Bifunctional Nd:CaSrNb2O7 crystal: A potential self-frequency-doubling laser material candidate

Abstract

One of the convenient methods to obtain green laser is by self-frequency-doubling (SFD) technique, the key is the SFD laser crystal. In this article, a bulk single crystal of 3.34 at.% Nd:CaSrNb2O7 was successfully grown by Czochralski method at about 1481 °C. Its spectral and thermal properties were investigated. There is a broad and strong absorption band at around 804 nm, which is very suitable for AlGaAs laser diode pumping. The polarized emission spectra show large emission cross-sections and full width at half maximum at around 1068 nm, and the fluorescence lifetime is 202 μs? Moreover, the fluorescence quantum efficiency reaches to 98.6%. The long lifetime, large emission cross-section, and high fluorescence quantum efficiency of Nd:CaSrNb2O7 crystal indicate that it is easy to achieve laser oscillation. The second harmonic generation intensity of 3.34 at.% Nd:CaSrNb2O7 crystal is about 3 times that of KH2PO4, and phase matching can be realized in this crystal. All these results show that Nd:CaSrNb2O7 is a good bifunctional crystal, which possesses laser and nonlinear optical functions simultaneously, and also demonstrate that it is a promising SFD material.