Excited-state absorption spectroscopy of Nd3+:SrF2 crystals in the 1280 - 1320 nm spectral wavelength range

The excited-state absorption (ESA) in Nd3+:SrF2 crystals was investigated in the 1280 - 1320 nm spectral wavelength range by selective laser excitation. It was found that, on excitation at wavelengths of 743 and 800.5 nm, there is no ESA in the ranges 1304 - 1309 and 1295 - 1297 nm. Weak ESA bands are observed in the 1297 - 1304 and 1309 - 1320 nm ranges and the differential ESA cross section does not exceed 0.3 x 10-21 cm2 . The results indicate that the ESA does not preclude the use of an Nd3+:SrF2 crystal as the amplifying medium in the wavelength range 1280 - 1320 nm. (active media)