Femtosecond laser micromachining of Nd:GdCOB ridge waveguides for second harmonic generation

We report on the fabrication of Nd:GdCOB ridge waveguides by using femtosecond laser micromachining of planar waveguides that were produced by carbon ion irradiation. The guiding properties of the Nd:GdCOB ridge waveguides are investigated. The second harmonic generation (SHG) at 532 nm green laser from ridges in a series of transverse widths is realized. The results show that the optical conversion efficiencies of SHG in the fabricated ridge waveguides are considerably enhanced with respect to the planar waveguide, and the maximum value reaches 11.4% under a pulsed 1064 nm laser pump.

► First Nd:GdCOB ridge waveguides by ion irradiation and femtosecond laser ablation.
► Enhancement of second harmonics in Nd:GdCOB ridge waveguides to planar ones.
► Presentation of a new method to form ridge waveguides in nonlinear crystals.