Tailoring Photonic Strength in Monolithic Macroporous Silica for Random Media
Tailoring Photonic Strength in Monolithic Macroporous Silica for Random Media
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DOI：
10.1143/jjap.43.5359
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发表时间：
2004-08
影响因子：
1.5
通讯作者：
S. Murai;K. Fujita;K. Nakanishi;K. Hirao
中科院分区：
文献类型：
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作者：
S. Murai;K. Fujita;K. Nakanishi;K. Hirao
一个系统的方法调谐无序介电介质的光子强度已被证明在单片二氧化硅（SiO2）与互连的大孔由溶胶-凝胶法制备。在含有四甲氧基硅烷、聚（乙二醇）（PEG）、乙酸和水的系统中获得大孔SiO2凝胶。当烷氧基硅烷的水解和缩聚过程中形成的相分离的瞬态结构通过溶胶-凝胶转变被化学冻结时，形成大孔结构。孔和骨架的大小，这是由相分离的相对速率的溶胶-凝胶转变，可以通过PEG含量控制。相干后向散射的测量，以及基于独立散射近似的理论计算，揭示了光在多孔SiO2中的传输平均自由程可以通过调节孔的密度和尺寸来调节。
A systematic method of tuning the photonic strength of disordered dielectric media has been demonstrated in monolithic silica (SiO2) with interconnected macropores prepared by the sol–gel method. Macroporous SiO2 gels are obtained in a system containing tetramethoxysilane, poly(ethylene glycol) (PEG), acetic acid, and water. The macroporous structure is formed when the transient structure of phase separation developed during the hydrolysis and polycondensation of alkoxysilane is chemically frozen-in by the sol–gel transition. The sizes of pores and skeletons, which are determined by the relative rate of phase separation to that of the sol–gel transition, can be controlled by the PEG content. The coherent backscattering measurement, together with the theoretical calculation based on the independent scattering approximation, reveals that the transport mean free path of light in the porous SiO2 can be tuned by adjusting the density and size of the pores.