Sogang Univ Nonlinear Optics Lab Jun Hee Sun Optical Kerr Gate.

Presentation on theme: "Sogang Univ Nonlinear Optics Lab Jun Hee Sun Optical Kerr Gate."— Presentation transcript:

1 Sogang Univ Nonlinear Optics Lab Jun Hee Sun Optical Kerr Gate

2 optical Input 에 따른 매질의 굴절률의 변화가 생기는 현상 Pump beam Probe beam Kerr medium Polarizer Analyser Optical Kerr Effect Optical Kerr Gate

3 Kerr susceptibility NONLINEAR POLARIZATION

4 Pump beam Probe beam * 참고 1* Optical Kerr Effect in an isotropic medium

5 Pump beam 이 매질 내에 존재하는 상태에서 45 0 로 편광된 Probe beam 이 입사 되었을때 probe beam 의 x 방향과 y 방향으로 편극된 빛이 느끼는 Susceptibilyty 의 차이 위상차 L: 빛과물질사이의상호작용길이 Pump beam 에 의한 굴절률의 변화

6 Analyser 를 통과하여 편광 시킨 빛의 세기 최종적으로 검출되는 빛의 세기는 Probe beam 의 세기에 비례 하고 Pump beam 의 제곱에 비례한다, Kerr constant * 참고 2*

7 Experimental setup Kerr medium Photodiode Ti:Sapphire laser P1 P3 BS L2L1 Lock-in amp chopper P2 time delay

8  Ti:Sapphire laser : wavelength 800nm  repetition rate 82MHz  power 800mW  Beamsplitter : pump:probe=20:1  Pump : 4.88nJ, Probe : 0.24nJ  L1 : f=35mm BK7 Lens  L2 : f=70mm BK7 Lens  Polarizer1,2 : Glane laser polarizer  Polarizer3 : Glane taylor polarizer  Detector : Si Photodiode  Lock-in amplifier (THORLAB model: LIA100)

9 Pump beam Probe beam BS pol1 pol2 pol3 sample PD

10 Standard sample: CS 2 (carbon disulfide)  Pump Intensity :  Probe Intensity :  굴절률의 변화 :  Phase shift :  Detected Intensity : power : 800mW (Pump beam=400mW, Probe beam =20mW) repetition rate 82MHz, wavelength 800nm CS 2 : linear refractive index 1.62, kerr susceptibility : 10 -12 esu

11 Third-order nonlinear optical properties of didodecydimethlammonium-Au(dmit) 2 Shufeng Wang, Wentao Huang, Tieqiao Zhang, Hong Yang, Qihuang Gong, Yoshihito Okuma Masashi Horikiri, Yasuhiro F. Miura, Appl. Phys. Lett. 75, 1845 (1999)  Ti:sapphire laser ( wavelength 830nm repetition rate 76MHz)  pump:probe=8:1  sample:2C12-Au(1mm)  detector : photodiode  1.2mM : 1.0X10 -13 esu  1.8mM : 6.5X10 -13 esu  2.7mM : 4.7X10 -13 esu

12 Ultrafast optical Kerr effect of Ag-BaO composite thin films Q. F. Zhang, W. M. Liu, Z. Q. Xue, J. L. Wu, S. F. Wang, D. L. Wang, Q. H. Gong, Appl. Phys. Lett. 82, 958 (2003)  Ti:sapphire laser (wavelength 820nm power 24nJ, repetition rate 76MHz)  pump:probe=10:1  detector:photodiode  sample:Ag-BaO 300nm

13 * 참고 1* Isotoropic 한 매질에서 components ( isotropic) Optical Kerr Effect in an isotropic medium

14 * 참고 2* Third-order nonlinear optical coefficients of various materials Material n 0 n 2 (cm 2 /W) Crystal Al 2 O 3 1.8 2.2X10 -14 2.9X10 -16 GaAs 3.47 1.0X10 -10 3.3X10 -13 Si 3.4 2.0X10 -10 2.7X10 -14 Glasses BK-7 1.52 2.0X10 -10 3.4X10 -16 Nanoparticles CdSSe in glass 1.5 1.0X10 -12 1.8X10 -14 CS 3-68 in glass 1.5 1.3X10 -8 2.3X10 -10 Liquids Acetone 1.36 1.1X10 -13 2.4X10 -15 Benzene 1.5 6.8X10 -14 1.2X10 -15 CS 2 1.63 2.2X10 -12 3.2X10 -14 CCl 4 1.45 8.0X10 -14 1.5X10 -15

15  The Principle of Nonlinear Optics Shen  Nonlinear Optics Robert W. Boyd  Handbook of Nonlinear Optics Sutherland  비선형광학 이범구  미소 반도체 BiI 3 colloid 의 Optical Kerr 특성 박장은  Q. F. Zhang, W. M. Liu, Z. Q. Xue, J. L. Wu, S. F. Wang, D. L. Wang, Q. H. Gong, Appl. Phys. Lett. 82, 958 (2003)  Shufeng Wang, Wentao Huang, Tieqiao Zhang, Hong Yang, Qihuang Gong, Yoshihito Okuma, Masashi Horikiri, Yasuhiro F. Miura, Appl. Phys. Lett. 75, 1845 (1999) Reference