Optical waveguides fabricated in Cr:LiSAF by femtosecond laser micromachining

TORCHIA, GUSTAVO A.; TORCHIA, GUSTAVO A.; BIASETTI, DEMIAN A.; BIASETTI, DEMIAN A.; DI LISCIA, EMILIANO J.; DI LISCIA, EMILIANO J.

OPTICAL MATERIALS

ELSEVIER SCIENCE BV

Año: 2017 vol. 73 p. 25 - 32

0925-3467

In this work we present the fabrication of double-track type II waveguides written in 1% doped Cr:LiSrAlF6 (Cr:LiSAF) crystal by femtosecond laser micromachining. We studied waveguides fabricated at energies from 1 to 7 mJ per pulse at writing speeds of 15e45 mm/s. We found good wave-guiding performancefor both, Transversal Magnetic (TM) and Transversal Electric (TE) polarization modes as well asacceptable losses according to the expected values addressed to technological applications. Also, weperformed a high-resolution m-luminescence waveguide cross-section mapping between the tracks, in order to identify possible spectral changes caused for active ions Cr3þ corresponding to the 4T2 /4A2 vibronic transition in the focal volume zone, due to induced anisotropic graded stress. Finally, their lifetimes were measured for bulk as well as for waveguide trapped ions. We found that for the range of parameters of ultra-short micromachining used, the Cr3þ ions embedded in the waveguides remainedspectroscopically unchanged compared with those observed in bulk material.