We have investigated the different optical properties such as confinement loss, waveguide dispersion of a five rings hexagonal photonic crystal fiber under varied air hole diameter (d), lattice pitch (Λ), and air hol...We have investigated the different optical properties such as confinement loss, waveguide dispersion of a five rings hexagonal photonic crystal fiber under varied air hole diameter (d), lattice pitch (Λ), and air hole diameter to lattice pitch ratio for three different materials fused quartz glass, borosilicate glass and sapphire glass. We observed low confinement loss and high negative dispersion at higher d/Λ. Achieving high d/Λ can be done in two ways: increasing the air hole diameter or decreasing the lattice pitch. It has been observed, increasing the air hole diameter has significant effect over reducing lattice pitch in achieving low confinement loss. On the other hand, decreasing the lattice pitch over increasing the air hole diameter has significant effect in achieving high negative dispersion. It has also been found that, effective refractive index (neff) decreases significantly when lattice pitch decreases.展开更多
文摘We have investigated the different optical properties such as confinement loss, waveguide dispersion of a five rings hexagonal photonic crystal fiber under varied air hole diameter (d), lattice pitch (Λ), and air hole diameter to lattice pitch ratio for three different materials fused quartz glass, borosilicate glass and sapphire glass. We observed low confinement loss and high negative dispersion at higher d/Λ. Achieving high d/Λ can be done in two ways: increasing the air hole diameter or decreasing the lattice pitch. It has been observed, increasing the air hole diameter has significant effect over reducing lattice pitch in achieving low confinement loss. On the other hand, decreasing the lattice pitch over increasing the air hole diameter has significant effect in achieving high negative dispersion. It has also been found that, effective refractive index (neff) decreases significantly when lattice pitch decreases.
文摘为了解决扫描探针显微镜(Scanning Probe Microscope,SPM)现有校准方法复杂程度高且存在局限性的问题,提出了一种基于二维标准微尺度正交栅格的SPM校准方法,通过对扫描获取的栅格图像进行互相关/卷积(Cross-correlation/Convolution,CC)滤波,实现对栅距中心坐标的峰值检测。校准的运动几何误差包括x轴和y轴位置偏差Δ_(x)和Δ_(y)、沿x轴和y轴扫描的直线度偏差δy和δx以及两轴之间的正交性偏差γ_(xy)。根据x轴和y轴扫描像素数、扫描范围、标准栅格计量检定节距平均值、栅距平均值计算得出校准因子C_(x)和C_(y)。采用标称节距为10μm的正交栅格样板对原子力显微镜(Atomic Force Microscope,AFM)进行校准实验,结果显示C_(x)和C_(y)分别为0.925和1.050,γ_(xy)为0.015°,该台AFM的校准扩展不确定度为0.33μm(k=2.56)。研究成果对于推动SPM校准标准文件的具体实施和执行具有积极意义,并为SPM仪器研制及性能评估提供了技术参考。
