Study On Rare Earth - Doped Lanthanum - Gallate Glass And Its Spectral Properties

Fiber communication, which was born from the invention and development of laser and optical fiber, have brought a great revolution to the world of communication history. It uses light wave as the carrier of information, optical fiber as transmission medium. But in the recent decades, due to the pursuit of information, the demand of the transmission rate and communication capacity of fiber communication is increasing rapidly. Because of the problems of cost, dispersion and signal crosstalk between channels that are caused by improving the single channel transmission rate and decreasing channel spacing, the optical amplifier which has the advantages of simple structure and low manufacturing cost is becoming the mainstream to solve the problem of transmission capacity by expanding the bandwidth of optical communication.The main object of this paper is to investigate the rare-earth doped lanthanum gallate glasses used for optical amplifier, all samples are prepared with the traditional melting method. The physical properties, raman spectrum, absorption spectrum and emission spectrum are measured. By use of Judd-Ofelt theory and least-squares fitting method, the the Judd–Ofelt intensity parameters ?t were determined, and some important radiative properties were calculated. Erbium doped sodium lanthanum gallium glass’ s 1550 nm transition(4I13/2 â†' 4I15/2) could be easily observed under 980 nm laser irradiation, The full-width at half-maximum(FWHM) bandwidth is 38 nm, the peak value of the stimulated emission cross section σe is ~7.29×10-21 cm2, the lifetime of the transition is 7.03 ms and the quantum efficiency is ~100%. Thulium doped potassium lanthanum gallium glass’ s lifetime of transition 3F4â†'3H6 and 3H5â†'3H6 are 1.89 ms and 2.44 ms theoretically. Thulium doped potassium lanthanum gallium glass’ s 1470 nm emission(3H4â†'3F4 transition) and blue(478nm) upconversion emission are obviously observed.