High-power, broadly tunable, and low-quantum-defect KGd1-xLux(WO4)2:Yb3+ channel waveguide lasers

In KGd1-xLux(WO4)2:Yb3+ channel waveguides grown onto KY(WO4)2 substrates by liquid phase epitaxy and microstructured by Ar+ beam etching, we produced 418 mW of continuous-wave output power at 1023 nm with a slope efficiency of 71% and a threshold of 40 mW of launched pump power at 981 nm. The degree of output coupling was 70%. By grating tuning in an extended cavity and pumping at 930 nm, we demonstrated laser operation from 980 nm to 1045 nm. When pumping at 973 nm, lasing at 980 nm with a record-low quantum defect of 0.7% was achieved

Fabrication of low optical losses Al2O3 layer used for Er3+-doped integrated optical amplifiers

Al2O3 is commonly used as host material for Er3+-doped integrated optical amplifiers. In this paper, a Graeco-Latin square is used in DC reactive magnetron sputtering deposition experiment in order to get low optical losses Al2O3 layer. By reasonable selection and careful arrangement of experimental parameters, an optimal combination of deposition parameters is obtained via statistic analysis with the fewest experimental runs. The result forms the base for the further fabrication of Er3+-doped Al2O3 layer. The Graeco-Latin square experiment can also be used to investigate the influence of each parameter on the deposition rate of Al2O3 layer

Silicon oxynitride in integrated optics

A review on the state of the art of silicon oxynitride deposition at the MESA Research Institute will be given. The recent progress in the application of silicon oxynitride in communication devices will be discusse

Integrated Al2O3:Er3+ zero-loss optical amplifier and power splitter with 40 nm bandwidth

A combined planar lossless optical amplifier and 1x2 power splitter device has been realized in Al2O3:Er3+ on silicon. Net internal gain was measured over a wavelength range of 40 nm across the complete telecom -band (1525–1565 nm). Calculations predict net gain in a combined amplifier and 1x4 power splitter device over the same wavelength range for a total injected pump power as low as 30 mW

Improved arrayed-waveguide-grating layout avoiding systematic phase errors

We present a detailed description of an improved arrayed-waveguide-grating (AWG) layout for both, low and high diffraction orders. The novel layout presents identical bends across the entire array; in this way systematic phase errors arising from different bends that are inherent to conventional AWG designs are completely eliminated. In addition, for high-order AWGs our design results in more than 50% reduction of the occupied area on the wafer. We present an experimental characterization of a low-order device fabricated according to this geometry. The device has a resolution of 5.5 nm, low intrinsic losses (< 2 dB) in the wavelength region of interest for the application, and is polarization insensitive over a wide spectral range of 215 nm

Monolithic integration of erbium-doped amplifiers with silicon-on-insulator waveguides

Monolithic integration of Al2O3:Er3+ amplifier technology with passive silicon-on-insulator waveguides is demonstrated. A signal enhancement of >7 dB at 1533 nm wavelength is obtained. The straightforward wafer-scale fabrication process, which includes reactive co-sputtering and subsequent reactive ion etching, allows for parallel integration of multiple amplifier and laser sections with silicon or other photonic circuits on a chip