Board-Level Three-Dimensional Optical Interconnects

We introduce here a simple method of integrating 45° total internal reflection micro-mirrors with polymer optical waveguides by an improved tilted beam photolithography on printed circuit boards to provide surface normal light coupling between waveguides and optoelectronic devices for optical interconnects. De-ionized water is used to couple ultraviolet beam through the waveguide core polymer layer at 45° angle during the photo exposure process. This technique is compatible with PCB manufacturing facility and suitable to large panel board-level manufacturing. The mirror slope is controlled accurately (within ± 1°) with high repeatability. The insertion loss of an uncoated micro-mirror is measured to be 1.6 dB. ©2009 Optical Society of America OCIS codes: (130.3120) Integrated optics devices; (120.4610) Optical fabrication; (130.5460) Polymer waveguides. References and links 1. A. V. Krishnamoorthy, and D. A. B. Miller, “Scaling optoelectronic-VLSI circuits into the 21st century: A technology roadmap,” IEEE J. Sel. Top. Quantum Electron. 2(1), 55–76 (2006). 2. J. W. Goodman, F. J. Leonberger, S.-Y. Kung, and R. A. Athale, “Optical interconnects for VLSI systems,” Proc. IEEE 72(7), 850–866 (1984). 3. M. Li, and S. J. Sheard, “Waveguide couplers using parallelogramic-shaped blazed gratings,” Opt. Commun. 109(3–4), 239–245 (1994). 4. J. T. Kim, B. C. Kim, M. Jeong, and M. Lee, “Fabrication of a micro-optical coupling structure by laser ablation,” J. Mater. Process. Technol. 146(2), 163–166 (2004). 5. L. Schares, J. A. Kash, F. E. Doany, C. L. Schow, C. Schuster, D. M. Kuchta, P. K. Pepeljugoski, J. M. Trewhella, C. W. Baks, R. A. John, L. Shan, Y. H. Kwark, R. A. Budd, P. Chiniwalla, F. R. Libsch, J. Rosner, C. K. Tsang, C. S. Patel, J. D. Schaub, R. Dangel, F. Horst, B. J. Offrein, D. Kucharski, D. Guckenberger, S. Hegde, H. Nyikal, C. Lin, A. Tandon, G. R. Trott, M. Nystrom, D. P. Bour, M. R. T. Tan, and D. W. Dolfi, “Terabus: terabit/second-class card-level optical interconnect technologies,” IEEE J. Sel. Top. Quantum Electron. 12(5), 1032–1044 (2006). 6. N. Herdrickx, J. V. Erps, G. V. Steenberge, H. Thienpont, and P. V. Daele, “Laser ablated micromirrors for printed circuit board integrated optical interconnections,” IEEE Photon. Technol. Lett. 19(11), 822–824 (2007). 7. S. Garner, S.-S. Lee, V. Chuyanov, A. Chen, A. Yacoubian, W. Steier, and L. Dalton, ““Three-dimensional integrated optics using polymers,” IEEE J. Quantum Electron. 35(8), 1146–1155 (1999). 8. S. Lehmacher, and A. Neyer, “Integration of polymer optical waveguides into printed circuit boards,” Electron. Lett. 36(12), 1052–1053 (2000). 9. L. Wang, X. Wang, W. Jiang, J. Choi, H. Bi, and R. T. Chen, “45° polymer-based total internal reflection coupling mirrors for fully embedded intraboard guided wave optical interconnects,” Appl. Phys. Lett. 87(14), 141110 (2005). 10. M. Kagami, A. Kawasaki, and H. Ito, “A polymer optical waveguide with out-of-plane branching mirrors for surface-normal optical interconnections,” J. Lightwave Technol. 19(12), 1949–1955 (2001). 11. A. L. Glebov, J. Roman, M. G. Lee, and K. Yokouchi, “Optical interconnect modules with fully integrated reflector mirrors,” IEEE Photon. Technol. Lett. 17(7), 1540–1542 (2005). 12. S. Han, I. Cho, S. Hwang, W. Lee, and S. Ahn, “A high-density two-dimensional parallel optical interconnection module,” IEEE Photon. Technol. Lett. 17(11), 2448–2450 (2005). 13. N. Hendrickx, J. Van Erps, E. Bosman, C. Debaes, H. Thienpont, and P. Van Daele, “Embedded micromirror inserts for optical printed circuit boards,” IEEE Photon. Technol. Lett. 20(20), 1727–1729 (2008). (C) 2009 OSA 22 June 2009 / Vol. 17, No. 13 / OPTICS EXPRESS 10514 #110285 $15.00 USD Received 20 Apr 2009; revised 27 May 2009; accepted 29 May 2009; published 8 Jun 2009 14. M. Moyniham, B. Sicard, and T. Ho, “etc., “Progress toward board-level Optical Interconnect technology,” Proc. SPIE 5731, 50–62 (2005). 15. T. Yoshimura, M. Miyazaki, Y. Miyamoto, N. Shimoda, A. Hori, and K. Asama, “Three-dimensional optical circuits consisting of waveguide films and optical z-connections,” J. Lightwave Technol. 24(11), 4345–4352 (2006). 16. K. Y. Hung, H. T. Hu, and F. G. Tseng, “A novel fabrication technology for smooth 3D inclined polymer microstructures with adjustable angles,” Proceedings of the International Conference on Solid Sate Sensors, Actuators and Microsystems, USA, 821–824 (2003). 17. F. Wang, F. Liu, A. Adibi, and R. Tummala, “A Simple Method to Fabricate 45° Polymer Micro-Mirrors for Three-Dimensional Board-Level Optical Interconnects”, The 90th OSA Annual meeting, Laser Science XXI, Optical Society of America, 8–12 (2006). 18. F. Wang, F. Liu, G. K. Chang, and A. Adibi, “Precision Measurements for Propagation Properties of High Definition Polymer Waveguides by Imaging of Scattered Light,” Opt. Eng. 47(2), 024602 (2008).