Regimes of external optical feedback in 5.6 μm distributed feedback mid-infrared quantum cascade lasers

摘要: External optical feedback is studied experimentally in mid-infrared quantum cascade lasers. These structures exhibit a dynamical response close to that observed interband lasers, with threshold reduction and power enhancement when increasing the ratio. The study of spectrum proves laser undergoes five distinct regimes depending on phase amplitude reinjected field. are mapped plane external cavity length strength, revealing unstable behavior only for very narrow range operation, making lasers much more stable than their counterparts.