Lossless Beam Splitters Based on Rare-Earth Doped Fluoride Films

Phase I seeks to develop lossless beam splitters in a planar integrated optical waveguide form for optical signal processing. We propose to construct lossless beam splitters based on a planar integrated optical waveguide form for the applications at 1.55 um. The proposed device consists of a beam splitter part and an optical amplification part. The device will be built on Er-doped fluoride glass films deposited by a plasma enhanced chemical vapor deposition (PECVD) process. The resulting integrated lossless beam splitters will lower the system cost and simplify the optical signal processing system. Fluoride glasses are inherently superior compared to conventional silicate glasses for the luminescence of rare-earth ions. Fluoride glasses also compatible with large concentration of rare-earth ions. Plasma-enhanced CVD allows the growth of wide variety of materials at very low temperatures. This offers the opportunity to grow high optical quality fluoride glass films. The PECVD is suited for the fluoride glass films due to its large-area, low temperature, high growth rate, and low fabrication cost capabilities. Rare earth doped multicomponent fluoride glasses can be obtained by our innovative single liquid source approach. The resulted films should be readily adaptable for the fabrication of lossless beam splitters in planar waveguide-forms.