增大基于电光相位调制的时间透镜孔径的参数调制法

Parameter Modulation to Method Expand Aperture of Time Lens Based on Electro-Optical Phase Modulation

提出了一种用于增大基于电光相位调制时间透镜孔径的参数调制法,理论推导出该方法的实现原理,并结合时间透镜在光脉冲压缩中的应用,研究了调制参数Q对时间孔径和脉冲压缩效果的影响。结果表明,对于文中调制频率为20GHz,理想压缩系数为5的时间成像系统,采用这种方法可将仅占调制周期15.6%的时间孔径提高到50%以上,并将脉冲压缩系数由3.11提升到4.46。同时,通过选取相反的输入和输出段色散,还可有效降低时间系统的调制电压。研究结果表明,该参数调制法只需对时间透镜本身参数做调整,无需引入新器件,便可有效地增大时间透镜的孔径,提高脉冲压缩系数,使其更接近理想值。该研究成果为电光相位调制时间透镜系统的性能提升提供了一种简洁而有效的手段。

A parameter modulation method is proposed to increase the aperture of time lens implemented by electro- optic phase modulation. The implementing principle of this method is theoretically deduced. The effects of modulation parameter Q on the aperture of time lens and pulse compression ratio are discussed for the application of optical pulse compression with time lens. Numerical results illustrate that the proposed method can extend the aperture from 15.6 % to more than 50 % of whole modulation period and increase the compression ratio from 3.11 to 4.46 for the temporal imaging system with ideal compression ratio of 5 at the modulation frequency of 20 GHz. Besides, modulation voltage in high-frequency temporal imaging system can be reduced by selecting input and output fiber with opposite second order dispersion. The parameter modulation method can effectively improve the aperture of time lens implemented by electro-optic phase modulation and optical pulse compression ratio in temporal imaging system by only adjusting the modulation voltage of electro-optic phase modulation without other components. This method can offer a simple and effective way to improve the performance of time lens based on electro-optic phase modulation.