Periodic Photonic Structure: A New Frontier in Modern Optics. Ren Liyong

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1 Periodic Photonic Structure: A New Frontier in Modern Optics Ren Liyong 任立勇 Tsuru High School Sept. 9, 2008

2 Acknowledgement (JSPS) Dep. of Electronic Engineering Prof. Yasuo Tomita 中国科学院西安光学精密機械研究所 Xi an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences

3 Where I come from?

4 An ancient city---xi an Big Wild Goose Pagoda Built in 652, Tang Bell Tower Built in 1384, Ming Ancient City Wall Initially built in Tang, enlarged in 1370, Ming Drum Tower Built in 1380, Ming

Qin Terra-cotta Warriors and Horses Museum Qin Dynasty (211-206 BC) Warriors and

5 Qin Terra-cotta Warriors and Horses Museum Qin Dynasty ( BC) Warriors and horses built in 210 BC, is the underground army to protect the tomb of the first Emperor of the Qin Dynasty. It symbolizes that Qin Shihuang is the absolute ruler even he lay down underground. It was uncovered in 1947 when a farmer dig a well.

6 Self-introduction Education experience March 2001-March 2004 Ph. D of Engineering, Shanghai Institute of Optics and Fine Mechanics, CAS Sept June 2000 Master of Science, Xi an Institute of Optics and Precision Mechanics, CAS Sept June 1995 Bachelor of Science, Physics Department, Northwest University, Xi an Professional experience May 2007-Present JSPS Postdoctoral Fellow, University of Electro-Communications, Tokyo March 2004-April 2007 Associate Professor, Xi an Institute of Optics and Precision Mechanics, CAS July 1995-Feb College Physics Teacher, Physics Department, Northwest University, Xi`an

7 Outline of the talk History of information transmission Light and laser Magic information carrier: photon Periodic photonic structures for light controlling Fabrication methods of periodic photonic structures Revolutionary challenges to old topics Summary

8 How to transmit information 1837, telegraph Smoke Letter send line receive James Clerk Maxwell EM Theory 1876 Bell, telephone microphone earphone Radio TV

9 Mobile communication Station Station Station

10 Long history about material Material Mechanical Electrical Optical Stone Age, Iron Age, Till today Steel, Ceramics, Plastic Last century Everywhere around us Semiconductor Large scale integration Last several decades Glass lens Optical crystal Optic-fiber (1960) LSI What else?

11 Outline of the talk History of information transmission Light and laser Magic information carrier: photons Periodic photonic structures for light controlling Fabrication methods of periodic photonic structures Revolutionary challenges to old topics Summary

12 Light and laser

13 Difference between light and laser Natural light Excited atoms normally emit light spontaneously Photons are uncorrelated and independent Incoherent light E2 2 hν =E2-E1 E1 1

14 Difference between light and laser Laser Forced by the incident wave, the emission of any atom adds in phase to that of the incoming wave and in the same direction Photons are correlated and identical Coherent light E2 2 hν =E2-E1? hν =E2-E1 hν =E2-E1 1 E1

Amplification by the Stimulated Emission of Radiation

15 A magic light:laserunbeatable information carrier 1960 First Laser Obtained LASER stands for Light Amplification by the Stimulated Emission of Radiation High Coherent Monochrome Direction Brightness Be careful! I am strong!

16 Outline of the talk History of information transmission Light and laser Magic information carrier: photon Periodic photonic structures for light controlling Fabrication methods of periodic photonic structures Revolutionary challenges to old topics Summary

17 Using light to transmit digital information Encode bits on a beam of light CW light Light pulse to optical fiber

18 A mystery from the 19th century Conductive material e r E e + + Mean propagation distance of electrons is very short.

19 A mystery from the 19th century Crystalline conductor (e.g. copper) e r E e Answer: 1 Mean propagation distance increases greatly electrons are waves, not just particles 2 waves in a periodic structure can propagate without scattering

$Electrons Photons Electronic Electrons Semiconductors Periodic array of atoms Optical Photons Named as photonic crystals Periodic variation of refractive$

20 Electrons Photons Electronic Electrons Semiconductors Periodic array of atoms Optical Photons Named as photonic crystals Periodic variation of refractive index a ε 1 ε 2 ε 1 ε 2 ε 1 ε 2 ε 1 ε 2 ε(x) = ε(x+a) Atomic length scale~å Control electron flow Length scale ~λ (μm) 1μm=10 4 Å Control EM wave propagation

21 How about in the photonic crystal λ a Plane wave for most λ, beams propagate through crystal without scattering...but for some λ (~ 2a), no light can propagate! So we can control light propagation

22 Light is limited in the cavity Help! Let me out!

23 No scattering! No! No! Light propagates where there is a defect. No!

24 Outline of the talk History of information transmission Light and laser Magic information carrier: photon Periodic photonic structures for light controlling Fabrication methods of periodic photonic structures Revolutionary challenges to old topics Summary

25 Periodic photonic structures in nature Structure color VS. pigment color Minerals Wings of a butterfly Sea mouse Peacock feather Reflection from those structures are strongly wavelength sensitive which makes the color. OPN, Feb, 2003

26 100% transmission at sharp bends defect defect S. Guo, PhD Dissertation, ODU, 2003

27 Beam splitter defect defect defect

28 Outline of the talk History of information transmission Light and laser Magic information carrier: photon Periodic photonic structures for light controlling Fabrication methods of periodic photonic structures Revolutionary challenges to old topics Summary

29 (1)Fabrication of photonic crystal fiber: stack and draw silica glass tube (cm s) fiber draw 100μm n 1 n 2 Traditional fiber n 1 (core)>n 2 (cladding) ~1 mm preform drawing down in furnace

30 (2) Electron beam lithography for making photonic crystal Micro gear pump Raith 150 e-beam system, Germany Precision<20nm Minimized surface roughness 1nm=10-9 m Nano-bridge University of Konstanz Germany

31 (3)Micro-fabrication with fs laser pulse [ S. Kawata et al., Nature 412, 697 (2001) ] laser λ=780nm resolution=120nm 2µm Micro-bull as small as a red blood cell 7µm pulse=150fs 1μm=10-6 m 1nm=10-9 m 1fs=10-15 s (3 hours to make)

32 Outline of the talk History of information transmission Light and laser Magic information carrier: photon Periodic photonic structures for light controlling Fabrication methods of periodic photonic structures Revolutionary challenges to old topics Summary

$refractive index$ core Guiding is

33 (1) Guide light in hollow-core fiber Traditional fiber Guiding is possible High refractive index core Guiding is not possible in air High refractive index cladding But in PCF 10µm 5µm Hollow-core PCF, R. F. Cregan et al., Science 285, 1537 (1999)

34 (2) Optical Pulse propagates ways: faster, slower even being stopped normal dispersive medium anomalous dispersive medium Light speed 300,000km/s in air slow light fast light R. W. Boyd and D. J. Gauthier, Slow and Fast Light, in Progress in Optics 43, 497 (2002).

35 Outline of the talk History of information transmission Light and laser Magic information carrier: photon Periodic photonic structures for light controlling Fabrication methods of periodic photonic structures Revolutionary challenges to old topics Summary

$edu/photons/ Information carrier electron photon Circuit electronic circuit photonic circuit Control electron flow light flow Periodic array of atoms refractive index Periodic$

36 From electronic circuit to photonic circuit Information carrier electron photon Circuit electronic circuit photonic circuit Control electron flow light flow Periodic array of atoms refractive index Periodic photonic structure offers a good ability for controlling light propagation, it has become a new frontier in modern optics

37 Nowadays, optics and photonics are at the stage that electronics experienced 30 years ago with the developments and integration of component parts into larger systems. If only were possible to make materials in which electromagnetic waves cannot propagate at certain frequencies, all kinds of almost-magical things would happen. Sir John Maddox, Nature (1990) To see large scale photonic integration in future, we have a long way to go. I will be very happy if you are interested in my talk. I am expecting more optical engineers can be produced from our class.

38 Thanks!

Ms. Monika Srivastava Doctoral Scholar, AMR Group of Dr. Anurag Srivastava ABV-IIITM, Gwalior

By Ms. Monika Srivastava Doctoral Scholar, AMR Group of Dr. Anurag Srivastava ABV-IIITM, Gwalior Unit 2 Laser acronym Laser Vs ordinary light Characteristics of lasers Different processes involved in lasers