Optical, spectroscopic, and thermo‐optical properties of Nd 2 O 3 ‐doped Ca BA l glasses

The Nd 3+ ‐doped CaO‐Al 2 O–B 2 O 3 ‐CaF 2 glasses were prepared by melt‐quenching technique and their optical, spectroscopic, and thermo‐optical properties were studied. The density and refractive index showed an increase with addition of Nd 2 O 3 at the expense of CaO. The electronic polarizability increases with Nd 2 O 3 concentration due to the increase in NBO . The absorption spectra present characteristic bands of Nd 3+ transitions from the ground state 4 I 9/2 to the various excited states. The luminescence spectra show Nd 3+ emission at ~880 nm ( 4 F 3/2 → 4 I 9/2 ) and ~1064 nm ( 4 F 3/2 → 4 I 11/2 ), which increases with Nd 2 O 3 up to 3 wt%. The experimental lifetime decreases when Nd 2 O 3 content increases, mainly due to the nonradiative processes of direct energy transfer between Nd 3+ ions (cross relaxation). Results of thermal coefficient of optical path length ( d S / d T ) for the Ca BA l glasses did not present significant changes with Nd 2 O 3 concentration. These with values are comparable to the Fused Silica, and lower than the values measured for the CAS and LSCAS glasses. The results point out this glass system as a good candidate to be used in the development of photonics devices.