DFB半导体激光器调谐动态波长特性研究

为了测量半导体激光器在电流调谐下的动态波长，提出了基于光纤延时自外差法的测量方案，阐述了测量原理，研究了拍频与动态波长的递推关系。应用该实验系统测量了分布反馈式半导体激光器调谐的动态波长特性，与由光谱仪测量的稳态波长特性比较。结果表明，动态波长与稳态波长随电流变化特性有着类似的非线性规律，在20~100 mA调谐范围内二者差异小于0.002 nm。此外，通过气体CO₂的两条吸收谱线与HITRAN谱库中标准吸收线位置比对，辨识出半导体激光器调谐的动态波长，该辨识出的动态波长值与由延时自外差法推算出的动态波长值比较，二者误差为1 pm，进而验证了该测量系统的可靠性。

Dynamic Wavelength Characteristics of Semiconductor Laser in Electric Current Tuning Process

In order to measure the dynamic wavelength of semiconductor lasers under current tuning, an improved method of fiber delay self-heterodyne interferometer was proposed. The measurement principle, as well the beat frequency and dynamic wavelength of recursive relations are theoretically analyzed. The application of the experimental system measured the dynamic wavelength characteristics of distributed feedback semiconductor laser and the static wavelength characteristics measurement by the spectrometer. The comparison between the two values indicates that both dynamic and static wavelength characteristic with the current tuning are the similar non-linear curve. In 20~100 mA current tuning range, the difference of them is less than 0.002 nm. At the same time, according to the absorption lines of CO₂ gas, and HITRAN spectrum library, we can identify the dynamic wavelength of the laser. Comparing it with dynamic wavelength calculated by the beat signal, the difference is only 0.001 nm, which verifies the reliability of the experimental system to measure the dynamic wavelength.