Download presentation
Presentation is loading. Please wait.
Published byLeonard Teal Modified over 9 years ago
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
42
Vortex modes & Higher-OAM modes
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
67
2012 10 月 19 日 Science
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
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.