The temporal coherence of chaotic laser

摘要

Temporal coherence of chaotic light with dynamically fluctuating in the state of polarization out of a fiber ring laser based on semiconductor optical amplifier (SOA) is investigated. The coherence of the chaotic light is verified by employing Sagnac interferometer, and only the zero-order coherence is observed. Visibility of interference streak is measured in different optical path differences by M-Z interferometer and coherence time of the chaotic laser with 40ps is obtained. Spectrum of the chaotic laser is measured, which is almost the same as that of normal laser light. According to the spectrum, coherence length of the chaotic light is 13mm, then, the coherence time is 43ps, which is basically consistent with the time of 40ps obtained from the experiment. Also it is got that temporal coherence of the chaotic light is independent on current of SOA by experiment. Finally, the superiority of chaos laser's coherence in resolution and sensitivity is indicated when it is applied to the field of low coherence optical source detection.