一、光学显微镜光学基础 眼见为实 Seeing is believing 100μm 1
一、光学显微镜光学基础 1 眼见为实 Seeing is believing
Frequency in Wavelength cycles per second in nm 106- m 400- 1020- Gamma rays Violet One angstrom 10 450 Indigo One nanometer Blue X-rays 500- Ultravioler Green 105 One micrometer Visible Light Yellow 10 Infrared 6003 Orange 子 One centimeter 00 Red 1010- Short radio waves One meter Short radio waves 109 750 手机 Broadcast band One kilometer 105 Visible Light:~6000 A 10 Long radio waves X-rays: λ0.5-2.5A Electrons: λ~0.05A
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Optical Imaging 3 Energy-Loss Processes Spectra (real space) (energy absorbtion) Elastic Inelastic Scattering Scattering 2 Diffraction 4 Secondary Spectra Signals (reciprocal space) (excitation processes) 1.Signal can be focused-real space image 3.Energy loss spectra (e.g.,OM,SEM,TEM) (due to absorption of incident radiation) 2.Scattering angles can be collected and 4.Secondary signals such as x-rays or analyzed in reciprocal space secondary electrons (e.g.,XRD or SAD) (due to excitation ofelectrons in material) (Figure from D.Brandon and W.Kaplan,Microstructural Characterization of Materials,2n Edition,Wiley (2008)p.6) 3
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XRD Vs OM XRD Optical microscope (OM) ·结构的信息 ·形貌的信息 晶体结构（相） -正空间(real space) - 晶格常数 ● 检查材料微观组织结构的 -应力/应变 最常用、最基础的手段 -倒易空间(reciprocal space) ·应用 ·形态的信息 一材料生产制造中的质量控制 一透视 一材料使用中失效原因分析 一探伤 一建立材料结构-性能关系
XRD vs OM XRD • 结构的信息 – 晶体结构(相) – 晶格常数 – 应力/应变 – 倒易空间(reciprocal space) • 形态的信息 – 透视 – 探伤 Optical microscope (OM) • 形貌的信息 – 正空间(real space) • 检查材料微观组织结构的 最常用、最基础的手段 • 应用 – 材料生产制造中的质量控制 – 材料使用中失效原因分析 – 建立材料结构-性能关系 4
一、光学基础 ·透镜成像与分辨率 ·显微镜光学系统 ·物镜的构造与技术（数值孔径、像差） ·CCD/CMOS电子影像系统
一、光学基础 • 透镜成像与分辨率 • 显微镜光学系统 • 物镜的构造与技术（数值孔径、像差） • CCD/CMOS电子影像系统
折射(refraction) n=1 n>1 n=1 折射率(refractive index ●Vacuum 1 .Air 1.0003 ●Vater 1.333 Incident wave Reflected ●Cytoplasm 1.35-1.38? wave 0 ● Glycerol 1.475 (anhydrous) Refractive index n,=1 ●Immersion oil 1.515 Speed =c 。Fused silica 1.46 .Optical glasses 1.5-1.9 Refractive index na Speed c/n Refracted wave Diamond 2.417 元/n+ Depends on wavelength and temperature →Snell'slaw: Mirror law: Sin(0)=n2 Sin(02) 6
折射(refraction) • 折射率(refractive index 6
色散(dispersion) ·不同波长光线的折射率n不同 http://gallery.hd.org/_c/natural-science/prism-and- refraction-of-light-into-rainbow-AJHD.jpg.html 7
色散 (dispersion) • 不同波长光线的折射率n不同 7
光学成像原理 Objective Lens” Focal length “Object Plane” “Image Plane” -u Magnified Light Object is placed image win 1 and 2fof Source the objective lens 1st image 1 and M=1 f 8
光学成像原理 8
Magnification in Compound Microscope (transmission illumination) Final image projected Condenser Objective onto a aperture aperture screen or Object Projector film (specimen) lens Objective lens First image Final image B ￠ Light Source Condenser lens vl v2 M=M,M,=出-)-) f Total mag.is product of mags.for each lens. 9
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日m b' 人眼所看到 Eye 的像 Eyepiece 目镜 b 九元汽气5气三艺三三 Fo Objective 物镜 ob Specimen 日◆
人眼所看到 的像 10 25 cm 物镜 目镜