title: Control of the cross-sectional shape of a hollow microchannel embedded in photostructurable glass by use of a femtosecond laser.
abstract: Theoretical and experimental investigations have been made of the three-dimensional microchannel fabrication of photostructurable glass by use of a femtosecond (fs) laser. Generally, a microchannel fabricated inside glass by the scanning focal spot of a fs laser perpendicular to the direction of laser propagation assumes an elliptical shape with a cross section of large aspect ratio. We demonstrate that one can greatly reduce the aspect ratio merely by inserting a slit, which is oriented parallel to the laser's scanning direction, before the focusing lens. Computer simulations show that a more symmetrical pattern is obtained in the vicinity of the focal point with the help of such a slit, owing essentially to a diffraction effect.
authors.affiliation: RIKEN, The Institute of Physical and Chemical Research, Hirosawa 2-1, Wako, Saitama 351-0198, Japan. ycheng@postman.riken.go.jp
authors.forename: Ya
authors.initials: Y
authors.lastname: Cheng
authors.forename: Koji
authors.initials: K
authors.lastname: Sugioka
authors.forename: Katsumi
authors.initials: K
authors.lastname: Midorikawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Masuda
authors.forename: Koichi
authors.initials: K
authors.lastname: Toyoda
authors.forename: Masako
authors.initials: M
authors.lastname: Kawachi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Shihoyama