Spatial nonlinear optics anisotropy and directional growth of TbCOB crystal by micro-pulling-down for SHG application

Towards the spatial optimum phase matching (PM) crystal device through a novel way, the micro-pulling-down (mu-PD) technique was used for crystal growth along second-order harmonic generation (SHG) direction for the first time to the best of our knowledge. In this paper, the spatial distribution of I d(eff)vertical bar for a potential nonlinear optical (NLO) crystal TbCa4O(BO3)(3) (TbCOB) at 1064 nm was calculated and analyzed firstly, and the PM angle (113 degrees, 46 degrees) was found to possess the largest d(eff) value (type-I) being on the order of 1.39 pm/V. Along the optimum SHG direction, a rod-shape TbCOB crystal with 3 mm in diameter was successfully grown by using the mu-PD method. After simple cutting and polishing of the ends for mu-PD grown crystal, a high SHG efficiency (single-pass light reached up to 57%) was realized through a Nd:YAG pico-second laser at 1064 nm, which was comparable to that of crystal samples from Czochralski (Cz) growth. TbCOB crystals also exhibit a high laser damage threshold of > 15 GW/cm(2). (C) 2015 Elsevier B.V. All rights reserved.