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We have demonstrated a diode-end-pumped continuous-wave and Q-switched Nd:GdVO4 red laser through intracavity frequency-doubling with a type-II phase-matched KTP crystal. The maximum CW output power at 671 nm was measured to be 505 mW at the incident pump power of 12 W, with the corresponding optical conversion efficiency of 4.2%. When the repetition frequency was 15 kHz, the maximum quasi-CW red output power was obtained to be 781 mW, with the corresponding optical conversion efficiency of 6.5%, the shortest pulse width of 65 ns, the highest pulse energy of 52 µJ and the highest peak power of 801 W.

Using the Czochralski method, Nd:GdVO4 single crystals have been successfully grown with polycrystalline materials synthesized by a liquid-phase method. Luminescence properties of these crystals are determined. The fluorescence lifetime of 0.52 at% Nd-doped GdVO4 crystal is 150 µs. Nd:GdVO4 crystal exhibits a concentration quenching effect. The Nd:GdVO4 crystal samples with different Nd concentrations were used in laser experiments at 1.34 µm pumped by a high-power laser diode (LD). This is the first time report that a laser with a power of up to 4.64 W at 1.34 µm has been achieved with a slope efficiency of 32.9%.

The thermal lensing effect generated in an end-pumped lightly doped Nd:GdVO4 crystal was found to be considerably weaker than that in Nd:YVO4 having the same Nd3+ concentration. Consequently, the laser performance of Nd:GdVO4 at high pump powers over 20 W was found to be superior to that of Nd:YVO4. TEM00 mode cw radiation of 14.3 W at 1.06 μm was achieved with an optical conversion efficiency of 55%, and average slope efficiency of 62%.

Nd-doped barium sodium niobate, (Ba2Na)1-x Nd x Nb5O15 (Nd:BNN), crystallizes with x=0.025 in a tetragonal system with a filled tungsten bronze structure and the point group 4 mm, conforming to the space group P4b m and z=2. The Curie temperature was 537±2°C. The lattice constants were a=b=1.2446(1) and c=0.3991(1) nm at room temperature. The measured absorption of Nd:BNN was compared to the Judd-Ofelt (JO) theory. When applied, the JO theory of parity-forbidden electric-dipole transitions of rare-earth ions on non-centrosymmetric sites demonstrates good agreement. An absorption band around 808 nm to match laser diode pumping is about three times broader than that of Nd-doped yttrium aluminum garnet crystal. The three intensity parameters Ω t were fitted as 5.677×10-20, 2.231×10-20, and 4.106×10-20 cm2 at t=2, 4 and 6, respectively. The fluorescence branch ratio at 1060 nm is 52.38%. The largest integrated emission cross section ∑(4 F 3/2→4 I 11/2) is 10.36×10-18 cm. These results indicate the crystal's potential applications as a practical laser material.

In this letter, we report the measurements of the polarization absorption spectra, polarization emission spectra and laser properties of Nd:GdVO4 crystal. The highest output power of up to 14.25 W at 1.06 µm has been achieved with a 4 mm thick Nd:GdVO4 crystal sample when it is pumped by a 26 W cw fiber-coupled laser diode array. The light-light conversion efficiency is 54.8%. The comparing laser experiments of Nd:GdVO4 with Nd:YVO4 are also carried out by using the same laser cavity.

In this paper, the neodymium-doped strontium fluorapatite crystal has been grown by the Czochralski method. The data of thermal expansion and specific heat of the crystal have been measured. The thermal expansion coefficients along X and Z direction are α1=11.4×10-6/K and α3=12.3×10-6/K respectively. The specific heat is 110 cal/mol·K at 330 K. The measured absorption spectra from 400 nm to 850 nm show that the crystal has absorption peaks around 805.5 nm, and the absorption coefficients at 805.5 nm are 16.05 cm-1 and 5.59 cm-1 for π and σ polarization respectively. The polarization fluorescence spectra at room temperature show that the strongest fluorescence is centered at 1058.8 nm. The lifetime of 4F3/2 is 175 µs for 1 at.% Nd3+ doped in the crystal. The laser at 1058.8 nm is demonstrated pumped by a 3W cw laser diode at 805.5 nm, and the slope efficiency is 31.7%.