掺镱光纤激光器温度特性分析

Analysis on Thermal Characteristic of Ytterbium-Doped Fiber Lasers

温度对于光纤激光器的影响是多方面的,着重对光纤吸收截面、发射截面及激光器激射波长的温度特性进行了深入的研究,更加精确、全面地描述温度对光纤激光器系统的影响。当温度变化时,掺镱光纤各子能级上的粒子数分布发生变化,从而导致相应的吸收截面和发射截面发生变化。通过拟合方法可以得到光纤吸收截面与温度的关系。并利用任意温度下,吸收截面与发射截面的特定关系式,得到发射截面在各温度点上的取值。进一步推导出了激射波长与工作温度、光纤长度、腔的损耗、掺杂浓度等系统参数的关系;并将不同工作温度下激射波长的计算结果与实验结果比较,得到两种方法下的相似结论。

Fiber lasers are impacted by temperature in various ways. This article studies on thermal characteristic of absorption cross section, luminescence cross section and lasing wavelength and describes the thermal impact on fiber lasers in details. As the temperature varies, the distribution of the particles in all sub energy levels changes, which makes the absorption cross section and luminescence cross section different. The relationship between temperature and absorption cross section is calculated by a fitting method. The luminescence cross section is the function of temperature and absorption cross section by which the luminescence cross section in different temperatures can be calculated. Relationships between lasing wavelength and temperature, fiber length, cavity loss, doping concentration are deducted. Furthermore, the article compares the numerical result of lasing wavelength under different temperatures with the experiment data, which match with each other well.