Manuscript received July 14, 2007. C.-E. Lee, Y.-C. Lee, H.-C. Kuo, M.-R. Tsai, B. S. Cheng, T.-C. Lu, and S.-C. Wang are with the Department of Photonics, Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 300, Taiwan, R.O.C. C.-T. Kuo is with the Electronics-Opto Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan, R.O.C. (e-mail: hckuo@faculty.nctu.edu. tw). Digital Object Identifier 10.1109/LPT.2007.904998