Investugate the correlation between collagen fiber and photonic band gap structure by second order susceptibility

• Main Authors: Zong-Xian Liu, 劉宗憲
• Other Authors: Shi-Wei Chu
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/54935568402822050480

碩士 === 國立臺灣大學 === 物理研究所 === 99 === In the past, several researches revealed the wavelength-dependent in the χ(2) spectra of collagen fiber. In our lab, we have found that the χ(2) spectra of type I collagen (by Chien-Min Liu) exhibits apparent spectral oscillation. We wonder which level organization cause oscillation in our χ(2) spectrum of collagen fiber. In a collagen fiber, we assume that the layered structure is composed of the water and fibrils, which was similar to the PBG structure. From the theory of one-dimensional PBG, the oscillation appears in the transmittance and density of mode (DOM). Previous investigations found the intrinsic χ(2) is enhanced proportionally to the DOM in a periodical structure. If the frequency of fundamental is far away the resonance band, the intrinsic χ(2) coefficient would be nearly a constant; therefore, the χ(2) has the oscillating phenomenon as DOM . We simulated the transmittance and DOM based on various structural hierarchical levels in collagen fiber, and then compared their oscillating period with experimental data. We found the oscillation phenomenon in our experimental data originates from the level of fibril (consists of sub-fibril and water) and its band gap is close to the absorption band (227nm) of collagen.