We roundly investigate the chaos and hyperchaos of DREFL from different aspect embodying the character of chaos and find that DREFL can be in chaotic or hyperchaotic state at some conditions.

• 从表现混沌的不同侧面对双环掺铒光纤激光器的混沌和超混沌进行了全面研究，在一定的参数条件下，双环掺铒光纤激光器存在混沌和超混沌状态。