DIEGO SILVERIO DA SILVA

DIEGO SILVERIO DA SILVA

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Double line waveguide amplifiers written by femtosecond laser irradiation in rare-earth doped germanate glasses
2020 - SILVA, DIEGO S. da; WETTER, NIKLAUS U.; KASSAB, LUCIANA R.P.; ROSSI, WAGNER de; ARAUJO, MARIANA S. de
We report the production of active double waveguides in Er/Yb doped GeO2-PbO glasses, by direct femtosecond laser writing. The glasses were produced using the melt-quenching technique and the active waveguides were written using 30 fs laser pulses, at 800 nm, with writing speed of 0.06 mm/s and pulse energy of 32 μJ. The photo-induced negative refractive index change was of 􀀀 7.4 � 10􀀀 3. The Er/Yb doped sample showed a relative gain (signal enhancement of 7.5 dB/cm, for 105 mW of 980 nm pump power. The relative gain compensates both, the propagation losses and the absorption losses, and a positive maximum internal gain of 4.6 dB/cm can be obtained at the signal wavelength of 1550 nm. The results obtained in present work demonstrate that Er/Yb glasses are promising materials for the fabrication of integrated amplifiers, lossless components and lasers based on germanate glasses.
Production of a microfluidic random laser using ultrashort laser pulses
2019 - WETTER, NIKLAUS U.; GOMES, ANTONIO A.; SILVA, DIEGO S. da; ROSSI, WAGNER de
A random rhodamine laser system is produced on board of a femtosecond laser machined microfluidic system. When pumped by a nanosecond pulsed laser beam at 532 nm, laser emission at 610 nm is observed together with the linewidth narrowing typical of random lasers. The system can be easily integrated as an optofluidic component into microfluidic circuits for assessment of optical parameters on board of the lab-on-chip.
Femtosecond laser-written double line waveguides in germanate and tellurite glasses
2018 - SILVA, DIEGO S. da; WETTER, NIKLAUS U.; ROSSI, WAGNER de; SAMAD, RICARDO E.; KASSAB, LUCIANA R.P.
The authors report the fabrication and characterization of passive waveguides in GeO2–PbO and TeO2–ZnO glasses written with a femtosecond laser delivering pulses with 3μJ, 30μJ and 80fs at 4kHz repetition rate. Permanent refractive index change at the focus of the laser beam was obtained and waveguides were formed by two closely spaced laser written lines, where the light guiding occurs between them. The refractive index change at 632 nm is around 10-4 . The value of the propagation losses was around 2.0 dB/cm. The output mode profiles indicate multimodal guiding behavior. Raman measurements show structural modification of the glassy network. The results show that these materials are potential candidates for passive waveguides applications as low-loss optical components.
Production and characterization of femtosecond laser-written double line waveguides in heavy metal oxide glasses
2018 - SILVA, DIEGO S. da; WETTER, NIKLAUS U.; ROSSI, WAGNER de; KASSAB, LUCIANA R.P.; SAMAD, RICARDO E.
We report the fabrication and characterization of double line waveguides directly written in tellurite and germanate glasses using a femtosecond laser delivering 30 mu J, 80 fs pulses at 4 kHz repetition rate. The double line waveguides produced presented internal losses inferior to 2.0 dB/cm. The output mode profile and the M-2 measurements indicate multimodal guiding behavior. A better beam quality for the GeO2 - Pbo waveguide was observed when compared with TeO2 - ZnO glass. Raman spectroscopy of the waveguides showed structural modification of the glassy network and indicates that a negative refractive index modification occurs at the focus of the laser beam, therefore allowing for light guiding in between two closely spaced laser written lines. The refractive index change at 632 nm is around 10(-4), and the structural changes in the laser focal region of the writing, evaluated by Raman spectroscopy, corroborated our findings that these materials are potential candidates for optical waveguides and passive components. To the best of our knowledge, the two double line configuration demonstrated in the present work was not reported before for germanate or tellurite glasses.
Production and characterization of Femtosecond laser-written waveguides in a tellurium-zinc glass
2016 - SILVA, DIEGO S. da S.; X, JONATA; ROSSI, WAGNER de; KASSAB, LUCIANA R.P.; WETTER, NIKLAUS U.