Optical waveguides are of great importance to the telecommunications industry for the transmission and manipulation of data carried by optical pulses. We have recently demonstrated the capability to directly write waveguides into bulk glass using a femtosecond laser as shown in the photograph above. This ability to write waveguides and other photonic structures inside bulk glass is the first step toward realizing a photonic integrated circuit, the optical analog of electronic integrated circuits. A key advantage of our techniques for producing photonic structures is that we can easily produce three-dimensional structures, unlike lithographic techniques, which are limited to two dimensions. The ability to integrate multiple optical and opto-electronic devices into a single optical medium could revolutionize the telecommunications and opto-electronics industries.