基于光纤锥形滤波结构的波长可切换掺铥光纤激光器

Wavelength switchable thulium-doped fiber laser based on fiber-tapered filter structure

摘要:

本文提出了一种基于光纤双锥滤波结构的掺铥光纤激光器(thulium-doped fiber laser,TDFL)。首先,通过对单模光纤进行拉锥处理并级联为双锥结构,制备了光纤马赫-曾德尔干涉(Mach-Zehnder interferometer,MZI) 滤波器；随后,设计并搭建了泵浦波长为793 nm,增益介质长度为3.5 m的TDFL,激光器阈值为126 mW。实验中,通过调节偏振控制器(polarization controller,PC), 实现了1 830.6 — 1 881.7 nm范围内的单波长激光可切换输出,最小波长间隔为7.1 nm；在1 841.7—1 881.1 nm范围内实现了双波长激光可切换输出,最小及最大波长间隔分别为4.5nm和35.7nm。在20 min的监测时间内,激光器能够稳定输出单波长和双波长激光,功率波动分别小于0.52 dB和0.91 dB。本文提出的TDFL具有波长切换灵活的特点,在激光传感和测试等方面具有重要的应用价值。

Abstract:

A wavelength-switchable thulium-doped fiber laser (TDFL) based on a double fiber-tapered filter was proposed.Firstly,a Mach-Zehnder interferometer(MZI) filter was fabricated by cascading two fiber tapers produced by tapering single-mode fiber.Subsequently,a TDFL with a pump wavelength of 793 nm and a gain medium length of 3.5 m was designed and constructed,exhibiting a laser threshold of 126 mW.In the experiment,by adjusting the polarization controller (PC),a single-wavelength laser switching output within the range of 1 830.6—1 881.7 nm was achieved, with a minimum wavelength interval of 7.1 nm. Additionally,a dual-wavelength switchable laser output within the range of 1 841.7—1 881.1 nm was realized,with minimum and maximum wavelength intervals of 4.5 nm and 35.7 nm,respectively.During the 20 min monitoring period,the laser demonstrated stable single-and dual-wavelength outputs,with power fluctuations of less than 0.52 dB and 0.91 dB,respectively.The proposed TDFL exhibits flexible wavelength switching characteristics and holds significant application potential in laser sensing and measurement fields.