Single-mode X couplers and three-dimensional waveguides are fabricated in transparent glasses by use of an unamplified femtosecond laser generating energies of up to 100 nJ. Changing fabrication parameters such as power and scanning speed permits creation of waveguides with a wide range of structures and refractive-index difference. Optical coherence tomography shows large refractive-index changes of up to ~10<sup>-2</sup> in the waveguides; these changes are consistent with guided mode analysis.
© 2001 Optical Society of America
(140.0140) Lasers and laser optics : Lasers and laser optics
(140.3390) Lasers and laser optics : Laser materials processing
(320.0320) Ultrafast optics : Ultrafast optics
(320.7160) Ultrafast optics : Ultrafast technology
Kaoru Minoshima, Andrew M. Kowalevicz, Ingmar Hartl, Erich P. Ippen, and James G. Fujimoto, "Photonic device fabrication in glass by use of nonlinear materials processing with a femtosecond laser oscillator," Opt. Lett. 26, 1516-1518 (2001)