提出一种新型的宽带倍频方案，利用时空耦合效应将宽带的时间啁啾光转换成空间啁啾光，采用多块晶体并联、各晶体独立调谐的技术途径对空间啁啾光进行谐波转换，因此倍频效率与窄带激光倍频相当。理论研究表明，采用KDP晶体I类位相匹配，对中心波长为1 053 nm的宽带基频光实现了带宽约30 nm、转换效率大于60%的高效率宽带二倍频。而且倍频光仍为线性啁啾宽带光，具备可压缩性。

Efficient broadband harmonic conversion has important application value in high power laser. However, it is difficult to achieve broad bandwidth and high efficiency at the same time in the traditional second harmonic generation (SHG). This paper proposes a novel broadband SHG scheme, which uses the space-time coupling effect to transform the temporally chirped pulse into a spatially chirped one, and then several spliced crystals are used to achieve efficient broadband frequency conversion. Simulation results show that for the spliced KDP crystal, the conversion efficiency of the fundamental harmonic reaches about 60%, for pulse bandwidth of 30 nm and central wavelength of 1 053 nm. Moreover, the frequency doubled light is still linear and broadband, and can be compressed as the fundamental pulse.