Satoru Tsuchikawa, Misato Torii, Shigeaki Tsutsumi
Directional Characteristics of Near Infrared Light Reflected from Wood
Summary
A near infrared auto-goniophotometer was designed to acquire detailed information on optical characteristics
of a biological material which had a cellular structure, such as wood. The reflected light, which
originated from the irradiation of polarized near infrared light, was separated into an unpolarized and a
polarized component by using two polarizing filters. The standardized reflected intensities of each component
at various incident angles ? and observation angles ?, ?up(?, ?) and ?p(?, ?), were measured. Sitka
spruce samples with various thicknesses were used. The measurements showed that the directional characteristics
of the unpolarized component were affected significantly by the irradiation conditions and the
sample thickness. Particularly, these varied with the wavelength of incident light ?. This shows that the
directional characteristics models we proposed previously are reasonable. On the other hand, matrices
of the directional characteristics for polarized components typically show an elliptical shape which is
strongly affected by incident angle and only slightly by ?. Based on these results, the effects of sample
thickness on the spectral directional characteristics were determined.
Holzforschung, Walter de Gruyter
Print ISSN: 0018-3830
Volume: 55, 09/2001
Pages: 534 - 540
Show full article (external site)
Show all available items of this journal