Femtosecond-laser-written Microstructured Waveguides in BK7 Glass.

There is a deficiency of low-loss microstructured waveguides that can be fabricated with a single laser-pass to minimize stress build-up, which can enable enhanced functionality and higher compactness for integrated optical devices. We demonstrate, for the first time, a series of multi-ring claddings each with a pair of cores in BK7 glass. Each waveguide was fabricated using only a single laser-pass at 1 MHz pulse repetition rate, 5 mm/s translation speed, 250 fs pulse width, over a set of pulse energies.

Widely tunable, high slope efficiency waveguide lasers in a Yb-doped glass chip operating at 1 μm.

Ultrafast laser inscribed waveguide lasers can lead to highly efficient and compact optical devices. This Letter reports an average lasing efficiency of 65%±2.5% from a multi-waveguide 2.