基于超快光克尔效应的超短脉冲光限幅器

Optical Limiter for Ultrashort Laser Pulses Baesd on Ultrafast Optical Kerr Effect

超短脉冲激光因其独特的传播性质,在光电对抗领域具有重要的应用潜力。针对传统光限幅器件在超短脉冲激光限幅防护领域中存在的若干问题,提出一种基于超快光克尔效应的超短脉冲光限幅器。该限幅技术利用超短脉冲在非线性介质中诱导非线性偏振椭圆旋转(NER)效应,可实现超低阈值的光限幅输出,同时将非线性偏振椭圆旋转和自聚焦效应相结合,可保证器件在较大动态能量范围内具备限幅功能,该器件具备响应速度快、适用光谱范围宽的优点。系统阐述了NER效应的基本原理,并利用飞秒脉冲激光验证了基于NER和自聚焦效应的光限幅器的限幅性能。

Ultrashort pulse laser has important potential applications in the field of optoelectronic countermeasure because of its unique propagation features. An ultrafast optical limiter based on optical Kerr effect for ultrashort laser pulses is proposed on account of the problems in the traditional optical limiting （OL） method. The proposed OL technique utilizes the nonlinear polarization ellipse rotation （NER） effect induced in nonlinear materials to realize an excellent OL performance with ultra-low activating threshold. By combining NER and self-focusing effects, the proposed optical limiter can be used in a large dynamic range. The proposed optical limiter also has advantages of ultrafast response time and wide applicable spectral range. The basic principles of NER effects is discussed systematiclly, and OL performance of the limiter is verified using a femtosecond pulse laser.