可变晶格常数乙醇-二氧化硅胶质光子晶体中的Raman散射

制备了乙醇 二氧化硅三维胶质光子晶体，其晶格常数随着晶体高度的变化而变化.用皮秒 脉冲激光在不同高度激发光子晶体中乙醇产生Raman信号，得到了两个结果：1）即使Raman 信号的中心频率与光子晶体的带隙中心频率一致，在其禁带方向上测得的强度也没有被抑制 到与带隙深度同样的量级；2）尽管单纯的具有Raman信号频率的入射光的透过率随着高度的 变化而剧烈变化，但在光子晶体中产生的Raman信号强度却几乎不随高度的变化而变化，即 光子晶体的赝带隙几乎没有影响在禁带方向上测得的Raman信号强度.基于“光子晶体关键词：光子晶体Raman散射赝带隙内部光源

Raman scattering of ethanol solvent in a photonic crystal with a variational lattice constant

A silica colloidal photonic crystal in ethanol solution, whose lattice constant varies with the height of the crystal, was prepared. The Raman intensities of the ethanol solution induced by a picosecond intense laser were measured at different heights, and two phenomena were found: (1) although the frequency of Raman signals generated within the photonic crystal is equal to that of the photonic pseudogap of the photonic crystal, the Raman intensity attenuation measured is not reduced to the extent of that in the conventional transmission experiment; (2) although the transmission of an incident beam with the wavelength of the Raman signal is strongly dependent on the height of crystal, the intensity of the Raman scattering generated within the silica ethanol colloidal photonic crystal does not change with the height, i.e. it is insensitive to the pseudogap. These anti intuitive phenomena may be directly interpreted using the fact that the propagation mechanism of the monodirectional incidental laser is intrinsically different from that of the Raman signals from inner light sources inside a photonic crystal, and the Raman signals scattered by defects deep inside the crystal and generated in the surface layer contribute largely to the measured intensities.