Two-photon absorption spectra due to the valence excitons in CaF_(2) and BaF_(2) have been measured using the second harmonic of the output of a XeCl-excimer-laser pumped dye laser as a light source. The band gap energies of CaF_(2) and BaF_(2) are obtained as 11.8 and 10.6 eV at 298 K, respectively. The two-photon absorption coefficient β in the spectral region below the 2P exciton is expressed by an exponential function of the photon energy in both crystals. The values of β at the 2P exciton peak are about 2×10~(-9) cm/W for CaF_(2) and 3×10~(-9) cm/W for BaF_(2).
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