利用1 cm 长铒镱共掺高掺杂磷酸盐玻璃光纤制成直线型短腔光纤激光器,获得单频窄线宽、较大功率的激光输出。测量了输出功率随激光器热沉温度变化的特性;激光器热沉温度控制在11 ℃时,斜率效率可达24%;抽运功率为415 mW时,输出功率可达79 mW。光谱测试显示在1534 nm单纵模工作,边模抑制比(SMSR)大于50 dB。用零差法测得线宽为4.5 kHz。用低精细度法布里-珀罗(F-P)干涉方法,测量了磷酸盐玻璃光纤的折射率和热光系数分别为1.5195和-5.4×10-6 ℃-1,并测得激光器在高抽运功率下斜率效率降低,输出功率呈亚线性上升的特性。对这一现象及其温度关系进行了定性分析和讨论。

A 1 cm Er/Yb codoped phosphate glass fiber is used to make a short linear cavity fiber laser to get single-frequency,narrow line width and large power output. Relation of the output power to heat sink temperature is measured. When the heat sink temperature is stabilized at 11 ℃,the slope efficiency is 24%;and its output power reaches 79 mW under pump power of 415 mW. The output spectrum shows single longitudinal mode operation at 1534 nm with side mode suppressing ratio (SMSR) above 50 dB. Homodyne measurement gives its line width as narrow as 4.5 kHz. By taking the glass fiber as medium of a low finesse Fabry-Perot (F-P) cavity,refractive index and optic-thermal coefficient of the phosphate glass fiber is measured to be 1.5195 in 1530-1550 nm band and -5.4×10-6℃-1. It is found that the slope efficiency decreases at higher pump power range and the output power increases sub-linearly. This phenomenon and its relation to temperature are discussed qualitatively.