Growth, nonlinear optical and self-frequency-doubled properties of LaGdCOB and Nd:LaGdCOB single crystals

Abstract

High optical quality La0.09Gd0.91Ca4O(BO3)3 and Nd0.03La0.08Gd0.89Ca4O(BO3)3 crystals, grown by Czochralski (Cz) pulling method, were investigated for their nonlinear optical (NLO) and laser properties. These crystals were found to possess moderate birefringence (0.0320 at 1064 nm), wide transparency (320–2300 nm) and large effective nonlinear effects (deff ∼1.2 pm/V), which were suitable for green laser generation. The second-harmonic-generation (SHG) phase matching (PM) properties, including PM curve, deff, angular acceptance and walk-off angle were investigated. Both of the calculations and experiments have indicated that the 1064 nm optimum PM direction which has maximum deff (∼1.2 pm/V) and SHG conversion efficiency (57.1%) locate in the second octant, i.e. (113.5°, 48.6°). Pumped by the 0.8 μm AlGaAs laser diodes (LD), the self-frequency-doubling (SFD) performance of Nd0.03La0.08Gd0.89Ca4O(BO3)3 crystal was evaluated, where as much as 115 mW green light at 546 nm was obtained with a (113°, 48.9°)-cut, 6 mm long and uncoated Nd0.03La0.08Gd0.89Ca4O(BO3)3 sample.