Title :
Femtosecond-Laser Microstructuring of Ribs on Active (Yb,Nb):RTP/RTP Planar Waveguides
Author :
Cugat, J. ; De la Cruz, A. Ruiz ; Solé, R. ; Ferrer, A. ; Carvajal, J.J. ; Mateos, X. ; Massons, J. ; Solís, J. ; Lifante, G. ; Díaz, F. ; Aguilgo, M.
Author_Institution :
Fis. i Cristal.logafia de Mater. i Nanomater., Univ. Rovira i Virgili, Tarragona, Spain
Abstract :
We have produced rib waveguides by femtosecond-laser structuring of active (Yb,Nb):RbTiOPO4/RbTiOPO4 epitaxial layers. The ribs were produced by the approximation scanning technique combined with beam multiplexing. The so-obtained waveguides are trapezoidal in shape and show propagation losses with an upper bound of ~4 dB/cm. A simulation of the rib waveguides with real geometry parameters reveals high levels of light confinement at 632 and 972 nm. The near-field patterns of the fundamental modes have been obtained by exciting the waveguides at wavelengths of 632 and 972 nm. Micro-Raman spectroscopy study reveals that the damage to the crystalline structure in the rib boundaries, showing no amorphization traces, is around 3 μm in length and depth, which is significantly shorter than the total width of the ribs.
Keywords :
adaptive optics; epitaxial layers; high-speed optical techniques; laser materials processing; light propagation; micro-optics; niobium; optical losses; optical planar waveguides; rib waveguides; rubidium compounds; ytterbium; RbTiOPO4-RbTiOPO4:Yb,Nb; active epitaxial layers; active planar waveguides; approximation scanning technique; beam multiplexing; crystalline structure; femtosecond-laser microstructuring; fundamental modes; geometry parameters; light confinement; microRaman spectroscopy; near-field patterns; propagation loss; rib boundaries; rib waveguides; wavelength 632 nm; wavelength 972 nm; Laser beams; Microscopy; Multiplexing; Optical waveguides; Propagation losses; Ribs; Waveguide lasers; Femtosecond-laser microstructuring; nonlinear optical crystals; waveguides;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2012.2230615
