基于硫系光纤色散管理的3um光纤激光器自相似锁模脉冲特性研究

Fiber lasers at 3um band with ultra-short pulses has broad application prospect in industry, scientific research and military field. The current transmission medium of 3um fiber laser is mainly focused on fluoride fiber, which has zero dispersion wavelength of <2um and also has a large negative dispersion in the 3um band. The lack of proper dispersion compensation mechanism of the oscillator will result in low mode-locked pulse energy, pulses are easy to split, and pulses duration will be limited by the spectral side band, these will seriously restrict its performance improvement and practicality. Obtaining self-similar pulses by proper dispersion management in mode-locked fiber oscillator is an important way to broaden spectrum, boost pulses energy and narrowing pulses duration. At present, chalcogenide glass is the only infrared material with normal dispersion and good fiber forming characteristics in 3um band. Based on this, this project innovatively applies a home-made high-quality single-mode chalcogenide glass fiber to a 3um mode-locked fiber oscillator, explores the influence of intra-cavity dispersion and non-linearity on self-similar pulses characteristics, establishes a reliable theoretical model, and finally realizes a 3um stable self-similar mode-locked fiber laser source. The carrying out of this project will promote the development of novel key devices in mid-infrared laser with independent intellectual property rights and the performance improvement of 3um band ultra-short pulse fiber lasers.

3um波段超短脉冲光纤激光源在工业、科研及军事领域具有极其广阔的应用前景。由于波长特殊，当前3um光纤激光传输介质主要为氟化物光纤，其零色散波长<2um，在3um波段具有较大的负色散。振荡器缺少恰当的色散补偿机制，会造成锁模脉冲能量低，易于分裂；光谱边带限制脉宽，产生基底，影响主脉冲能量，严重制约其性能提升与实用化。通过色散管理获得自相似锁模是实现脉冲光谱扩展、能量提升、脉宽窄化的重要途径，硫系玻璃是目前唯一在3um波段呈正常色散且特性良好的红外材料。基于此，本项目创新性的将自制单模硫系玻璃光纤用于3um锁模光纤振荡器，探索腔内色散与非线性对自相似脉冲特性的影响，并建立可靠理论模型，最终实现稳定的3um自相似锁模超短脉冲光纤激光源。本项目的开展将为推动具有自主知识产权的新型中红外激光关键器件开发与3um波段超短脉冲光纤激光器性能提升奠定坚实的基础和提供可靠的科学依据。

3um波段超短脉冲光纤激光源在工业、科研及军事领域具有极其广阔的应用前景。由于波长特殊，当前3um光纤激光传输介质主要为氟化物光纤，其零色散波长<2um，在3um波段具有较大的负色散。振荡器缺少恰当的色散补偿机制，会导致锁模脉冲能量低，易于分裂；光谱边带限制脉宽，产生基底，影响主脉冲能量，严重制约其性能提升与实用化。通过色散管理获得自相似锁模是实现脉冲光谱扩展、能量提升、脉宽窄化的重要途径，硫系玻璃是目前唯一在3um波段呈正常色散且特性良好的红外材料。基于此，本项目创新性的将自制单模硫系玻璃光纤用于3um锁模光纤振荡器，探索腔内色散与非线性对自相似脉冲特性的影响，并建立可靠理论模型，最终实现稳定的3um自相似锁模超短脉冲光纤激光源。本项目的开展将为推动具有自主知识产权的新型中红外激光关键器件开发与3um波段超短脉冲光纤激光器性能提升奠定坚实的基础和提供可靠的科学依据。