In wavelength-tunable EDFL, the wavelength shifting phenomenon results from the different intracavity loss by adjusting the output coupling ratio with a tunable-ratio optical coupler (TROC).

• 而波长可调的掺铒光纤雷射是在不同输出耦合比下，拥有的内腔损失也不同所造成波长偏移的现象。