Author Affiliations

H. -P. Chiang,^a,* Y. -C. Wang,^a P. T. Leung,^b and W. S. Tse^c

^aInstitute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan, R. O. C.

^bDepartment of Physics, Portland State University, P. O. Box 751, Portland, OR 97207-0751, U. S. A.

^cInstitute of Physics, Academia Sinica, Taipei, Taiwan, R. O. C.

^*Corresponding author: hpchiang@mail.ntou.edu.tw