New double line architecture produced by fs laser irradiation in Nd3+ doped TeO2-ZnO glass for photonic applications

We report the fabrication and passive characterization of Nd
³⁺
doped TeO
₂
-ZnO glass with a new configuration of double waveguides, written with fs laser operating at 800 nm, delivering 30 fs pulses at 10kHz repetition rate. The two written lines that form the double waveguide are formed by several overlapping lines. Results of output mode profile, beam quality factor M
²
and refractive index change are presented as well as the parameters used for laser writing. Writing speed of 0.5 mm/s and pulse energy of 15 μJ demonstrated to be adequate parameters for writing. Refractive index changes of Δn = 1×10
^-5
and Δn = 1×10-4 were found at 632 nm for double waveguides written with 4 and 8 overlapping lines, respectively. The mode image results at the output of the waveguides showed a confined beam in agreement with multi transverse order mode. Beam quality factor results were the following: M
_y
= 24±3 and M
_x
= 14±3 at 632 nm. The glasses are produced with the melt quenching technique and the preliminary results demonstrated that they are promising materials for the fabrication of passive and active components for photonic applications.