Gerz, D.D.GerzSchweinberger, W.W.SchweinbergerButler, T.P.T.P.ButlerSiefke, T.T.SiefkeHeusinger, M.M.HeusingerAmotchkina, T.T.AmotchkinaPervak, V.V.PervakZeitner, U.U.ZeitnerPupeza, I.I.Pupeza2022-03-142022-03-142019https://publica.fraunhofer.de/handle/publica/41114510.1109/CLEOE-EQEC.2019.88718132-s2.0-85084522975In recent years, the development of high-power, near-infrared (NIR) femtosecond lasers has enabled a new class of broadband mid-infrared (MIR) radiation sources that combine the spectral coverage of the molecular fingerprint region, a brilliance exceeding even that of 3 rd -generation synchrotrons, and outstanding temporal coherence. One of the challenges that arises in the development of these sources is the need to separate a tens-of-Watts NIR beam from the broadband MIR beam arising out of a parametric process such as intra-pulse difference frequency generation (IPDFG) in a suitable nonlinear crystal. Conventional coated optics face the issues of adding significant amount of dispersion to a temporally well-compressed pulse and the linear and nonlinear absorption restrict the usable NIR power in many MIR-transparent materials, such as germanium.en620conference paper