TEMPERATURE DEPENDENCE OF NEGATIVE NONLINEAR ABSORPTION EFFECT IN AN ERBIUM-DOPED BORATE GLASS

The dependence of negative nonlinear absorption effect on sample temperature was investigated in erbium-doped borate glass, using an 810.0 nm laser diode. Reversed-phase waveforms were observed in the transmitted waveform in the temperature range of -200 to 750°C. The glass transition temperature was measured to be 708°C by differential thermal analysis. It is suggested that the effect can be obtained even when the glass is in the form of a supercooled liquid, because it is formed by optical transitions of the erbium ion inner shell.