Chirped Bragg Grating Waveguides Directly Written Inside Fused Silica Glass With an Externally Modulated Ultrashort Fiber Laser

A modulated fiber laser provided burst-trains of femtosecond pulses to directly write linearly chirped Bragg grating waveguides inside bulk fused silica glass in a single process step. The results represent the first demonstration of chirped gratings embedded in bulk glass with an ultrafast laser. Simple exposure controls offer facile means for tuning spectral and dispersion responses in three-dimensional optical circuits.