title: Fabrication of three-dimensional 1 x 4 splitter waveguides inside a glass substrate with spatially phase modulated laser beam.
abstract: Multiple light spots can be generated by modulating the spatial phase distribution of laser beam with a spatial light modulator (SLM). In this paper, we demonstrate the fabrication of three-dimensional 1 x 4 splitter waveguides inside a glass by focusing multiple light spots of femtosecond (fs) laser pulses, which can be controlled by switching spatial phase distributions on an SLM. In the conventional fs laser writing technique, a highly precise positioning of a substrate is essential for fabricating a branched waveguide in a splitter. Using the technique proposed in this paper, a continuously branched waveguide can be produced easily by translating a glass substrate only one time; therefore this technique can eliminate the need for a high precision in positioning of a substrate and save a fabrication time.
authors.affiliation: Kyoto University Office of Society-Academia Collaboration for Innovation, Kyoto 615-8520, Japan. msakakura@saci.kyoto-u.ac.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Sakakura
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sawano
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Shimotsuma
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Miura
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Hirao