title: Improved phase hologram design for generating symmetric light spots and its application for laser writing of waveguides.
abstract: The improved method for calculation of a phase hologram and its application to laser writing of waveguides with a spatial light modulator are presented. It was found that the amplitude and phase distributions of light spots generated by a phase hologram can be distorted compared to those of a focused single beam. The distortion of light spots could be reduced by adding a simple constraint, in which light intensities around a light spot should be as small as possible, to the conventional calculation method of a phase hologram. It was also demonstrated that the improved calculation method can be considered essential for laser writing of waveguides.
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