Control of the spectral parameters of vanadate lasers

It is experimentally established that the luminescence spectra of Nd³⁺ ions at the ⁴F_3/2 – ⁴I_11/2 transition in Nd³⁺:YVO₄, Nd³⁺:GdVO₄, Nd³⁺:Gd_1-xY_xVO₄, and Nd³⁺:Sc_1-xY_xVO₄ vanadate crystals strongly depend on the recording and polarisation angles with respect to the crystallographic axes. Using these angular dependences of luminescence spectra, it is possible to control the gain coefficient for lasers based on vanadate crystals, create broad gain bands for pico- and femtoseconds lasers, and change radiation wavelengths. Efficient operation of a passively Q-switched laser based on a Nd³⁺:GdVO₄ crystal cut at an angle to the a axis (θ = 25°, φ = 0) is demonstrated for the first time.