Efficient diode-pumped Nd:KGd(WO4)2 laser grown by top nucleated floating crystal method

Abstract Diode pumping of a stress-free, Nd(5 at.%):KGd(WO4)2, grown by top nucleated floating crystal (TNFC) method, is presented. The diode-pumped laser was operated both in the free-running and passively Q-switched operating modes. Under optimized conditions of resonator and optics, the disk (1.3 mm in thickness), produced at room temperature an efficient free-running, TEM00 output with maximum power of 0.4 W, with 75% slope efficiency and 51% total laser efficiency. Under slightly different experimental conditions the laser was passively Q-switched by using Cr4+:YAG as saturable absorber. The passively Q-switched laser produced modulated pulses at average frequencies in the range of 10–20 kHz, with pulsewidth of ≈180 ns, with an average output power obtained was 30 mW at the maximum pumping power level. The results presented here indicate the potential Nd:KGd(WO4)2 crystals grown by TNFC growth method, as candidates for concentrated, stress free diode-pumped microlasers in a large variety of wavelengths, including the eye-safe range.