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Chapter 07&08 & 09 & 10 1. PHOTONIC-CRYSTAL OPTICS  下几页列出重要的概念,需掌握.

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Presentation on theme: "Chapter 07&08 & 09 & 10 1. PHOTONIC-CRYSTAL OPTICS  下几页列出重要的概念,需掌握."— Presentation transcript:

1 Chapter 07&08 & 09 & 10 1

2 PHOTONIC-CRYSTAL OPTICS  下几页列出重要的概念,需掌握

3 WaVE Transfer Matrix

4 Scattering Matrix

5 Airy's formulas

6 Fabry-Perot Etalon

7 Bragg Grating

8 Bloch Modes

9 Chapter 8

10 Comments…why?...

11 Comments…integration circuits 在小空间里控制光场的传播,用于信息 交换及应用!

12 Photonic Crystals Metamaterials  From a similar consideration 尺寸更小,亚波长, <200nm

13 PLANAR-MIRROR WAVEGUIDES

14 Firstly, from ray optics…  Reflection by mirrors  Correct in microwave frequency

15 Why?... At microwave  Perfect electric conductor (PEC)  ε = ―   n=  j   |r|=1  Phase change: 0 or π (半 波损)  0: 边界场强极大  π: 边界场强为零

16 Periodicity  Discrete modes

17 Propagation Constants

18 Dispersion Relation 截止频率 f 0 。 f < f 0 ( 波长大时 ) 模式消失,无法传 播。在截止频率处,群速度为零,即慢光效应。

19 Group Velocity c c.cosθ 一种特殊的光学延迟线 θ  π/2, 越慢

20 Field Distributions 正交归一本征模式

21 Multimode Fields

22 Comments  m=1,2,3…  How about m=0?  Infinite field amplitude, not allowed  Cutoff size: d>d c = /2 But coaxial PEC waveguide supports m=0 TEM mode, which in non-cutoff!

23 PLANAR DIELECTRIC WAVEGUIDES

24 Comparing to Section 1 No longer PEC boundary conditions  With field outside the core  With non-zero/pi reflection phase Now Electromagnetic optics

25 Phase condition

26 Field Distributions … with EM boundary conditions!

27 Dispersion Relation

28 Dispersion…

29 Group Velocity Goos-Hänchen shift 当相位为常数时, v=c.cosθ

30 Goos-Hänchen shift  Usually… positive and very small, <0.05λ  Could be negative and with large value in left- handed metamaterials  Backward energy flux  Strong dispersion in LHM

31 GH shift can make a cavity nature_450_397

32 TWO-DIMENSIONAL WAVEGUIDES

33 Boundary Conditions

34 Applications

35 OPTICAL COUPLING IN WAVEGUIDES

36 Input Couplers 尽可能大的交叠积分

37 End-Fire configuration

38 Prism & Grating Side Couplers To match the wavevector  m …

39 FIBERS 圆柱对称二维光波导,选择性阅读

40

41

42 Vortex modes & Higher-OAM modes

43

44 Resonator  From waveguide  Spatial confinement of EM waves  select specific frequencies from a signal  To generate stronger EM field intensity  For applications that need strong EM field  Laser  Quantum Physics  ……

45 Examples

46 PLANAR-MIRROR RESONATORS

47 Resonator Modes Interference … standing wave …

48 Similar to 1D waveguides … Smaller d  larger  v f (uncertainty principle)

49 As Traveling waves Multiple interference…

50 Traveling-Wave Resonator 驻波的缺点:场强分布不均匀,例如 E~cos(kz) 。 Traveling wave? 场强均匀分布,优点 : 例如可以充分利用增 益介质等。

51 Fabry-Perot resonator

52 Method I

53 Methods II  E1 : E0 透射 +E3 反射; E3 : E1 反射;  E2 : E1 透射; E4 : E3 透射 E0E1 E2 E3 E4 Much simple Transfer Matrix Method exp(―jkd) 不要忘了相位项 exp(―jkd) !

54 r 不能为 1 Resonance  strong dispersion  smaller group velocity 多次反射减缓光的速度

55 Quality Factor Q Q 越大,共振越强,群速度越小: 空间上对光脉冲的挤压,增强能量密度

56 Off-Axis Resonator Modes A special design for optical delay purpose … because a longer optical path…

57 SPHERICAL-MIRROR RESONATORS

58 Ray Confinement

59 Resonator stability diagram

60 Two-Dimensional Rectangular Resonators

61 Circular Resonators and Whispering-Gallery Modes

62 Three-Dimensional Rectangular Cavity Resonators

63 MICRORESONATORS  Microresonators are resonators in which one or more of the spatial dimensions assumes the size of a few wavelengths of light or smaller.

64 Applications  To confine other elementary excitations  Electrons, Polaritons, ions…  To enhance the interaction of photons with excitations  To enhance the quantum phenomena of excitations  Especially when the size is comparable with the wavelength  Optical Integration circuits

65

66

67 2012 10 月 19 日 Science

68

69 Comment  Size of resonator  Usually a minimum of λ/2  Smaller size d?  From 2dk=2mπ, k=n2π/ λ, one can use a medium with larger n value  To λ/2n

70 Other possibility?  Metamaterial with negative n L  n L d L +n R d R =mλ/2  Solution of m=0 is possible  d L =―n R d R /n L  两个厚度成正比关系,可以缩 放  腔的厚度可以做的尽可能的小

71 END

72 Homework 07  EXERCISE 7.1-1  解释什么是 Omnidirectional Reflection 。 我们日常生活中用的镜子是不是 Omnidirectional Reflection ? 为什么?

73 Homework 08  解释方程 8.2-25 每一项的物理意义。  Problems 8.2-6

74 Homework 10  EXERCISE 10.1-1  Problem 10.1-7


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