PHOTONICS DEVICES FOR OPTICAL COMMUNICATIONS

Femtosecond laser written channel waveguides
Optical communications are the basis for all the information technology developed so far. Several photonics devices, such as optical amplifiers, diode lasers, optical switches, etc., are key elements for such development. We have carried out research in S/C/L band optical amplifiers, with emphasis is on S-band (1400 nm - 1530 nm) amplifiers. TDFA, Raman, Parametric Amplifiers and Hybrid Amplifiers were developed and characterized.
Presently, our focus-devices are femtosecond laser written channel waveguides in different platforms, such as rare earth doped glasses, glass-ceramics or Lithium Fluoride Crystals, for optical amplification and other applications.


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Profile of a fs laser written waveguide
In an Er-doped germanate glass.
(da Silva et al, Opt Materials, 2011)

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Spatial profile of a waveguide written with fs-laser in sol-gel activated Er3+: SiO2-Ta2O5 glass ceramics
(Ferrari et al, J. Nanoscience and Nanotechnology, 2011)

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Top view - fluorescence images of fs written waveguides in LiF crystal under argon laser excitation at 457.9 nm; Middle view - white light image of one of the crystal’s side facet, and bottom view - fluorescence image of the same facet under blue light illumination.
(Chiamenti et al, J. Appl. Phys. 2014)


Advanced Concepts in Solar Cells
Efficient renewable energy based devices are of fundamental importance for modern society, with clean, efficient renewable energy technologies ready to compete head to head with oil, gas, coal and even nuclear energy. Renewable energy will play a dominant role as we look for ways to diversify our economy, restore our environment and secure our place in the new global economy. Several alternatives exist for solar cells, but with efficiencies no higher than around 50%. Therefore, a search for novel ideas that can overcome this efficiency barrier is being sought worldwide. In our laboratory, two of those ideas are being studied: upconversion and downconversion based solar cells and disordered materials based solar cells. In both cases, the aim is to enhance and harvest photon absorption from the solar spectrum.

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From Wang et al, Adv. Materials 2011.

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From Pratesi et al, Opt. Exp. 2013.