High-speed low-loss waveguide writing in fused silica using UV femtosecond laser pulses

Since the first demonstration of the process in 1995, fused silica is a widely used material for direct femtosecond waveguide writing. However, the high exposure dose requirement requires a low writing speed, which limits potential applications. By using ultraviolet light at 343 nm with yet, comparably longer pulses (450 fs) than normally used, we demonstrate high-speed low-loss waveguide writing, at a rate, approximately 1,000 times faster than typically used writing parameters. The fabricated waveguides are single mode and feature low propagation losses in the range of 0.1-0.2 dB/cm. This novel writing regime makes waveguide writing in fused silica highly efficient, while providing high-quality waveguides.