Er doped nanocrystalline ZnO planar waveguide structures for 1.55 mu m amplifier applications

Amplifying planar waveguide structures in Er-doped nanocrystalline II/VI se miconductor layer systems were developed by photolithography and wet chemic al etching. 2 mu m thick planar waveguides on glass substrates with lateral dimensions down to 5 mu m with rectangular cross section were realized. By optical excitation a maximum gain of 82 cm(-1) could be determined, which is sufficiently high to allow the design of compact planar amplifiers in th is material system. The influence of a thermal sintering step on the gain s pectrum and on the fluorescence lifetime has been investigated. By increasi ng the sintering temperature to 800 degrees C a consistent increase of gain and fluorescence lifetime was observed. (C) 1999 American Institute of Phy sics. [S0003-6951(99)03240-4].