Abstract

Recently, it has been demonstrated that by tightly focusing ultrashort laser pulses in the bulk of various glasses optical waveguides can be fabricated.^1,2 In this case the laser energy is deposited inside the material, leading to permanent refractive index modifications inside a small focal volume. When moving the sample with respect to the laser beam, optical waveguides can be generated. This technique allows to fabricate three-dimensional photonic structures in practically all transparent materials. Among the structures which have already been demonstrated are optical waveguides, ^1-4 beam splitters, ⁵ X-couplers, ⁶ directional couplers, ⁷ and stacked waveguides/ waveguide arrays.⁶

© 2002 Optical Society of America