Electroluminescent thin films for integrated optics applications

The suitability of GaN, erbium doped GaN and erbium and manganese doped Zn2Si0.5Ge0.5O4 (ZSG) for use in integrated optics applications has been evaluated. GaN and GaN:Er optical waveguides were fabricated using inductively coupled plasma etching, and the losses evaluated as a function of wavelength. The waveguides were found to have decreased loss with increasing wavelength, yielding a 4.1 dB/cm loss at 1.5 mum. ZSG:Mn electroluminescent devices were fabricated and shown to emit strongly in the red and green, depending on annealing conditions, using a DC electroluminescent device configuration. The same ZSG:Mn thin films were found to be useful in the fabrication of optical waveguides. The results of this work indicated ZSG thin films could have multiple functionalities in integrated optic systems and inspired the study of ZSG:Er. The ZSG:Er material system enabled the fabrication of waveguide optical amplifiers. The optically pumped ZSG:Er waveguide amplifiers were found to deliver a signal enhancement of over 13 dB and a net gain of almost 2 dB over a amplifier length of 4.7 cm. These results combined with the electroluminescent nature of ZSG shows promise for creating an altogether new type of optical amplifier, an electroluminescent waveguide optical amplifier, which would greatly reduce waveguide amplifier cost and size by eliminating the need for an optical pump.