Fabrication and analysis of fiber-integrated micro-optical switches

3D光子晶体可用于控制来自由III V族化合物半导体制成的有源区的辐射方向。这对于获得高效的光纤集成微型光开关是有用的。我们在三维光子晶体中制作了光波导，并观察了光束的传播。波长为1.15 μ m的光束沿着在3D光子晶体中形成的线缺陷传播。三维光子晶体是在周期性镂空的三角晶格二氧化硅衬底上，用射频偏压溅射法制备的a-Si/SiO_2多层膜交替叠层而成。凹坑直径为0.2 μ m，点阵间距为0.5 μ m，层厚为0.2 μ m，在对应于芯的某一区域省略了光刻图形的衬底上，用10个周期的a-Si/SiO_2多层膜叠层，形成垂直于表面的线缺陷。垂直于表面的透射率的测量结果表明，用于观察传播的1.15 μ m的波长是在对应于芯的一维（iD）周期性区域的通带和对应于包层的3D周期性区域的阻带中。测量结果与时域有限差分（FDTD）计算结果吻合良好。

3D photonic crystals are useful to control the direction of radiation from the active regions made of III V compound semiconductors. It is useful to obtain highly efficient fiber-integrated micro optical switches. We have fabricated optical waveguides in three-dimensional (3D) photonic crystals and observed propagation of light beams. Light beams with wavelengths of 1.15 mum propagate along the line defects formed in the 3D photonic crystals. The 3D photonic crystals consist of a-Si/SiO_2 multilayers laminated alternately by rf bias sputtering on a periodically hollowed silica substrate with a triangular lattice. The pit diameter is 0.2 p.m and the pitch of the lattice is 0.5 p.m. The thickness of each laminated layer is 0.2 p.m. Line defects are formed normal to the surface by laminating a-Si/SiO_2 multilayers with 10 periods on the substrate in which the corrugation patterns have been omitted in a certain area corresponding to the core. The measurements of transmittance normal to the surface show that the wavelength of 1.15 mum used in observation of propagation is in the passband for the one-dimensional (iD) periodic region corresponding to the core and in the stop band for the 3D periodic region corresponding to the cladding, respectively. Measurements show good agreement with finite-difference time-domain(FDTD) calculations.