Abstract

Heterodesmic crystals of Cr:CeSc₃(BO₃)₄ (CSB) with acentric trigonal structure have been shown to be high-effective active media for the solid-state lasers operating in the near infrared region. These crystals exhibit a broad-band luminescence with maximum at 900 nm, quantum efficiency of emission of about 90% at 300 K and high emission cross section. The quantum efficiency reduces by two times at 400 K. The luminescence lifetime is 40μ 300 K and 62 μs at 77 K. Non-radiative transition ⁴T₂ → ⁴A₂ is described in the Mott model with an activation energy E_nr = 2150 cm⁻¹ and frequency factor s_o = 1.4 10⁸ s⁻¹. Low value of the frequency factor is due to the weak promoting interaction. This property has been offered for the first time as an essential feature of heterodesmic crystals.

© 2002 Optical Society of America