本論文提出方向耦合器(Directional Coupler)與多模干涉耦合器(Multi-mode Interferometer)的設計流程與製程方式，藉以實現利用光學機制產生的力量驅動以及轉換微粒子移動的軌跡。光波導上的消逝波(Evanescent Wave)將可推動微粒子，而光學元件上之光場分佈將影響微粒子的驅動軌跡，藉以控制微粒子於光學元件上的位置。操作實驗使用50mW TM極化雷射光，以1540nm及1550nm波段用以選擇微粒子流動於不同出口。本論文以MATLAB軟體計算操縱微粒子的力量，並驗證力場分佈情形符合實驗結果。方向耦合器與多模干涉耦合器的耦合長度亦使用MATLAB計算，並於實驗中量測實際耦合長度。經過實驗證實，計算出的耦合長度與實驗結果相符，以此再次印證微粒子移動的軌跡將依隨光學元件上的光場分佈圖形。

In this thesis, we present the design and fabrication of directional couplers and multi-mode interferometers (MMI) for realizing micro-particle transport and switch through optical force. The evanescent field of the integrated photonic devices is able to propel a micro-particle to flow and control the trajectory of particle movement, according to the optical field distributed within the devices. By launching the TM polarized laser at the power of 50mW, the micro-particles can be transported to different output ports by selecting wavelengths between 1540nm and 1550nm. Optical force acting on the micro-particle is calculated by MATLAB, and the field of force is used for optical manipulation. Coupling lengths of directional coupler and MMI as a function of optical wavelengths are also analyzed by MATLAB and confirmed by experiments. It shows that the calculated coupling length agrees well with the results of experiments, where the trajectory of the micro-particle follows the optical interference pattern in the photonic device.

1. Jennifer E. Curtis, B.A.K., David G. Grier, Dynamic holographic optical tweezers. OPTICS COMMUNICATIONS, 15 June 2002. 207: p. 169-175.
2. Leach, J., et al., 3D manipulation of particles into crystal structures using holographic optical tweezers. Opt. Express, 2004. 12(1): p. 220-226.
3. Ashkin, A., et al., Observation of a single-beam gradient force optical trap for dielectric particles. Opt. Lett., 1986. 11(5): p. 288-290.
4. Sugiura, S.K.a.T., Movement of micrometer-sized particles in the evanescent field of a laser beam. OPTICS LETTERS, June 1, 1992. 17: p. 772-774.
5. Tani, S.K.a.T., Optically driven Mie particles in an evanescent field along a channeled waveguide. OPTICS LETTERS, November 1, 1996. 21: p. 1768-1770.
6. Lin, S., E. Schonbrun, and K. Crozier, Optical Manipulation with Planar Silicon Microring Resonators. Nano Letters, 2010. 10(7): p. 2408-2411.
7. Yang, A.H.J. and D. Erickson, Optofluidic ring resonator switch for optical particle transport. Lab on a Chip, 2010. 10(6): p. 769-774.
8. Grujic, K., et al., Sorting of polystyrene microspheres using a Y-branched optical waveguide. Opt. Express, 2005. 13(1): p. 1-7.
9. Ahluwalia, B.S., et al., Integrated platform based on high refractive index contrast waveguide for optical guiding and sorting. 2010: p. 76130R-76130R.
10. Blanco, F.J., et al., Microfluidic-optical integrated CMOS compatible devices for label-free biochemical sensing. Journal of Micromechanics and Microengineering, 2006. 16(5): p. 1006.
11. Helleso, O.G., et al., Surface transport and stable trapping of particles and cells by an optical waveguide loop. Lab on a Chip, 2012. 12(18): p. 3436-3440.
12. Cai, H. and A.W. Poon, Optical manipulation and transport of microparticles on silicon nitride microring-resonator-based add?drop devices. Opt. Lett., 2010. 35(17): p. 2855-2857.
13. Gaugiran, S., et al., Polarization and particle size dependence of radiative forces on small metallic particles in evanescent optical fields. Evidences for either repulsive or attractive gradient forces. Opt. Express, 2007. 15(13): p. 8146-8156.
14. Schmidt, B.S., et al., Optofluidic trapping and transport on solid core waveguides within a microfluidic device. Opt. Express, 2007. 15(22): p. 14322-14334.
15. Jalali, B.D.o.E.E., California Univ., Los Angeles, CA Silicon Photonics. Journal of Lightwave Technology, 2006. 24(12): p. 4600 - 4615
16. Soref, R.A.R.L., Hanscom AFB, MA Schmidtchen, J. ; Petermann, K. , Large Single-Mode Rib Waveguides in GeSi-Si and Si-on-SO2. IEEE Journal of Quantum Electronics, 1991. 27(8): p. 1971 - 1974
17. Marcatili, E.A.J., Slab-coupled waveguides. Bell Syst. Tech. Journal, 1974. 53: p. 645-674.
18. Petermann, K., Properties of optical rib-guides with large cross-section. Archivfur Electronik und Vbertrugungstechnik, (Germany), 1976. 30: p. 139-140.
19. Friedrich, L., et al., Directional coupler device using a three-dimensional waveguide structure. OPTICS COMMUNICATIONS, 1997. 137(4–6): p. 239-243.
20. Haus, H.A., W.P. Huang, and A.W. Snyder, Coupled-mode formulations. Opt. Lett., 1989. 14(21): p. 1222-1224.
21. Cheng, H.C.D.o.E.E., Florida Univ., Gainesville, FL, USA Determination of the coupling length in directional couplers from spectral response Photonics Technology Letters, IEEE, 1990. 2(11): p. 823 - 825
22. Soldano, L.B.D.o.E.E., Delft Univ. of Technol. Pennings, E.C.M. , Optical multi-mode interference devices based on self-imaging: principles and applications Journal of Lightwave Technology, 1995. 13(4): p. 615 - 627
23. Bachmann, M., P.A. Besse, and H. Melchior, General self-imaging properties in N × N multimode interference couplers including phase relations. Appl. Opt., 1994. 33(18): p. 3905-3911.
24. Chaumet, P.C. and M. Nieto-Vesperinas, Time-averaged total force on a dipolar sphere in an electromagnetic field. Opt. Lett., 2000. 25(15): p. 1065-1067.
25. Ruiz-Cortés, V. and J.P. Vite-Frías, Lensless optical manipulation with an evanescent field. Opt. Express, 2008. 16(9): p. 6600-6608.
26. Brevik, I., Experiments in phenomenological electrodynamics and the electromagnetic energy-momentum tensor. Physics Reports, 1979. 52(3): p. 133-201.
27. Marchington, R.F., et al., Optical deflection and sorting of microparticles in a near-field optical geometry. Opt. Express, 2008. 16(6): p. 3712-3726.
28. Gaugiran, S., et al., Optical manipulation of microparticles and cells on silicon nitride waveguides. Opt. Express, 2005. 13(18): p. 6956-6963.
29. Richardson, D.O.S.C., Arizona Univ., Tucson, AZ Gibbs, H.M. ; Koch, S.W. , Computer simulations of fully cascadable picosecond all-optical logic using nonlinear semiconductor etalons IEEE Journal of Quantum Electronics, 1991. 27(3): p. 804 - 808