CONICET | Buscador de Institutos y Recursos Humanos

Optical waveguides obtained by femtosecond laser writing has become an extended fabrication method due to the reduction on fabrication stages number and also the wide range of applied materials. [1]. In this way, exploring new optically active materials is an interesting goal to the waveguide fabrication method that it can offer large technological potential like new tunable lasers and other integrated photonics applications. In this work we have fabricated type II [2] waveguides in a 1% doped Cr:LiSAF crystal sample by femtosecond laser micromachining with energies from 1 to 3 μJ per pulse and with a writing speed from 15 to 45 μm/sec. We have characterized the optical wave guiding performance using and ?end-fire? coupling system. We found good wave guiding qualities for both TM and TE polarization modes as well as acceptable losses according to expected values considering technological applications. On the other hand, it was studied and measured the luminescence features of Cr+3 ion and its corresponding lifetime for 4T2 à 4A2 transition for bulk as well for waveguide in order to find any emission band spectral shift due to residual stress obtained during the writing process[3]. Considering the parameter used for the waveguide micromachining, the Cr3+ ions keep their spectroscopic properties unchanged compared with those measured at bulk. These results give rise to a great possibility to develop suitable integrated photonics devices by using the Cr:LiSAF samples studied in this work. Additionally, experimental waveguide cross section mapping with high spatial resolution by means of confocal micro-spectroscopy could be a key data for exploration in order to understand structural modification induced by the femtosecond laser pulses and its effects on types of polarization supported in the waveguides.