设计了一种以新型两级集成光学声光可调谐滤波器(IAOTF)为调谐元件的环形腔单偏振输出可调谐掺铒光纤激光器,它具有结构简单、调谐方便、调谐速度快和调谐范围大的优点。在对该集成光学声光可调谐滤波器滤波特性进行分析的基础上,在忽略放大的自发辐射(ASE)和激发态吸收情况下,对该激光器的特性参量如线宽、输出功率、斜率效率、阈值抽运功率等进行了分析。当抽运功率为100mw,射频为175MHz时,激光器输出中心波长为1550nm,最大输出功率约6.34mw,斜率效率为7.19%,半峰全宽(FWHM)为0.1nm。当声波频率每改变0.1MHz时,激光器输出中心波长改变约为0.88nm,由于集成光学声光可调谐滤波器的滤波范围很大(当声波频率变化20MHz时,滤波范围为180nm),所以激光器的调谐范围仅取决于掺铒光纤的增益带宽。
A new-style single mode output tunable erbium-doped fiber ring laser employing advanced two-stage integrated acousto-optic tunable filter (IAOTF) is presented. It has simple structure and can be tuned conveniently, widely and rapidly by changing the acoustic frequency. Considering the conversion efficiency of this IAOTF and neglecting amplified spontaneous emission (ASE) and excited-state absorption (ESA), the characteristics of the laser such as line width, output power, slope efficiency, and threshold power are discussed. When pumping power is 100 mW and radio frequency (RF) is 175 MHz, the center wavelength of the laser is 1550 nm, output power peak is about 6.34 mW, slope efficiency is 7.19%, and output peak with a full width at half maximum (FWMH) of 0.1 nm is obtained, the tuned peak gap is about 0.88 nm when changed the acoustic frequency by 0.1 MHz. Because the tunable range of the IAOTF is wide (about 180 nm when acoustic frequency changes in 20 MHz), the tunable range of the laser is only decided by the gain bandwidth of the erbium-doped fiber.