US Patent Application-REFLECTIVE DETECTION DEVICE

United States Patent Application 20180003564
Inventors:
Kawakami, Hideyuki (Kyoto, JP) 
Kim, Jae-young (Kyoto, JP) 
Mukai, Toshikazu (Kyoto, JP) 
Tsuruda, Kazuisao (Kyoto, JP) 

http://www.freepatentsonline.com/y2018/0003564.html

A reflective detection device, includes: oscillation element oscillating a terahertz wave; exit part from which the terahertz wave exits; incident part to which the terahertz wave reflected from a detection target is incident; and detection element detecting the terahertz wave incident to the incident part, wherein the exit part and the incident part are disposed on one side in first direction and are spaced apart from each other in second direction with respect to the detection target, the terahertz wave exiting from the exit part travels to propagate from the exit part toward the incident part in the second direction along a direction toward the detection object in the first direction, and the terahertz wave incident to the incident part travels to propagate from the exit part toward the incident part in the second direction along a direction away from the detection target in the first direction.

Abstract-CW-THz vector spectroscopy and imaging system based on 1.55-µm fiber-optics

Jae-Young Kim, Ho-Jin Song, Makoto Yaita, Akihiko Hirata, and Katsuhiro Ajito  »View Author Affiliations

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-22-2-1735

Optics Express, Vol. 22, Issue 2, pp. 1735-1741 (2014)
http://dx.doi.org/10.1364/OE.22.001735

We present a continuous-wave terahertz (THz) vector spectroscopy and imaging system based on a 1.5-µm fiber optic uni-traveling-carrier photodiode and InGaAs photo-conductive receiver. Using electro-optic (EO) phase modulators for THz phase control with shortened optical paths, the system achieves fast vector measurement with effective phase stabilization. Dynamic ranges of 100 dB·Hz and 75 dB·Hz at 300 GHz and 1 THz, and phase stability of 1.5° per minute are obtained. With the simultaneous measurement of absorbance and relative permittivity, we demonstrate non-destructive analyses of pharmaceutical cocrystals inside tablets within a few minutes.

© 2014 Optical Society of America

Abstract-Chemical Mapping of Pharmaceutical Cocrystals Using Terahertz Spectroscopic Imaging

http://pubs.acs.org/doi/abs/10.1021/ac302852n
Danielle M. Charron , Katsuhiro Ajito *, Jae-Young Kim , and Yuko Ueno 
NTT Microsystem Integration Laboratories, NTT Corporation

Terahertz (THz) spectroscopic imaging is a promising technique for distinguishing pharmaceuticals of similar molecular composition but differing crystal structures. Physicochemical properties, for instance bioavailability, are manipulated by altering a drug’s crystal structure through methods such as cocrystallization. Cocrystals are molecular complexes having crystal structures different from those of their pure components. A technique for identifying the two-dimensional distribution of these alternate forms is required. Here we present the first demonstration of THz spectroscopic imaging of cocrystals. THz spectra of caffeine–oxalic acid cocrystal measured at low temperature exhibit sharp peaks, enabling us to visualize the cocrystal distribution in nonuniform tablets. The cocrystal distribution was clearly identified using THz spectroscopic data, and the cocrystal concentration was calculated with 0.3–1.3% w/w error from the known total concentration. From this result, THz spectroscopy allows quantitative chemical mapping of cocrystals and offers researchers and drug developers a new analytical tool.