Femtosecond laser fabrication of waveguides in DR13-doped PMMA

AbsctractThis work demonstrated the fabrication of tubular waveguides in bulk samples of PMMA doped with Disperse Red 13 (DR13) by oscillator only fs-laser micromachining. We studied the influence of the incident pulse energy on the diameter and quality of the fabricated waveguides by analyzing optical microscopy images. HeNe laser (632.8 nm) was coupled into the fabricated waveguides, revealing an annular intensity distribution resulting from the superposition of propagation modes with azimuthal symmetry. The averaged total loss of the fabricated waveguides was estimated as 0.8 dB/mm. Residual birefringence was observed in the produced waveguides, probably generated during the fabrication process, which prevented determining optically induced birefringence owing to the presence of the azochromophore DR13.