All-optical inverter operating over a temperature range of 15–1400 K in erbium-doped lutetium aluminum garnet

Abstract

An all-optical inverter, which operates over a range of 15–1400 K, was demonstrated in an erbium-doped lutetium aluminum garnet crystal with 787.3, 787.9 and 790 nm laser diodes. In the case of 787.3 nm, the reversed-phase wave forms were obtained in a temperature range of 15–1100 K. In the case of 787.9 and 790 nm, they were observed up to 1400 K. It has been confirmed that the negative nonlinear absorption effect can be explained by considering an enhanced absorption model for a five-level system of the Er3+ ion. The effect has a characteristic, which is almost independent of the ambient temperature because it is formed by optical transitions of the inner shell of the erbium atom.