一种宽带放大器用掺铒碲酸盐玻璃光纤的增益特性

研制了一种新型掺铒碲酸盐玻璃TeO2-ZnO-Na2O-Bi2O3,利用Judd-Ofelt和McCumber理论计算了Er3 离子的强度参数、自发辐射几率、吸收截面和发射截面等光谱参数.应用四能级粒子数速率-光功率传输方程模型,研究了以该掺铒碲酸盐玻璃光纤作为增益介质时光纤放大器的增益特性,模型综合考虑了Er3 离子的能量上转移、交叉驰豫、激发态吸收和放大自发辐射噪声.模拟结果显示,研制的碲酸盐玻璃光纤具有高的信号增益和宽的增益谱特性,在200 mW泵浦功率和多波长信号(-30 dBm× 56 channels)同时输入情形下,最大信号增益和20 dB增益带宽分别超过了40 dB和80 nm,增益谱覆盖了C L波段区域,预示这是一种较为理想的可用于宽带放大的增益介质.同时得出,碲酸盐玻璃光纤结构参数的选择对其增益特性具有重要影响.

Gain characteristics of a erbium-doped tellurite glass fiber applied for broadband amplification

A novel Er3+-doped tellurite glass with compositions of TeO2-ZnO-Na2O-Bi2O3 was prepared,and the intensity parameters,spontaneous emission probability,absorption and emission cross-section of Er3+ ions were calculated according to the Judd-Ofelt and McCumber theory. The signal gain characteristics of fiber amplifier with this erbium-doped tellurite glass fiber as a gain media were investigated based on a four-level population rate-light power propagation equation model pumped at wavelength of 1480 nm,in which energy up-conversion,cross relaxation,excited state absorption and amplified spontaneous emission noise of Er3+ions were considered. It is shown that the tellurite glass fiber prepared here presents a bigger signal gain and wider gain spectrum,its maximum signal gain and gain width at 20 dB exceeds 40 dB and 80 nm respectively,and its gain spectrum can across the C+L band region when pumped at 200 mW and injected with-30 dBm×56channels signal. The results indicate that the erbium-doped tellurite glass is a kind of better gain media which can be applied to broadband amplifiers. Moreover,the fiber structural parameters such as fiber length,fiber radius and relative index difference will have much affects on its gain characteristics.