著者

平位 和也 花田 啓明 木下 修一

出版者

社団法人 日本分光学会

雑誌

分光研究 = Journal of the spectroscopical research of Japan (ISSN:00387002)

巻号頁・発行日

vol.52, no.3, pp.157-165, 2003-06-15

参考文献数

15

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A new fluorescence-rejected Raman spectroscopy using frequency-domain four-wave-mixing is demonstrated. This method utilizes a broadband light pulse created by continuum generation as one of two pump pulses and a quasi-CW pulse with narrow bandwidth as a probe pulse. The resulting signal is spectrally analyzed by a monochromator-CCD detector combination. Owing to nonlinear character of this method with spatial discrimination of Raman signal from fluorescence, it is possible to measure Raman signal under fluorescent contamination, the limiting concentration of which is about 1, 000 times higher than that obtained by ordinary Raman spectroscopy.

著者

梅田 大樹 澁澤 栄 高柳 正夫 岡山 毅 平子 進一

出版者

The Spectroscopical Society of Japan

雑誌

分光研究 = Journal of the spectroscopical research of Japan (ISSN:00387002)

巻号頁・発行日

vol.55, no.4, pp.245-251, 2006-08-15

被引用文献数

1

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A new technique applying polarized near-infrared spectroscopy is proposed for precise measurements of moisture content in soil. Diffuse reflectance spectra of seven kinds of soil samples were measured. Linear relation between the moisture content and the signal intensity due to water is lost when the moisture content of the soil is high, presumably because intense direct reflection at the sample surface interferes measurements. Application of polarized light was found to improve the precision of quantitative measurement. In the scheme, by using a polariz-ing plate for each of the incident and reflected light, p-polarized light was irradiated on a soil sample, while only the s-polarized light from the sample was detected. The technique is expected to be applicable not only for precise measurements of moisture content but also for diagnosis of texture of soil with high concentration moisture.