Comparative study between conventional and diffusion-bonded Nd-doped vanadate crystals in the passively mode-locked operation

We design a reliable linear three-element cavity to make a comparative study between the conventional and diffusion-bonded Nd:GdVO₄ crystals in the passively mode-locked operation. Experimental investigations reveal that the mode-locked pulse width obtained with the diffusion-bonded crystal is considerably broader than that obtained with the conventional crystal, even though the diffusion-bonded crystal can significantly reduce the thermal effects. The pulse broadening is experimentally verified to come from the length of the undoped part that brings in a reduction of the spatial-hole-burning (SHB) effect.