in the high-speed imaging and sensing of the subwavelength biomedical objects by using the THz light.

show abstract

Terahertz Imaging System for Medical Applications and Related High Efficiency Terahertz Devices

Cited by 77 publications

References 32 publications

High effective THz-TDS method for the detection and identification of substances in real conditions

High effective THz-TDS method for the detection and identification of substances in real conditions

Terahertz Pulse Detection Techniques and Imaging Applications

Hybrid-lens for Terahertz Subwavelength Focusing beyond the Diffraction Limit

Contact Info

Product

Resources

About