可调谐单纵模多波长光纤激光器的研究

为了实现对台阶高度和绝对距离等物理量的高精度干涉测量，采用在一个光纤激光器中构建多个激光谐振腔的方法，构建了能同时发出多波长激光的光纤激光器。每个激光谐振腔都利用掺铒光纤作为增益介质，利用光纤光栅作为波长选择元件，改变光纤光栅的布喇格波长，即可改变对应谐振腔的激光波长。各个激光谐振腔独立但部分重叠，在重叠区域利用光纤耦合器构成复合子腔，使每个激光谐振腔都是复合激光谐振腔，从而使每个激光谐振腔都发出单纵模激光。结果表明，该光纤激光器能同时发出功率和频率都稳定的多波长激光，且每个波长都是单纵模激光；在4h内，每个波长的波长稳定性优于0.01nm。该设计对可调谐单纵模多波长光纤激光器的研究是有帮助的。

Research on tunable single-longitudinal multi-wavelength fiber laser

In order to achieve high-precision interferometric measurement of physical quantities such as step height and absolute distance, etc, an optical fiber laser was constructed which includes multiple fiber laser resonators and can emit several wavelengths simultaneously. The erbium-doped fibers were used as gain material in each laser resonator, and the fiber Bragg gratings were employed as wavelength-choosing elements. By changing the Bragg wavelength of a fiber Bragg grating, the wavelength emitted from the corresponding resonator can be changed. Each of the cavities was independent and all of the cavities were overlapped each other. In the overlapped part, optical fiber couplers were used to configure sub-cavities and thus each resonator can emit single longitudinal mode laser. The experimental results show that each of the resonators can emit single longitudinal mode laser with stable power and stable wavelength. And the stability of each wavelength can be less than 0.01 nm within 4h. This design is helpful to the research of tunable single longitudinal mode multi wavelength fiber laser.