Researchers at the University of Twente’s MESA+ Institute for Nanotechnology have created an optical amplifier doped with a rare earth ion.
Rare-Earth-Ion-Doped Optical Amplifiers
It is important to amplify optical signals in photonics uses. Semiconductor optical waveguide amplifiers suffer the effects of temporal and spatial gain pattering; although the gain per unit length is as high as 1000 dB/cm.
Er3+ doped fiber amplifiers mix good overall gain with small non-linearities and low noise, but this process is expensive and requires numerous meters of fiber thus making them inappropriate for on-chip applications.
The MESA+ researcher, Professor Markus Pollnau and his colleagues were able to enhance the waveguide amplifiers’ modal gain per unit length to ~ 1000 dB/cm. This enhancement was possible by engineering the geometry, concentration of the dopant, and the host material. KLu(WO4)2, KGd(WO4)2 and KY(WO4)2 which are a group of monoclinic potassium double tungstates, were utilized in this approach. These materials doped with Yb3+ ions have highest transition side views seen in dielectric materials.
The newly developed rare-earth-ion-doped amplifiers may allow lossless propagation in plasmonic nanostructures, and may give optical gain in nanotechnology devices like nanolasers and nanoamplifiers. They can be used as on-chip amplifiers for transmitting data in high-bit-rate at approximately 1 ìm of signal wavelengths.