Heavy-metal fluoride glass is well known for its high infrared transparency, especially in its most common composition ZrF4-BaF 2-LaF3-AlF3-NaF (ZBLAN), which makes it an attractive host for mid-infrared emitting rare-earth ions. The mid-infrared wavelength region is of particular interest for many applications like molecular spectroscopy, process monitoring and infrared countermeasures, which demand a robust, simple and cheap laser source. We recently demonstrated a Tm 3+:ZBLAN waveguide laser emitting at 1.9 m with a slope efficiency approaching 40% . The devi ce is based on novel laser-written depressed cladding waveguides with butt-coupled bulk mirrors. However to obtain a highly integrated and robust laser system a different approach to providing the resonator feedback must be applied. A significant innovation would be the integration of Bragg-gratings into the waveguide in the form of distributed feedback (DFB) or distributed Bragg reflector (DBR) structures, thereby resulting in a monolithic device with narrow line width output .