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Chapter 19-20 1 Acoustic-optics & Electro-Optics 其实,也属于非线性光学.

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Presentation on theme: "Chapter 19-20 1 Acoustic-optics & Electro-Optics 其实,也属于非线性光学."— Presentation transcript:

1 Chapter 19-20 1 Acoustic-optics & Electro-Optics 其实,也属于非线性光学

2 Review

3 非线性的来源  理想模型的偏差  强场驱动下偏离谐振 子模型  电子云的畸变  等等

4 NONLINEAR OPTICAL MEDIA

5 The ‘P-E’ relation From Maxwell’s equations

6 The Nonlinear Wave Equation 但是,由于物质内部的屏蔽 作用,在可见光波段,非线 性响应非常小 … 低频时 (<MHz), 磁滞回线是种典 型的强非线性

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8 关注点  二次非线性  自聚焦  四波混频  孤子 (soliton)

9 SECOND-ORDER NONLINEAR OPTICS

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11 Second-Harmonic Generation (SHG) and Rectification

12 to maximize the SHG effìciency  the incident wave have the largest possible power P  by use of pulsed lasers with large peak power  be focused to the smallest possible area A  provide the longest possible interaction length L

13 Optical second-harmonic generation

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15 Electro-Optic Effect

16 其实,是 Three-Wave Mixing

17 Frequency and Phase Matching 全部由光子参与的过程,满足。。。

18 Three-Wave Mixing Modalities

19 Wave Mixing as a Photon Interaction Process

20 两大类可能性 可以动量匹配 不可以动量匹配

21 Non-Collinear SHG Spontaneous Parametric Downconversion (SPDC).

22 Generation of Entangled Photons  Parametric down-conversion (PDC)  twin daughter photons are produced simultaneously from a parent photon  the signal and idler photons have natural correlations in energy and momentum.  Type-I phase matching  The generated signal and idler photons have parallel polarizations.  Type-II phase matching  The signal and idler photons have perpendicular polarizations. 22

23 Generation of Entangled Photons 23 Parametric down-conversion (PDC)

24 in Collinear Three-Wave Mixing

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27 Tolerable Phase Mismatch and Coherence Length Lc: 几个微米 L<Lc 时(比如非线性晶体的粉末), 可以看到一些 SHG 信号

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31 Quasi-Phase Matching 对非线性感应系数 d 做周期调制

32 畴反转: n 不变, d  -d….

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47 THIRD-ORDER NONLINEAR OPTICS

48 Kerr medium

49 Thírd-Harmoníc Generatíon (THG) Optical Kerr Effect

50 Self-Phase Modulation Self-Focusing

51 Cross-Phase Modulation (XPM)

52 Four-Wave Mixing (FWM)

53 Optical Phase Conjugation (OPC) to exactly reverse the propagation direction and phase variation of a beam of light

54 Degenerate Four-Wave Mixing as a Form of Real-Time Holography

55 in wave Restoration E.exp(ikz)  E*.exp(-ikz) E.exp(ikz)  E.exp(-ikz)

56 COUPLED-WAVE THEORY OF THREE-WAVE MIXING

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58 Second-Harmonic Generation (SHG)

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60 Optical Frequency Conversion (OFC)

61 Optical Parametric Amplifier (OPA)

62 Optical Parametric Oscillator (OPO)

63 ANISOTROPIC NONLINEAR MEDIA

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67 OPTICAL SOLITONS

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69 Soliton on the Scott Russell Aqueduct on the Union Canal near Heriot-Watt University, 12 July 1995

70 色散 (dispersion) 与非线性 (nonlinearity) 的竞争 / 补偿

71 虽然存在非线性, 但 两个孤子之间 ” 表 面 ” 上不会影响对 方, 除了一个 ” 时间 差 ” 线性 & 无色散系统中, 一个波包会保存其形 状, 但这与孤子有本质 的不同

72 速度与振幅相关. 振幅越大, 速度越快.

73 a Gaussian pulse of width  0 with dispersion parameter  ”,

74 END

75 HomeWorks  Problems 19.1-1  Problems 20.1-3  Problems 20.1-5


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