波长扫描激光器是光纤传感和光学相干层析技术中的关键部件,其动态输出光谱特性决定了传感与成像系统的分辨率水平。采用改进的外差法和电光调制器(EOM)法对自制的波长扫描激光器的输出光谱进行动态测量,得到光谱线宽(反映光源的相干性)及其与波长扫描频率的关系。结果表明,输出光谱线宽随着波长扫描频率增大而增加,EOM法比外差法测得的光谱线宽略大,波长扫描频率为60 k Hz时,外差法测量激光器输出光谱线宽在4.9 pm,EOM法测得为37 pm。 Wavelength scanning lasers are key components in fiber sensing and optical coherence tomography and their dynamic output spectral characteristics determine the resolution of sensing and imaging systems. An improved heterodyne method and electro-optic modulator (EOM) method was used to measure the output spectrum of a homemade wavelength-swept laser. The spectral linewidth (reflecting the coherence of the light source) and its relationship with the wavelength of the wavelength scanning were obtained. The results show that the output spectral linewidth increases with the increase of the wavelength scanning frequency. The EOM method is slightly larger than the spectral linewidth measured by the heterodyne method. When the wavelength scanning frequency is 60 kHz, the heterodyne method measures the laser output spectral linewidth At 4.9 pm, EOM measured 37 pm.