a
College of Optical Sciences, University of Arizona, 1620 East University Boulevard, Tucson, USA
E-mail: spau@optics.arizona.edu
;
Fax: +1 520-621-4358
;
Tel: +1 520-626-3908
b
Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koh-en, Kasuga-shi, Fukuoka 816-8580, Japan