矽核光纖的製備與光學特性量測 Silicon cored optical fibers – fabrication and optical characterization

1. 矽核光纖的製備與光學特性量測 • Silicon cored optical fibers • – fabrication and optical characterization • 報告人：王倫 教授 • lon@ntu.edu.tw • 2013-07-12

2. Acknowledgement • Coworkers: Yi-Chuan Tseng, Yan-Bo Huang Prof. Hsuen-Li Chen(Department of Material Science and Engineering) • Monthly discussion with the joint team members from Dr. Ching-Fuh Lin, Dr. Wing-Kit Choi and Dr. Chao-Hsin Wu. • This work is supported by International Collaboration Project with Peking University (Grant No. NTU-ICRP-102R7558) • .

3. Outline • Motivationand Prior Arts • Design and Fabrication • Experiment Results • Discussion • Summary

4. Motivation • Optical fibers are silica based for communication/sensing • Pros and Cons • Semiconductor devices -- Si based for electronics, III-V for light sources • Pros and Cons • Semiconductor fibers ?? • Many unknowns with expected pros and cons • Potential Applications • mid-Infrared • Nonlinear • Silicon photonics • Sensing Sand – abundant supply for making glass fibers and Si chips, a blessing from Heaven to whom we should be grateful.

5. Research Groups Worldwide • Southampton University • Clemson University • Pen. State University

6. Properties of Semiconductor Fibers • Optics • Size: a few microns depending on transmission or sensing • Low transmission loss • Crystalline, smooth interface or surface • Doping for light sources • Rare earth elements • Electronics • Size: microwire to nanowire • Good conductivity • Crystalline better than poly and amorphous • Doping for n- and p-type • E-O integration: 22nm node and below, placement, etc.

7. Prior Arts fabricated by using HPCVD carrier mobility 1.05 cm2/Vs vs. typical Si FET 10^4-10^5 cm2/Vs relatively easy in control on crystalline direction, roughness and diffusion. 11mm long, dia. 100um, core 5um loss 3dB/cm Pier J. A. Sazioet al, SouthamptonUniversity, Science Vol. 311 No. 1583 (2006)

8. Prior Arts fabricated by using molten core method fabricated by using CVD P. J. A. Sazioet al, Southampton university, OE Vol. 20 No.4 (2012) John Ballatoet al, Clemson university, OE Vol. 16 No.23 (2008) a few meter long, loss 5~7dB/cm

9. Prior Arts Toward useful junction based devices amorphous p-n junction OE conversion with a pulsed laser P. J. A. Sazioet al, Southampton university, Nature photonics, Vol. 6 No.174 (2012)

10. Well, Our Prior Arts Using conventional SMF as preform pure SiO2 micro fiber JLT Vol. 27 No.15 (2009) Uniqueness: several meters long with below nm surface roughness

11. Micro Coil Rings Spectrum of 2-ring Coil Resolution: 5pm A typical photograph of an MCR whose gaps between adjacent rings are controlled within 1.5 μm. FSR = 270pm

12. Experiment Resultsoptical microscope images Visual inspection c • Cross section of Si cored fiber • Lateral view of Si cored fiber • Lateral view of silicon core

13. Results and Discussion crystalline characterization B.L. Boyce et al., ActaMaterialia, vol. 58, pp. 439 (2010) Boundaries can be observed for a- and poly-Si when FE-SEM is used. Chil-ChyuanKuo, J. Russ. Laser Res., vol. 32, pp. 12 (2011)

14. Results and Discussion Raman characterization – to know possible causes for crystalline P. Hashemi et al, University of Tehran, Conference of Microelectronics, pp. 326 (2005)

15. Summary • Long Si-cored silica-clad fibers were made. • Their propagation losses were measured, and crystalline properties characterized.

16. Thanks for your attention! • Questions? • Dreams?