Digital waveguide adiabatic passage part 2: experiment.

Using a femtosecond laser writing technique, we fabricate and characterise three-waveguide digital adiabatic passage devices, with the central waveguide digitised into five discrete waveguidelets. Strongly asymmetric behaviour was observed, devices operated with high fidelity in the counter-intuitive scheme while strongly suppressing transmission in the intuitive. The low differential loss of the digital adiabatic passage designs potentially offers additional functionality for adiabatic passage based devices.

Single-wavelength fiber laser with 250 mW output power at 1.57 microm.

A novel single-wavelength fiber ring laser with 250 mW output power is reported. A double-clad polarization-maintaining erbium-ytterbium co-doped fiber was used in a unidirectional ring cavity as an active medium to eliminate spatial hole-burning effect in the cavity. The output of the laser was single-longitudinal mode.