Opt Lett. 2013 Aug 15;38(16):2938-40. doi: 10.1364/OL.38.002938.
Sub-20-fs deep ultraviolet (DUV) pulses are generated by using nondegenerate, chirped-pulse four-wave mixing of the fundamental and second-harmonic pulses from a commercial Ti:sapphire amplifier in a CaF(2) plate. The energy of the DUV pulses is 3.8 μJ, with a conversion efficiency from total pump energy to DUV of ~3.8%. The DUV pulse is compressed using a pre-chirp, introduced via a fused silica window in the fundamental beam. The central wavelength of the DUV spectrum can be tuned from 257 to 277 nm by adjusting the cross angle between the two pump beams. The spectrum can reach a width of 16.8 nm, which can support a pulse duration of 8.7 fs.
利用商业钛宝石放大器产生的基频和倍频脉冲在氟化钙晶体中非简并啁啾脉冲四波混频，产生了 20fs 以下的深紫外（DUV）脉冲。DUV 脉冲的能量为 3.8μJ，总泵浦能量到 DUV 的转换效率约为 3.8%。通过在基频光束中引入预啁啾，可以对 DUV 脉冲进行压缩。通过调整两束泵浦光的交叉角，DUV 光谱的中心波长可以从 257nm 调谐到 277nm。光谱宽度可达 16.8nm，可支持 8.7fs 的脉冲持续时间。
