Effective segregation during Czochralski growth and spectral properties of Nd3+ in GSAG crystal

Abstract

GSAG and Nd:GSAG crystals were grown by standard Czochralski technique. The refractive index of GSAG in the wavelength range 500–3000nm, effective segregation coefficient and absorption cross sections of Nd3+ in GSAG were determined by optical absorption method. The effective segregation coefficient was calculated to be 0.525. The spectroscopic and laser properties of Nd:GSAG crystal were studied by Judd–Ofelt analysis. The Judd–Ofelt parameters were calculated to be Ω2=1.32×10−21cm2, Ω4=2.93×10−20cm2 and Ω6=3.91×10−20cm2. With these intensity parameters, the values of absorption and emission oscillator strengths, transition probabilities, fluorescence ratios and radiative lifetimes were obtained. The large fluorescence ratio of |[4F]3/2〉 is very favorable for laser operation at 942nm. These results confirm that Nd:GSAG is a suitable laser material for water vapor detection by DIAL.