Applied Physics Letters
All-optical inverter operating at 1.53 μm laser in erbium yttrium aluminum garnets
Yoshinobu Maeda
Abstract
An all-optical inverter derived from the negative nonlinear absorption effect was demonstrated in erbium–yttrium aluminum garnet crystals using 1.53 μm laser diode. The effect was obtained at wavelengths of 1532 to 1534 nm in absorption spectra corresponding to the transition from the I15/24 to the I13/24 levels in Er3+ for sample lengths greater than 1.0 mm. The reversed-phase transmitted wave forms were observed at modulation frequencies from 1 kHz to 1 GHz. The negative nonlinear absorption effect can be explained by considering an enhanced absorption model for a four-level system of the Er3+ ion.