Refractive-index changes can be induced by filamentation of 800-nm, 1-kHz femtosecond laser pulses in silica glass. Two-dimensional translation of a 40-μm -long filament leads to the formation of a curved waveguide because of bending by the previously induced refractive-index change. The fabrication of 2-mm directional couplers to split the coupled beam into 1:1 at a wavelength of 632.8 nm is demonstrated. The realization of three-dimensional directional couplers and wavelength division in the output from the couplers is also demonstrated.
© 2003 Optical Society of America
(160.2750) Materials : Glass and other amorphous materials
(190.7110) Nonlinear optics : Ultrafast nonlinear optics
(230.7370) Optical devices : Waveguides
(260.5950) Physical optics : Self-focusing
(320.7110) Ultrafast optics : Ultrafast nonlinear optics
Wataru Watanabe, Taishi Asano, Kazuhiro Yamada, Kazuyoshi Itoh, and Junji Nishii, "Wavelength division with three-dimensional couplers fabricated by filamentation of femtosecond laser pulses," Opt. Lett. 28, 2491-2493 (2003)