Temperature variation of near-infrared emission from Cr4+ in aluminate glass for broadband telecommunication

Temperature dependence of fluorescence spectra of Cr4+ in an aluminate glass in the range of 1.2–1.6 μm was investigated from 15 to 300 K. The emission spectra were broadband centered at about 1.3 μm, wider than 200 nm width. The emission intensity drastically increased with decreasing temperature and that of 15 K was 20 times larger than that of 300 K. The bandwidth and mean energy of the emission band changed very slightly with temperature. The emission of Cr4+ in the glass fiber is expected as a tunable laser source and a broadband amplifier for the wavelength-division-multiplexed telecommunication.