Evanescent-field amplification in Nd3+-doped fluoride planar waveguide

Planar channel waveguides of rare-earth doped fluoride glass are demonstrated with single mode excitation and propagation losses below 3 dB/cm. The waveguide core was fabricated by Ag+-Na+ molten salt ion exchange process in a borosilicate glass (BGG31), and a Nd3+-doped ZBLAN glass was used as a cladding. A 0.45 dB signal amplification at 1.064 mu m was observed in the fabricated 1 cm long waveguide, and a 0.9 dB amplification is expected at the;emission peak (1.049 mu m). Modeling results show 2.5 dB/cm potential gain with the improvement in surface flatness of ZBLAN glass. (C) 1996 American Institute of Physics.